ESP-AT User Guide¶

This is the documentation for the ESP-AT.


Get Started	AT Binary Lists	AT Command Set

AT Command Examples	Compile and Develop	Customized AT Commands and Firmware

Get Started¶

[中文]

This Get Started guide provides users with detailed information on what is ESP-AT, how to connect hardware, and how to download and flash AT firmware. It consists of the following parts:

What is ESP-AT¶

[中文]

ESP-AT is a solution developed by Espressif to integrate connectivity into customers’ products, which can be quickly moved to mass production. It aims to reduce software development costs and quickly form products. With ESP-AT commands, you can quickly join the wireless network, connect to the cloud platform, realize data transmission and remote control functions, and realize the interconnection of everything through wireless communication easily.

ESP-AT is a project based on ESP-IDF or ESP8266_RTOS_SDK. It makes an ESP board work as a slave, and an MCU as a host. The host MCU sends AT commands to the ESP chip and receives AT responses back. ESP-AT provides a wide range of AT commands with different functions, such as Wi-Fi commands, TCP/IP commands, Bluetooth LE commands, Bluetooth commands, MQTT commands, HTTP commands, and Ethernet commands.

Note

Currently, ESP-AT is based on ESP-IDF or ESP8266_RTOS_SDK, not ESP8266 NonOS SDK.

AT commands start with “AT”, which stand for “Attention”, and end with a new line (CR LF). Every time you send a command, you will reveive an OK or ERROR, which indicates the final execution status of the current command. Please be noted that all commands are executed serially, which means only one AT command can be executed at a time. Therefore, you should wait for the previous command to be executed before sending out the next one. Otherwise, you will receive busy P.... For more details about AT commands, please refer to AT Command Set.

By default, the host MCU connects to the ESP board via UART, and sends/receives AT commands/responses through UART. But you can also use other interfaces, such as SDIO, according to your actual use scenario.

You can develop your own AT commands based on our ESP-AT project and implement more features according to your actual use scenario.

Hardware Connection¶

[中文]

This document introduces what hardware you need to prepare and how to connect them in order to download AT firmware, send AT commands, and receive AT responses. It covers the following four ESP series of modules:

ESP32 Series
ESP32-S2 Series
ESP32-C3 Series
ESP8266 Series

For different series of modules, the commands supported by AT firmware are different. Please refer to How to understand the differences of each type of module for more details.

What You Need¶

List of Components Required for ESP-AT Testing¶
Component	Function
ESP board	Slave MCU.
USB cable (ESP borad to PC)	Download/Log output connection.
PC	Act as Host MCU. Download firmware to Slave MCU.
USB cable (PC to serial port converter)	AT command/response connection.
USB to serial port converter	Convert between USB signals and TTL signals.
Jumper wires (serial port converter to ESP board)	AT command/response connection.

Connection of Components for ESP-AT Testing¶

Please note that in the above picture, four jump wires are used to connect the ESP board and USB to serial converter. If you don’t use hardware flow control, two wires connecting TX/RX and a simpler converter will be enough.

ESP32 Series¶

ESP32 AT uses two UART ports: UART0 is used to download firmware and log output; UART1 is used to send AT commands and receive AT responses.

All ESP32 modules use GPIO1 and GPIO3 as UART0, but they use different GPIOs as UART1. The following sections illustrate which GPIOs you should connect for each ESP32 series of modules.

For more details of ESP32 modules and boards, please refer to ESP32 modules and ESP32 boards.

ESP32-WROOM-32 Series¶

ESP32-WROOM-32 Series Hardware Connection Pinout¶
Function of Connection	ESP Board Pins	Other Device Pins
Download/Log output ¹	UART0 GPIO3 (RX) GPIO1 (TX)	PC TX RX
AT command/response ²	UART1 GPIO16 (RX) GPIO17 (TX) GPIO15 (CTS) GPIO14 (RTS)	USB to serial converter TX RX RTS CTS

Note 1: Connection between individual pins of the ESP board and the PC is already established internally on the ESP board. You only need to provide USB cable between the board and PC.

Note 2: Connection between CTS/RTS is optional, depending on whether you want to use hardware flow control.

ESP32-WROOM-32 Series Hardware Connection¶

If you want to connect your device directly with ESP32-WROOM-32 rather than the ESP board that integrates it, please refer to ESP32-WROOM-32 Datasheet for more details.

ESP32-WROVER Series¶

ESP32-WROVER Series Hardware Connection Pinout¶
Function of Connection	ESP Board Pins	Other Device Pins
Download/Log output ¹	UART0 GPIO3 (RX) GPIO1 (TX)	PC TX RX
AT command/response ²	UART1 GPIO19 (RX) GPIO22 (TX) GPIO15 (CTS) GPIO14 (RTS)	USB to serial converter TX RX RTS CTS

Note 1: Connection between individual pins of the ESP board and the PC is already established internally on the ESP board. You only need to provide USB cable between the board and PC.

Note 2: Connection between CTS/RTS is optional, depending on whether you want to use hardware flow control.

ESP32-WROVER Series Hardware Connection¶

If you want to connect your device directly with ESP32-WROVER rather than the ESP board that integrates it, please refer to ESP32-WROVER Datasheet for more details.

ESP32-PICO Series¶

ESP32-PICO Series Hardware Connection Pinout¶
Function of Connection	ESP Board Pins	Other Device Pins
Download/Log output ¹	UART0 GPIO3 (RX) GPIO1 (TX)	PC TX RX
AT command/response ²	UART1 GPIO19 (RX) GPIO22 (TX) GPIO15 (CTS) GPIO14 (RTS)	USB to serial converter TX RX RTS CTS

Note 1: Connection between individual pins of the ESP board and the PC is already established internally on the ESP board. You only need to provide USB cable between the board and PC.

Note 2: Connection between CTS/RTS is optional, depending on whether you want to use hardware flow control.

If you want to connect your device directly with ESP32-PICO-D4 rather than the ESP board that integrates it, please refer to ESP32-PICO-D4 Datasheet for more details.

ESP32-SOLO Series¶

ESP32-SOLO Series Hardware Connection Pinout¶
Function of Connection	ESP Board Pins	Other Device Pins
Download/Log output ¹	UART0 GPIO3 (RX) GPIO1 (TX)	PC TX RX
AT command/response ²	UART1 GPIO16 (RX) GPIO17 (TX) GPIO15 (CTS) GPIO14 (RTS)	USB to serial converter TX RX RTS CTS

Note 1: Connection between individual pins of the ESP board and the PC is already established internally on the ESP board. You only need to provide USB cable between the board and PC.

Note 2: Connection between CTS/RTS is optional, depending on whether you want to use hardware flow control.

If you want to connect your device directly with ESP32-SOLO-1 rather than the ESP board that integrates it, please refer to ESP32-SOLO-1 Datasheet for more details.

ESP32-S2 Series¶

ESP32-S2 AT uses two UART ports: UART0 is used to download firmware and log output; UART1 is used to send AT commands and receive AT responses.

ESP32-S2 Series Hardware Connection Pinout¶
Function of Connection	ESP Board Pins	Other Device Pins
Download/Log output ¹	UART0 GPIO44 (RX) GPIO43 (TX)	PC TX RX
AT command/response ²	UART1 GPIO21 (RX) GPIO17 (TX) GPIO20 (CTS) GPIO19 (RTS)	USB to serial converter TX RX RTS CTS

Note 1: Connection between individual pins of the ESP board and the PC is already established internally on the ESP board. You only need to provide USB cable between the board and PC.

Note 2: Connection between CTS/RTS is optional, depending on whether you want to use hardware flow control.

If you want to connect your device directly with ESP32-S2-WROOM rather than the ESP board that integrates it, please refer to ESP32-S2-WROOM & ESP32-S2-WROOM-I Datasheet for more details.

ESP32-C3 Series¶

ESP32-C3 AT uses two UART ports: UART0 is used to download firmware and log output; UART1 is used to send AT commands and receive AT responses.

ESP32-C3 Series Hardware Connection Pinout¶
Function of Connection	ESP Board Pins	Other Device Pins
Download/Log output ¹	UART0 GPIO20 (RX) GPIO21 (TX)	PC TX RX
AT command/response ²	UART1 GPIO6 (RX) GPIO7 (TX) GPIO5 (CTS) GPIO4 (RTS)	USB to serial converter TX RX RTS CTS

Note 1: Connection between individual pins of the ESP board and the PC is already established internally on the ESP board. You only need to provide USB cable between the board and PC.

Note 2: Connection between CTS/RTS is optional, depending on whether you want to use hardware flow control.

If you want to connect your device directly with ESP32-C3-MINI-1 rather than the ESP board that integrates it, please refer to ESP32-C3-MINI-1 Datasheet for more details.

ESP8266 Series¶

ESP8266 AT uses two UART ports: UART0 is used to download firmware and send AT commands and receive AT responses; UART1 is used to log output.

ESP8266 Series Hardware Connection Pinout¶
Function of Connection	ESP Board Pins	Other Device Pins
Download	UART0 GPIO3 (RX) GPIO1 (TX)	PC TX RX
AT command/response ²	UART0 GPIO13 (RX) GPIO15 (TX) GPIO3 (CTS) GPIO1 (RTS)	USB to serial converter TX RX RTS CTS
Log output	UART1 GPIO2 (TX)	USB to serial converter RX

Note 1: Connection between individual pins of the ESP board and the PC is already established internally on the ESP board. You only need to provide USB cable between the board and PC.

Note 2: Connection between CTS/RTS is optional, depending on whether you want to use hardware flow control.

Note

The default ESP8266 RTOS AT firmware for ESP-WROOM-02 swaps RX/TX with CTS/RTS. If you want to use hardware flow control, you need to disconnect UART1, desolder CP2102N chip from the ESP board, and connect the board with 3.3 V and GND of the converter to supply power.

If you design your module based on the ESP8266 chip and use GPIO15/GPIO13 as the AT commands communication, then you need to pay attention to the layout of GPIO5 pin. For more information, please see ESP8266 Hardware Design Guidelines > Figure ESP8266EX UART SWAP.

In ESP8266 AT released firmware, GPIO5 will output high level after power on to control the conduction state between GPIO15 and MCU.

If you want to connect your device directly with ESP-WROOM-02 or ESP-WROOM-02D/02U rather than the ESP board that integrates it, please refer to ESP-WROOM-02 Datasheet or ESP-WROOM-02D/02U Datasheet for more details.

For more details about ESP8266 modules, please refer to ESP8266 documentation.

Downloading Guide¶

[中文]

This Guide demonstrates how to download AT firmware and flash it into an ESP device by taking ESP32-WROOM-32 as an example. The Guide is also applicable to other ESP modules.

Before you start, please make sure you have already connected your hardware. For more details, see Hardware Connection.

For different series of modules, the commands supported by AT firmware are different. Please refer to How to understand the differences of each type of module for more details.

Download AT Firmware¶

To download AT firmware to your computer, please do as follows:

Navigate to AT Binary Lists
Find the firmware for your device
Click the link to download it

Here, we download ESP32-WROOM-32_AT_Bin_V2.1 for ESP32-WROOM-32. The list below describes the structure of this firmware and what each bin file contains. Other AT firmware has similar structure and bin files.

.
├── at_customize.bin                 // secondary partition table
├── bootloader                       // bootloader
│   └── bootloader.bin
├── customized_partitions            // AT customized binaries
│   ├── ble_data.bin
│   ├── client_ca.bin
│   ├── client_cert.bin
│   ├── client_key.bin
│   ├── factory_param.bin
│   ├── factory_param_WROOM-32.bin
│   ├── mqtt_ca.bin
│   ├── mqtt_cert.bin
│   ├── mqtt_key.bin
│   ├── server_ca.bin
│   ├── server_cert.bin
│   └── server_key.bin
├── download.config                  // configuration of downloading
├── esp-at.bin                       // AT application binary
├── factory                          // A combined bin for factory downloading
│   ├── factory_WROOM-32.bin
│   └── factory_parameter.log
├── flasher_args.json                // flasher arguments
├── ota_data_initial.bin             // ota data parameters
├── partition_table                  // primary partition table
│   └── partition-table.bin
└── phy_init_data.bin                // phy parameters

The file download.config contains the configuration to flash the firmware into multiple addresses:

--flash_mode dio --flash_freq 40m --flash_size 4MB
0x8000 partition_table/partition-table.bin
0x10000 ota_data_initial.bin
0xf000 phy_init_data.bin
0x1000 bootloader/bootloader.bin
0x100000 esp-at.bin
0x20000 at_customize.bin
0x24000 customized_partitions/server_cert.bin
0x39000 customized_partitions/mqtt_key.bin
0x26000 customized_partitions/server_key.bin
0x28000 customized_partitions/server_ca.bin
0x2e000 customized_partitions/client_ca.bin
0x30000 customized_partitions/factory_param.bin
0x21000 customized_partitions/ble_data.bin
0x3B000 customized_partitions/mqtt_ca.bin
0x37000 customized_partitions/mqtt_cert.bin
0x2a000 customized_partitions/client_cert.bin
0x2c000 customized_partitions/client_key.bin

--flash_mode dio means the firmware is compiled with flash DIO mode.
--flash_freq 40m means the firmware’s flash frequency is 40 MHz.
--flash_size 4MB means the firmware is using flash size 4 MB.
0x10000 ota_data_initial.bin means downloading ota_data_initial.bin into the address 0x10000.

Flash AT Firmware into Your Device¶

Follow the instructions below for your operating system.

Windows¶

Before starting to flash, you need to download Flash Download Tools for Windows. For more details about the tools, please see readme.pdf or the doc folder in the zip folder.

Open the ESP Flash Download Tool.
Select a mode according to your need. (Here, we select Developer Mode.)

Select your target chip. For example, choose “ESP8266 DownloadTool” for ESP8266 chip; choose “ESP32-S2 DownloadTool” for ESP32-S2 chip. (Here, we select ESP32 DownloadTool.)

Flash Download Tools Target Chips — Flash Download Tools Target Chip¶

Flash AT firmware into your device. You can select either of the two ways below.
- To download one combined factory bin to address 0, select “DoNotChgBin” to use the default configuration of the factory bin.
  
  Download to One Address¶
- To download multiple bins separately to different addresses, set up the configurations according to the file download.config and do NOT select “DoNotChgBin”.
  
  Download to Multiple Addresses¶

In case of flashing issues, please verify what the COM port number of download interface of the ESP board is and select it from “COM:” dropdown list. If you don’t know the port number, you can refer to Check port on Windows for details.

When you finish flashing, please Check Whether AT Works.

Linux or macOS¶

Before you start to flash, you need to install esptool.py.

You can select either of the two ways below to flash AT firmware into your device.

To download the bins separately into multiple addresses, enter the following command and replace PORTNAME and download.config:

esptool.py --chip auto --port PORTNAME --baud 115200 --before default_reset --after hard_reset write_flash -z download.config

Replace PORTNAME with your port name. If you don’t know it, you can refer to Check port on Linux and macOS for details.

Replace download.config with the content inside the file.

Below is the example command for ESP32-WROOM-32.

esptool.py --chip auto --port /dev/tty.usbserial-0001 --baud 115200 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size 4MB 0x8000 partition_table/partition-table.bin 0x10000 ota_data_initial.bin 0xf000 phy_init_data.bin 0x1000 bootloader/bootloader.bin 0x100000 esp-at.bin 0x20000 at_customize.bin 0x24000 customized_partitions/server_cert.bin 0x39000 customized_partitions/mqtt_key.bin 0x26000 customized_partitions/server_key.bin 0x28000 customized_partitions/server_ca.bin 0x2e000 customized_partitions/client_ca.bin 0x30000 customized_partitions/factory_param.bin 0x21000 customized_partitions/ble_data.bin 0x3B000 customized_partitions/mqtt_ca.bin 0x37000 customized_partitions/mqtt_cert.bin 0x2a000 customized_partitions/client_cert.bin 0x2c000 customized_partitions/client_key.bin

To download the bins together to one address, enter the following command and replace PORTNAME and FILEDIRECTORY:

esptool.py --chip auto --port PORTNAME --baud 115200 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size 4MB 0x0 FILEDIRECTORY

Replace PORTNAME with your port name. If you don’t know it, you can refer to Check port on Linux and macOS for details.

Replace FILEDIRECTORY with the file directory you would flash to the address 0x0. It is normally factory/XXX.bin.

Below is the example command for ESP32-WROOM-32.

esptool.py --chip auto --port /dev/tty.usbserial-0001 --baud 115200 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size 4MB 0x0 factory/factory_WROOM-32.bin

When you finish flashing, please Check Whether AT Works.

Check Whether AT Works¶

To check whether AT works, do as follows:

Open a serial port tool, such as SecureCRT;
Select the Port attached to “AT command/response” line (see Hardware Connection for details);
Set Baudrate to 115200;
Set Data Bits to 8;
Set Parity to None;
Set Stop Bits to 1;
Set Flow Type to None;
Enter the command “AT+GMR” with a new line (CR LF).

If the response is OK as the picture below shows, it means that AT works.

Otherwise, you need to check your ESP startup log, which is visible on PC over “Download/Log output connection”. If it is like the log below, it means that ESP-AT firmware have been initalized correctly.

ESP32 startup log:

ets Jun  8 2016 00:22:57
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0030,len:4
load:0x3fff0034,len:7184
ho 0 tail 12 room 4
load:0x40078000,len:13200
load:0x40080400,len:4564
entry 0x400806f4
I (30) boot: ESP-IDF v4.2 2nd stage bootloader
I (31) boot: compile time 11:23:19
I (31) boot: chip revision: 0
I (33) boot.esp32: SPI Speed      : 40MHz
I (38) boot.esp32: SPI Mode       : DIO
I (42) boot.esp32: SPI Flash Size : 4MB
I (47) boot: Enabling RNG early entropy source...
I (52) boot: Partition Table:
I (56) boot: ## Label            Usage          Type ST Offset   Length
I (63) boot:  0 phy_init         RF data          01 01 0000f000 00001000
I (71) boot:  1 otadata          OTA data         01 00 00010000 00002000
I (78) boot:  2 nvs              WiFi data        01 02 00012000 0000e000
I (86) boot:  3 at_customize     unknown          40 00 00020000 000e0000
I (93) boot:  4 ota_0            OTA app          00 10 00100000 00180000
I (101) boot:  5 ota_1            OTA app          00 11 00280000 00180000
I (108) boot: End of partition table
I (112) esp_image: segment 0: paddr=0x00100020 vaddr=0x3f400020 size=0x2a300 (172800) map
I (187) esp_image: segment 1: paddr=0x0012a328 vaddr=0x3ffbdb60 size=0x039e8 ( 14824) load
I (194) esp_image: segment 2: paddr=0x0012dd18 vaddr=0x40080000 size=0x00404 (  1028) load
I (194) esp_image: segment 3: paddr=0x0012e124 vaddr=0x40080404 size=0x01ef4 (  7924) load
I (206) esp_image: segment 4: paddr=0x00130020 vaddr=0x400d0020 size=0x10a470 (1090672) map
I (627) esp_image: segment 5: paddr=0x0023a498 vaddr=0x400822f8 size=0x1c3a0 (115616) load
I (678) esp_image: segment 6: paddr=0x00256840 vaddr=0x400c0000 size=0x00064 (   100) load
I (695) boot: Loaded app from partition at offset 0x100000
I (695) boot: Disabling RNG early entropy source...
max tx power=78,ret=0
2.1.0

ESP32-S2 startup log:

ESP-ROM:esp32s2-rc4-20191025
Build:Oct 25 2019
rst:0x1 (POWERON),boot:0x8 (SPI_FAST_FLASH_BOOT)
SPIWP:0xee
mode:DIO, clock div:1
load:0x3ffe6100,len:0x4
load:0x3ffe6104,len:0x1a24
load:0x4004c000,len:0x1a6c
load:0x40050000,len:0x20fc
entry 0x4004c35c
I (46) boot: ESP-IDF v4.2 2nd stage bootloader
I (46) boot: compile time 11:24:34
I (46) boot: chip revision: 0
I (47) qio_mode: Enabling default flash chip QIO
I (53) boot.esp32s2: SPI Speed      : 80MHz
I (57) boot.esp32s2: SPI Mode       : QIO
I (62) boot.esp32s2: SPI Flash Size : 4MB
I (67) boot: Enabling RNG early entropy source...
I (72) boot: Partition Table:
I (76) boot: ## Label            Usage          Type ST Offset   Length
I (83) boot:  0 phy_init         RF data          01 01 0000f000 00001000
I (91) boot:  1 otadata          OTA data         01 00 00010000 00002000
I (98) boot:  2 nvs              WiFi data        01 02 00012000 0000e000
I (106) boot:  3 at_customize     unknown          40 00 00020000 000e0000
I (113) boot:  4 ota_0            OTA app          00 10 00100000 00180000
I (121) boot:  5 ota_1            OTA app          00 11 00280000 00180000
I (128) boot: End of partition table
I (133) esp_image: segment 0: paddr=0x00100020 vaddr=0x3f000020 size=0x21bec (138220) map
I (167) esp_image: segment 1: paddr=0x00121c14 vaddr=0x3ffc9330 size=0x02fe0 ( 12256) load
I (169) esp_image: segment 2: paddr=0x00124bfc vaddr=0x40024000 size=0x00404 (  1028) load
I (173) esp_image: segment 3: paddr=0x00125008 vaddr=0x40024404 size=0x0b010 ( 45072) load
I (193) esp_image: segment 4: paddr=0x00130020 vaddr=0x40080020 size=0xb0784 (722820) map
I (324) esp_image: segment 5: paddr=0x001e07ac vaddr=0x4002f414 size=0x09f18 ( 40728) load
I (334) esp_image: segment 6: paddr=0x001ea6cc vaddr=0x40070000 size=0x0001c (    28) load
I (346) boot: Loaded app from partition at offset 0x100000
I (346) boot: Disabling RNG early entropy source...
max tx power=78,ret=0
2.1.0

ESP32-C3 startup log:

ESP-ROM:esp32c3-20200918
Build:Sep 18 2020
rst:0x1 (POWERON),boot:0xc (SPI_FAST_FLASH_BOOT)
SPIWP:0xee
mode:DIO, clock div:2
load:0x3fcd6100,len:0x14
load:0x3fcd6114,len:0x179c
load:0x403ce000,len:0x894
load:0x403d0000,len:0x2bf8
entry 0x403ce000
I (54) boot: ESP-IDF v4.3-beta1 2nd stage bootloader
I (55) boot: compile time 12:09:42
I (55) boot: chip revision: 1
I (57) boot_comm: chip revision: 1, min. bootloader chip revision: 0
I (64) boot.esp32c3: SPI Speed      : 40MHz
I (68) boot.esp32c3: SPI Mode       : DIO
I (73) boot.esp32c3: SPI Flash Size : 4MB
I (78) boot: Enabling RNG early entropy source...
I (83) boot: Partition Table:
I (87) boot: ## Label            Usage          Type ST Offset   Length
I (94) boot:  0 phy_init         RF data          01 01 0000f000 00001000
I (102) boot:  1 otadata          OTA data         01 00 00010000 00002000
I (109) boot:  2 nvs              WiFi data        01 02 00012000 0000e000
I (117) boot:  3 at_customize     unknown          40 00 00020000 000e0000
I (124) boot:  4 ota_0            OTA app          00 10 00100000 00180000
I (132) boot:  5 ota_1            OTA app          00 11 00280000 00180000
I (139) boot: End of partition table
I (144) boot: No factory image, trying OTA 0
I (149) boot_comm: chip revision: 1, min. application chip revision: 0
I (156) esp_image: segment 0: paddr=00100020 vaddr=3c140020 size=29cc8h (171208) map
I (201) esp_image: segment 1: paddr=00129cf0 vaddr=3fc8f000 size=03be8h ( 15336) load
I (205) esp_image: segment 2: paddr=0012d8e0 vaddr=40380000 size=02738h ( 10040) load
I (210) esp_image: segment 3: paddr=00130020 vaddr=42000020 size=135bf0h (1268720) map
I (489) esp_image: segment 4: paddr=00265c18 vaddr=40382738 size=0c778h ( 51064) load
I (502) esp_image: segment 5: paddr=00272398 vaddr=50000000 size=00004h (     4) load
I (508) boot: Loaded app from partition at offset 0x100000
I (544) boot: Set actual ota_seq=1 in otadata[0]
I (544) boot: Disabling RNG early entropy source...
max tx power=78,ret=0
2.1.0

ESP8266 startup log:

...
boot: ESP-IDF v3.4-rc 2nd stage bootloader
I (54) boot: compile time 11:18:21
I (54) boot: SPI Speed      : 80MHz
I (57) boot: SPI Mode       : DIO
I (61) boot: SPI Flash Size : 2MB
I (65) boot: Partition Table:
I (68) boot: ## Label            Usage          Type ST Offset   Length
I (75) boot:  0 otadata          OTA data         01 00 00009000 00002000
I (83) boot:  1 phy_init         RF data          01 01 0000f000 00001000
I (90) boot:  2 ota_0            OTA app          00 10 00010000 000e0000
I (98) boot:  3 at_customize     unknown          40 00 000f0000 00020000
I (105) boot:  4 ota_1            OTA app          00 11 00110000 000e0000
I (112) boot:  5 nvs              WiFi data        01 02 001f0000 00010000
I (120) boot: End of partition table
I (124) boot: No factory image, trying OTA 0
I (129) esp_image: segment 0: paddr=0x00010010 vaddr=0x40210010 size=0xac0d0 (704720) map
I (138) esp_image: segment 1: paddr=0x000bc0e8 vaddr=0x402bc0e0 size=0x1aba8 (109480) map
I (146) esp_image: segment 2: paddr=0x000d6c98 vaddr=0x3ffe8000 size=0x00788 (  1928) load
I (155) esp_image: segment 3: paddr=0x000d7428 vaddr=0x40100000 size=0x00080 (   128) load
I (164) esp_image: segment 4: paddr=0x000d74b0 vaddr=0x40100080 size=0x059c4 ( 22980) load
I (173) boot: Loaded app from partition at offset 0x10000
phy_version: 1163.0, 665d56c, Jun 24 2020, 10:00:08, RTOS new
max tx power=78,ret=0
2.0.0

To learn more about ESP-AT, please read What is ESP-AT.

To get started with ESP-AT, please read Hardware Connection first to learn what hardware to prepare and how to connect them. Then, you can download and flash AT firmware into your device according to Downloading Guide.

AT Binary Lists¶

[中文]

Released Firmware¶

It is recommended to use the lastest version of firmware.

Released Firmware¶

It is recommended to use the lastest version of firmware.

ESP32-S2-WROOM Series¶

v2.1.0.0 ESP32-S2-WROOM_AT_Bin_V2.1.0.0.zip (Recommended)

ESP32-S2-WROVER Series¶

v2.1.0.0 ESP32-S2-WROVER_AT_Bin_V2.1.0.0.zip (Recommended)

ESP32-S2-SOLO Series¶

v2.1.0.0 ESP32-S2-SOLO_AT_Bin_V2.1.0.0.zip (Recommended)

ESP32-S2-MINI Series¶

v2.1.0.0 ESP32-S2-MINI_AT_Bin_V2.1.0.0.zip (Recommended)

Released Firmware¶

It is recommended to use the lastest version of firmware.

Note:
Espressif has not released a separate version for the 1 MB ESP8285/8266 series of chips, but you can refer to How to Download the Latest Temporary Version of AT Firmware from GitHub and choose to download the 1 MB firmware on the CI (Continuous Integration) of GitHub (Please switch to release/v2.2.0.0_esp8266 branch and download esp8285-1MB-at under the Artifacts page).

ESP-WROOM-02 Series¶

v2.2.1.0 ESP8266-IDF-AT_V2.2.1.0.zip (Recommended)
v2.2.0.0 ESP8266-IDF-AT_V2.2.0.0.zip
v2.1.0.0 ESP8266-IDF-AT_V2.1.0.0.zip
v2.0.0.0 ESP8266-IDF-AT_V2.0.0.0.zip

Each of the linked above ESP-AT-Bin files contains several binaries for some specific functions, and the factory/factory/xxx.bin is the combination of all binaries. So user can only download the factory/factory_xxx.bin to address 0, or several binaries to different addresses according to ESP-AT-Bin/download.config.

at_customize.bin is to provide a user partition table, which lists different partitions for the ble_data.bin, SSL certificates, and factory_param_XXX.bin. Furthermore, users can add their own users partitions, and read/write the user partitions with the command AT+FS and AT+SYSFLASH.

factory_param_XXX.bin indicates the hardware configurations for different ESP modules (see the table below). Please make sure the correct bin is used for your specific module. If users design their own module, they can configure it with reference to the esp-at/docs/en/Compile_and_Develop/How_to_create_factory_parameter_bin.md, and the binaries will be automatically generated after compilation. When users flash the firmware into module according to the download.config, the customized_partitions/factory_param.bin should be replaced with the actual module-specific customized_partitions/factory_param_XXX.bin. UART CTS and RTS pins are optional.

ESP32 Series

Modules	UART Pins (TX, RX, CTS, RTS)	Factory Parameter Bin
ESP32-WROOM-32 Series (ESP32 Default Value)	GPIO17, GPIO16, GPIO15, GPIO14	`factory_param_WROOM-32.bin`
ESP32-WROVER Series (Supports Classic Bluetooth)	GPIO22, GPIO19, GPIO15, GPIO14	`factory_param_WROVER-32.bin`
ESP32-PICO Series	GPIO22, GPIO19, GPIO15, GPIO14	`factory_param_PICO-D4.bin`
ESP32-SOLO Series	GPIO17, GPIO16, GPIO15, GPIO14	`factory_param_SOLO-1.bin`

ESP32S2 Series

Modules	UART Pins (TX, RX, CTS, RTS)	Factory Parameter Bin
ESP32S2-WROOM Series	GPIO17, GPIO21, GPIO20, GPIO19	`factory_param_WROOM.bin`
ESP32S2-WROVER Series	GPIO17, GPIO21, GPIO20, GPIO19	`factory_param_WROVER.bin`
ESP32S2-SOLO Series	GPIO17, GPIO21, GPIO20, GPIO19	`factory_param_SOLO.bin`
ESP32S2-MINI Series	GPIO17, GPIO21, GPIO20, GPIO19	`factory_param_MINI.bin`

ESP32-C3 Series

Modules	UART Pins (TX, RX, CTS, RTS)	Factory Parameter Bin
ESP32-C3-MINI Series	GPIO7, GPIO6, GPIO5, GPIO4	`factory_param_MINI-1.bin`

ESP8266 Series

Modules	UART Pins (TX, RX, CTS, RTS)	Factory Parameter Bin
ESP-WROOM-02 Series (ESP8266 Default Value)	GPIO15, GPIO13, GPIO3, GPIO1	`factory_param_WROOM-02.bin`

ble_data.bin is to provide BLE services when the ESP32 works as a BLE server;
server_cert.bin, server_key.bin and server_ca.bin are examples of SSL server‘s certificate;
client_cert.bin, client_key.bin and client_ca.bin are examples of SSL client‘s certificate.

If some of the functions are not used, then the corresponding binaries need not to be downloaded into flash.

AT Command Set¶

[中文]

Here is a list of AT commands. Some of them can only work on the ESP32 series, so they are marked as [ESP32 Only] at the beginning; those without any mark can work on all ESP series, including ESP32, ESP8266, ESP32-S2, and ESP32-C3.

Basic AT Commands¶

[中文]

AT: Test AT startup.
AT+RST: Restart a module.
AT+GMR: Check version information.
AT+CMD: List all AT commands and types supported in current firmware.
AT+GSLP: Enter Deep-sleep mode.
ATE: Configure AT commands echoing.
AT+RESTORE: Restore factory default settings of the module.
AT+UART_CUR: Current UART configuration, not saved in flash.
AT+UART_DEF: Default UART configuration, saved in flash.
AT+SLEEP: Set the sleep mode.
AT+SYSRAM: Query current remaining heap size and minimum heap size.
AT+SYSMSG: Query/Set System Prompt Information.
AT+USERRAM: Operate user’s free RAM.
AT+SYSFLASH: Query/Set User Partitions in Flash.
[ESP32 Only] AT+FS: Filesystem Operations.
AT+RFPOWER: Query/Set RF TX Power.
AT+SYSROLLBACK: Roll back to the previous firmware.
AT+SYSTIMESTAMP: Query/Set local time stamp.
AT+SYSLOG: Enable or disable the AT error code prompt.
AT+SLEEPWKCFG: Query/Set the light-sleep wakeup source and awake GPIO.
AT+SYSSTORE: Query/Set parameter store mode.
AT+SYSREG: Read/write the register.
[ESP32-S2 Only] AT+SYSTEMP: Read ESP32-S2 internal temperature.

AT: Test AT Startup¶

Execute Command¶

Command:

AT

Response:

OK

AT+RST: Restart a Module¶

Execute Command¶

Command:

AT+RST

Response:

OK

AT+GMR: Check Version Information¶

Execute Command¶

Command:

AT+GMR

Response:

<AT version info>
<SDK version info>
<compile time>
<Bin version>

OK

Parameters¶

<AT version info>: information about the esp-at core library version, which is under the directory: esp-at/components/at/lib/. Code is closed source, no plan to open.
<SDK version info>: information about the esp-at platform sdk version, which is defined in file: esp-at/module_config/module_{platform}_default/IDF_VERSION
<compile time>: the time to compile the firmware.
<Bin version>: esp-at firmware version. Version information can be modified in menuconfig.

Note¶

If you have any issues on esp-at firmware, please provide AT+GMR version information firstly.

Example¶

AT+GMR
AT version:2.2.0.0-dev(ca41ec4 - ESP32 - Sep 16 2020 11:28:17)
SDK version:v4.0.1-193-ge7ac221b4
compile time(98b95fc):Oct 29 2020 11:23:25
Bin version:2.1.0(MINI-1)

OK

AT+CMD: List all AT commands and types supported in current firmware¶

Query Command¶

Command:

AT+CMD?

Response:

+CMD:<index>,<AT command name>,<support test command>,<support query command>,<support set command>,<support execute command>

OK

Parameters¶

<index>: AT command sequence number.
<AT command name>: AT command name.
<support test command>: 0 means not supported, 1 means supported.
<support query command>: 0 means not supported, 1 means supported.
<support set command>: 0 means not supported, 1 means supported.
<support execute command>: 0 means not supported, 1 means supported.

AT+GSLP: Enter Deep-sleep Mode¶

Set Command¶

Command:

AT+GSLP=<time>

Response:

<time>

OK

Parameter¶

<time>: the duration when the device stays in Deep-sleep. Unit: millisecond. When the time is up, the device automatically wakes up, calls Deep-sleep wake stub, and then proceeds to load the application.
- For ESP32 devices:
  - 0 means restarting right now
  - the maximum Deep-sleep time is about 28.8 days (2 ³¹-1 milliseconds)
- For ESP32-S2 devices:
  - 0 means staying in Deep-sleep mode forever
  - the maximum Deep-sleep time is about 28.8 days (2 ³¹-1 milliseconds)
- For ESP8266 devices:
  - 0 means staying in Deep-sleep mode forever
  - the maximum Deep-sleep time is about 3 hours (due to hardware limitation, more time will lead to setting failure or internal time overflow)

Notes¶

For ESP8266 devices, you must connect GPIO16 to RST pin to wake them up automatically when time is up.
For all devices, affected by external factors, the theoretical and actual time of Deep-sleep will be different.
ESP8266 devices can be waken up from Deep-sleep by directly triggering the RST pin low-level pulse.

ATE: Configure AT Commands Echoing¶

Execute Command¶

Command:

ATE0

or

ATE1

Response:

OK

Parameters¶

ATE0: Switch echo off.
ATE1: Switch echo on.

AT+RESTORE: Restore Factory Default Settings¶

Execute Command¶

Command:

AT+RESTORE

Response:

OK

Notes¶

The execution of this command will restore all parameters saved in flash to factory default settings of the module.
The device will be restarted when this command is executed.

AT+UART_CUR: Current UART Configuration, Not Saved in Flash¶

Query Command¶

Command:

AT+UART_CUR?

Response:

+UART_CUR:<baudrate>,<databits>,<stopbits>,<parity>,<flow control>

OK

Set Command¶

Command:

AT+UART_CUR=<baudrate>,<databits>,<stopbits>,<parity>,<flow control>

Response:

OK

Parameters¶

<baudrate>: UART baud rate
- For ESP32 and ESP32-S2 devices, the supported range is 80 ~ 5000000.
- For ESP8266 devices, the supported rang is 80 ~ 4500000.
<databits>: data bits
- 5: 5-bit data
- 6: 6-bit data
- 7: 7-bit data
- 8: 8-bit data
<stopbits>: stop bits
- 1: 1-bit stop bit
- 2: 1.5-bit stop bit
- 3: 2-bit stop bit
<parity>: parity bit
- 0: None
- 1: Odd
- 2: Even
<flow control>: flow control
- 0: flow control is not enabled
- 1: enable RTS
- 2: enable CTS
- 3: enable both RTS and CTS

Notes¶

The Query Command will return actual values of UART configuration parameters, which may have minor differences from the set value because of the clock division.
The configuration changes will NOT be saved in flash.
To use hardware flow control, you need to connect CTS/RTS pins of your ESP device. For more details, please refer to Hardware Connection or components/customized_partitions/raw_data/factory_param/factory_param_data.csv.

Example¶

AT+UART_CUR=115200,8,1,0,3

AT+UART_DEF: Default UART Configuration, Saved in Flash¶

Query Command¶

Command:

AT+UART_DEF?

Response:

+UART_DEF:<baudrate>,<databits>,<stopbits>,<parity>,<flow control>

OK

Set Command¶

Command:

AT+UART_DEF=<baudrate>,<databits>,<stopbits>,<parity>,<flow control>

Response:

OK

Parameters¶

<baudrate>: UART baud rate
- For ESP32 and ESP32-S2 devices, the supported range is 80 ~ 5000000.
- For ESP8266 devices, the supported rang is 80 ~ 4500000.
<databits>: data bits
- 5: 5-bit data
- 6: 6-bit data
- 7: 7-bit data
- 8: 8-bit data
<stopbits>: stop bits
- 1: 1-bit stop bit
- 2: 1.5-bit stop bit
- 3: 2-bit stop bit
<parity>: parity bit
- 0: None
- 1: Odd
- 2: Even
<flow control>: flow control
- 0: flow control is not enabled
- 1: enable RTS
- 2: enable CTS
- 3: enable both RTS and CTS

Notes¶

The configuration changes will be saved in the NVS area, and will still be valid when the chip is powered on again.
To use hardware flow control, you need to connect CTS/RTS pins of your ESP device. For more details, please refer to Hardware Connection or components/customized_partitions/raw_data/factory_param/factory_param_data.csv.

Example¶

AT+UART_DEF=115200,8,1,0,3

AT+SLEEP: Set the Sleep Mode¶

Query Command¶

Command:

AT+SLEEP?

Response:

+SLEEP:<sleep mode>

OK

Set Command¶

Command:

AT+SLEEP=<sleep mode>

Response:

OK

Parameter¶

<sleep mode>:
- 0: Disable the sleep mode.
- 1: Modem-sleep DTIM mode. RF will be periodically closed according to AP DTIM.
- 2: Light-sleep mode. CPU will automatically sleep and RF will be periodically closed according to listen interval set by AT+CWJAP.
- 3: Modem-sleep listen interval mode. RF will be periodically closed according to listen interval set by AT+CWJAP.

Note¶

Modem-sleep mode and Light-sleep mode can be set only in station mode.
Before setting the Light-sleep mode, it is recommended to set the wakeup source in advance through the command AT+SLEEPWKCFG, otherwise ESP devices can’t wake up and will always be in sleep mode.
After setting the Light-sleep mode, if the Light-sleep wakeup condition is not met, ESP devices will automatically enter the sleep mode. When the Light-sleep wakeup condition is met, ESP devices will automatically wake up from sleep mode.
The query command can return 0, 1, 3, but not 2 (Due to query is not supported by ESP-IDF). That is to say, AT+SLEEP? will return 3 but not 2, if set AT+SLEEP=2.

Example¶

AT+SLEEP=0

AT+SYSRAM: Query Current Remaining Heap Size and Minimum Heap Size¶

Query Command¶

Command:

AT+SYSRAM?

Response:

+SYSRAM:<remaining RAM size>,<minimum heap size>
OK

Parameters¶

<remaining RAM size>: current remaining heap size. Unit: byte.
<minimum heap size>: minimum heap size that has ever been available. Unit: byte.

Example¶

AT+SYSRAM?
+SYSRAM:148408,84044
OK

AT+SYSMSG: Query/Set System Prompt Information¶

Query Command¶

Function:

Query the current system prompt information state.

Command:

AT+SYSMSG?

Response:

+SYSMSG:<state>
OK

Set Command¶

Function:

Configure system prompt information.

Command:

AT+SYSMSG=<state>

Response:

OK

Parameter¶

<state>:
- Bit0: Prompt information when quitting Wi-Fi Passthrough Mode.
  - 0: Print no prompt information when quitting Wi-Fi Passthrough Mode.
  - 1: Print +QUITT when quitting Wi-Fi Passthrough Mode.
- Bit1: Connection prompt information type.
  - 0: Use simple prompt information, such as XX,CONNECT.
  - 1: Use detailed prompt information, such as +LINK_CONN:status_type,link_id,ip_type,terminal_type,remote_ip,remote_port,local_port.
- Bit2: Connection status prompt information for Wi-Fi Passthrough Mode, Bluetooth LE SPP and Bluetooth SPP.
  - 0: Print no prompt information.
  - 1: Print one of the following prompt information when Wi-Fi, socket, Bluetooth LE or Bluetooth status is changed:
  - "CONNECT\r\n" or the message prefixed with "+LINK_CONN:" - "CLOSED\r\n" - "WIFI CONNECTED\r\n" - "WIFI GOT IP\r\n" - "WIFI GOT IPv6 LL\r\n" - "WIFI GOT IPv6 GL\r\n" - "WIFI DISCONNECT\r\n" - "+ETH_CONNECTED\r\n" - "+ETH_DISCONNECTED\r\n" - the message prefixed with "+ETH_GOT_IP:" - the message prefixed with "+STA_CONNECTED:" - the message prefixed with "+STA_DISCONNECTED:" - the message prefixed with "+DIST_STA_IP:" - the message prefixed with "+BLECONN:" - the message prefixed with "+BLEDISCONN:"

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
If you set Bit0 to 1, it will prompt “+QUITT” when you quit Wi-Fi Passthrough Mode.
If you set Bit1 to 1, it will impact the information of command AT+CIPSTART and AT+CIPSERVER. It will supply “+LINK_CONN:status_type,link_id,ip_type,terminal_type,remote_ip,remote_port,local_port” instead of “XX,CONNECT”.

Example¶

// print no promt info when quitting Wi-Fi passthrough mode
// print detailed connection prompt info
// print no prompt info when the connection status is changed
AT+SYSMSG=2

AT+USERRAM: Operate user’s free RAM¶

Query Command¶

Function:

Query the current available user’s RAM size.

Command:

AT+USERRAM?

Response:

+USERRAM:<size>
OK

Set Command¶

Function:

Operate user’s free RAM

Command:

AT+USERRAM=<operation>,<size>[,<offset>]

Response:

::

+USERRAM:<length>,<data> // esp-at returns this response only when the operator is read

OK

Parameters¶

<operation>:
- 0: release user’s RAM
- 1: malloc user’s RAM
- 2: write user’s RAM
- 3: read user’s RAM
- 4: clear user’s RAM
<size>: the size to malloc/read/write
<offset>: the offset to read/write. Default: 0

Notes¶

Please malloc the RAM size before you perform any other operations.
If the operator is write, wrap return > after the write command, then you can send the data that you want to write. The length should be parameter <length>.
If the operator is read and the length is bigger than 1024, ESP-AT will reply multiple times in the same format, each reply can carry up to 1024 bytes of data, and eventually end up with \r\nOK\r\n.

Example¶

// malloc 1 KB user's RAM
AT+USERRAM=1,1024

// write 500 bytes to RAM (offset: 0)
AT+USERRAM=2,500

// read 64 bytes from RAM offset 100
AT+USERRAM=3,64,100

// free the user's RAM
AT+USERRAM=0

AT+SYSFLASH: Query/Set User Partitions in Flash¶

Query Command¶

Function:

Query user partitions in flash.

Command:

AT+SYSFLASH?

Response:

+SYSFLASH:<partition>,<type>,<subtype>,<addr>,<size>
OK

Set Command¶

Function:

Read/write the user partitions in flash.

Command:

AT+SYSFLASH=<operation>,<partition>,<offset>,<length>

Response:

+SYSFLASH:<length>,<data>
OK

Parameters¶

<operation>:
- 0: erase sector
- 1: write data into the user partition
- 2: read data from the user partition
<partition>: name of user partition
<offset>: offset of user partition
<length>: data length
<type>: type of user partition
<subtype>: subtype of user partition
<addr>: address of user partition
<size>: size of user partition

Notes¶

Please make sure that you have downloaded at_customize.bin before using this command. For more details, please refer to The Secondary Partitions Table.
When erasing the targeted user partition in its entirety, you can omit the parameters <offset> and <length>. For example, command AT+SYSFLASH=0,"ble_data" can erase the entire “ble_data” user partition. But if you want to keep the two parameters, they have to be 4KB-aligned.
The introduction to partitions is in ESP-IDF Partition Tables.
If the operator is write, wrap return > after the write command, then you can send the data that you want to write. The length should be parameter <length>.
If the operator is write, please make sure that you have already erased this partition.
If the operator is write on a PKI bin, the <length> should be 4 bytes aligned.

Example¶

// read 100 bytes from the "ble_data" partition offset 0.
AT+SYSFLASH=2,"ble_data",0,100

// write 10 bytes to the "ble_data" partition offset 100.
AT+SYSFLASH=1,"ble_data",100,10

// erase 8192 bytes from the "ble_data" partition offset 4096.
AT+SYSFLASH=0,"ble_data",4096,8192

[ESP32 Only] AT+FS: Filesystem Operations¶

Set Command¶

Command:

AT+FS=<type>,<operation>,<filename>,<offset>,<length>

Response:

OK

Parameters¶

<type>: only FATFS is currently supported.
- 0: FATFS
<operation>:
- 0: delete file.
- 1: write file.
- 2: read file.
- 3: query the size of the file.
- 4: list files in a specific directory. Only root directory is currently supported.
<offset>: apply to writing and reading operations only.
<length>: data length, applying to writing and reading operations only.

Notes¶

Please make sure that you have downloaded at_customize.bin before using this command. For more details, refer to ESP-IDF Partition Tables and The Secondary Partitions Table.
If the length of the read data is greater than the actual file length, only the actual data length of the file will be returned.
If the operator is write, wrap return > after the write command, then you can send the data that you want to write. The length should be parameter <length>.

Example¶

// delete a file.
AT+FS=0,0,"filename"

// write 10 bytes to offset 100 of a file.
AT+FS=0,1,"filename",100,10

// read 100 bytes from offset 0 of a file.
AT+FS=0,2,"filename",0,100

// list all files in the root directory.
AT+FS=0,4,"."

AT+RFPOWER: Query/Set RF TX Power¶

Query Command¶

Function:

Query the RF TX Power.

Command:

AT+RFPOWER?

Response:

+RFPOWER:<wifi_power>,<ble_adv_power>,<ble_scan_power>,<ble_conn_power>
OK

Set Command¶

Command:

AT+RFPOWER=<wifi_power>[,<ble_adv_power>,<ble_scan_power>,<ble_conn_power>]

Response:

OK

Parameters¶

<wifi_power>: the unit is 0.25 dBm. For example, if you set the value to 78, the actual maximum RF Power value is 78 * 0.25 dBm = 19.5 dBm. After you configure it, please confirm the actual value by entering the command AT+RFPOWER?.
- For ESP32 and ESP32-S2 devices, the range is [40,78]:
  
  set value
  
  actual value
  
  actual dBm
  
  [34,43]
  
  34
  
  8.5
  
  [44,51]
  
  44
  
  11
  
  [52,55]
  
  52
  
  13
  
  [56,59]
  
  56
  
  14
  
  [60,65]
  
  60
  
  15
  
  [66,71]
  
  66
  
  16.5
  
  [72,77]
  
  72
  
  18
  
  78
  
  78
  
  19.5
- For ESP32-C3 devices, the range is [40,84]:
  
  set value
  
  actual value
  
  actual dBm
  
  [40,80]
  
  <set value>
  
  <set value> * 0.25
  
  [81,84]
  
  80
  
  20
- For ESP8266 devices, the range is [40,82]:
  
  set value
  
  actual value
  
  actual dBm
  
  [40,47]
  
  32
  
  8
  
  [48,55]
  
  48
  
  12
  
  [56,63]
  
  56
  
  14
  
  [64,67]
  
  64
  
  16
  
  [68,73]
  
  68
  
  17
  
  [74,77]
  
  74
  
  18.5
  
  [78,81]
  
  78
  
  19.5
  
  82
  
  82
  
  20.5
<ble_adv_power>: RF TX Power of Bluetooth LE advertising. Range: [0,7].
- 0: 7 dBm
- 1: 4 dBm
- 2: 1 dBm
- 3: -2 dBm
- 4: -5 dBm
- 5: -8 dBm
- 6: -11 dBm
- 7: -14 dBm
<ble_scan_power>: RF TX Power of Bluetooth LE scanning. Range: [0,7]: the parameters are the same as <ble_adv_power>.
<ble_conn_power>: RF TX Power of Bluetooth LE connecting. Range: [0,7]: the same as <ble_adv_power>.

Note¶

Since the RF TX Power is actually divided into several levels, and each level has its own value range, the wifi_power value queried by the esp_wifi_get_max_tx_power may differ from the value set by esp_wifi_set_max_tx_power and is no larger than the set value.

AT+SYSROLLBACK: Roll Back to the Previous Firmware¶

Execute Command¶

Command:

AT+SYSROLLBACK

Response:

OK

Note¶

This command will not upgrade via OTA. It only rolls back to the firmware which is in the other OTA partition.

AT+SYSTIMESTAMP: Query/Set Local Time Stamp¶

Query Command¶

Function:

Query the time stamp.

Command:

AT+SYSTIMESTAMP?

Response:

+SYSTIMESTAMP:<Unix_timestamp>
OK

Set Command¶

Function:

Set local time stamp. It will be the same as SNTP time when the SNTP time is updated.

Command:

AT+SYSTIMESTAMP=<Unix_timestamp>

Response:

OK

Parameter¶

<Unix-timestamp>: Unix timestamp. Unit: second.

Example¶

AT+SYSTIMESTAMP=1565853509    //2019-08-15 15:18:29

AT+SYSLOG: Enable or Disable the AT Error Code Prompt¶

Query Command¶

Function:

Query whether the AT error code prompt is enabled or not.

Command:

AT+SYSLOG?

Response:

+SYSLOG:<status>

OK

Set Command¶

Function:

Enable or disable the AT error code prompt.

Command:

AT+SYSLOG=<status>

Response:

OK

Parameter¶

<status>: enable or disable
- 0: disable
- 1: enable

Example¶

// enable AT error code prompt
AT+SYSLOG=1

OK
AT+FAKE
ERR CODE:0x01090000

ERROR

// disable AT error code prompt
AT+SYSLOG=0

OK
AT+FAKE
// No `ERR CODE:0x01090000`

ERROR

The error code is a 32-bit hexadecimal value and defined as follows:

category	subcategory	extension
bit32 ~ bit24	bit23 ~ bit16	bit15 ~ bit0

category: stationary value 0x01.

subcategory: error type.

Subcategory of Error Code¶
Error Type	Error Code	Description
ESP_AT_SUB_OK	0x00	OK
ESP_AT_SUB_COMMON_ERROR	0x01	reserved
ESP_AT_SUB_NO_TERMINATOR	0x02	terminator character not found (“rn” expected)
ESP_AT_SUB_NO_AT	0x03	Starting AT not found (or at, At or aT entered)
ESP_AT_SUB_PARA_LENGTH_MISMATCH	0x04	parameter length mismatch
ESP_AT_SUB_PARA_TYPE_MISMATCH	0x05	parameter type mismatch
ESP_AT_SUB_PARA_NUM_MISMATCH	0x06	parameter number mismatch
ESP_AT_SUB_PARA_INVALID	0x07	the parameter is invalid
ESP_AT_SUB_PARA_PARSE_FAIL	0x08	parse parameter fail
ESP_AT_SUB_UNSUPPORT_CMD	0x09	the command is not supported
ESP_AT_SUB_CMD_EXEC_FAIL	0x0A	the command execution failed
ESP_AT_SUB_CMD_PROCESSING	0x0B	processing of previous command is in progress
ESP_AT_SUB_CMD_OP_ERROR	0x0C	the command operation type is error

extension: error extension information. There are different extensions for different subcategory. For more information, please see the components/at/include/esp_at.h.

For example, the error code ERR CODE:0x01090000 means the command is not supported.

AT+SLEEPWKCFG: Set the Light-sleep Wakeup Source and Awake GPIO¶

Set Command¶

Command:

AT+SLEEPWKCFG=<wakeup source>,<param1>[,<param2>]

Response:

OK

Parameters¶

<wakeup source>:
- 0: reserved, not supported now.
- 1: reserved, not supported now.
- 2: wakeup by GPIO.
<param1>:
- If the wakeup source is a timer, it means the time before wakeup. Unit: millisecond.
- If the wakeup source is GPIO, it means the GPIO number.
<param2>:
- If the wakeup source is GPIO, it means the wakeup level:
- 0: low level.
- 1: high level.

Note¶

GPIO16 as the RTC IO can not be set as GPIO wakeup source on ESP8266 platform for light sleep.

Example¶

// GPIO12 wakeup, low level
AT+SLEEPWKCFG=2,12,0

AT+SYSSTORE: Query/Set Parameter Store Mode¶

Query Command¶

Function:

Query the AT parameter store mode.

Command:

AT+SYSSTORE?

Response:

+SYSSTORE:<store_mode>

OK

Set Command¶

Command:

AT+SYSSTORE=<store_mode>

Response:

OK

Parameter¶

<store_mode>:
- 0: command configuration is not stored into flash.
- 1: command configuration is stored into flash. (Default)

Note¶

This command affects set commands only. Query commands are always fetched from RAM.
Affected commands:

Examples¶

AT+SYSSTORE=0
AT+CWMODE=1  // Not stored into flash
AT+CWJAP="test","1234567890" // Not stored into flash

AT+SYSSTORE=1
AT+CWMODE=3  // Stored into flash
AT+CWJAP="test","1234567890" // Stored into flash

AT+SYSREG: Read/Write the Register¶

Set Command¶

Command:

AT+SYSREG=<direct>,<address>[,<write value>]

Response:

+SYSREG:<read value>    // Only in read mode
OK

Parameters¶

<direct>: read or write register.
- 0: read register.
- 1: write register.
<address>: (uint32) register address. You can refer to Technical Reference Manuals.
<write value>: (uint32) write value (only in write mode).

Note¶

AT does not check address. Make sure that the registers you are operating on are valid.

Example¶

// Enable ESP32-S2 IO33 output, 0x3F40402C means base address 0x3F404000 add relative address 0x2C (GPIO_ENABLE1_REG)
AT+SYSREG=1,0x3F40402C,0x2

// ESP32-S2 IO33 output high
AT+SYSREG=1,0x3F404010,0x2

// ESP32-S2 IO33 output low
AT+SYSREG=1,0x3F404010,0x0

[ESP32-S2 Only] AT+SYSTEMP: Read ESP32-S2 Internal Temperature¶

Query Command¶

Command:

AT+SYSTEMP?

Response:

+SYSTEMP:<temperature>
OK

Parameter¶

<temperature>: the measured output value. Unit: Celsius.

Note¶

Measure range: -10℃ ~ 80℃. Error < 1℃.

Example¶

AT+SYSTEMP?
+SYSTEMP:21.59
OK

Wi-Fi AT Commands¶

[中文]

AT+CWMODE: Set the Wi-Fi mode (Station/SoftAP/Station+SoftAP).
AT+CWSTATE: Query the Wi-Fi state and Wi-Fi information.
AT+CWJAP: Connect to an AP.
AT+CWRECONNCFG: Query/Set the Wi-Fi reconnecting configuration.
AT+CWLAPOPT: Set the configuration for the command AT+CWLAP.
AT+CWLAP: List available APs.
AT+CWQAP: Disconnect from an AP.
AT+CWSAP: Query/Set the configuration of an ESP SoftAP.
AT+CWLIF: Obtain IP address of the station that connects to an ESP SoftAP.
AT+CWQIF: Disconnect stations from an ESP SoftAP.
AT+CWDHCP: Enable/disable DHCP.
AT+CWDHCPS: Query/Set the IP addresses allocated by an ESP SoftAP DHCP server.
AT+CWAUTOCONN: Connect to an AP automatically when powered on.
AT+CWAPPROTO: Query/Set the 802.11 b/g/n protocol standard of SoftAP mode.
AT+CWSTAPROTO: Query/Set the 802.11 b/g/n protocol standard of station mode.
AT+CIPSTAMAC: Query/Set the MAC address of an ESP station.
AT+CIPAPMAC: Query/Set the MAC address of an ESP SoftAP.
AT+CIPSTA: Query/Set the IP address of an ESP station.
AT+CIPAP: Query/Set the IP address of an ESP SoftAP.
AT+CWSTARTSMART: Start SmartConfig.
AT+CWSTOPSMART: Stop SmartConfig.
AT+WPS: Enable the WPS function.
AT+MDNS: Configure the mDNS function.
[ESP32 Only] AT+CWJEAP: Connect to a WPA2 Enterprise AP.
AT+CWHOSTNAME: Query/Set the host name of an ESP station.
AT+CWCOUNTRY: Query/Set the Wi-Fi Country Code.

AT+CWMODE: Query/Set the Wi-Fi Mode (Station/SoftAP/Station+SoftAP)¶

Query Command¶

Function:

Query the Wi-Fi mode of ESP devices.

Command:

AT+CWMODE?

Response:

+CWMODE:<mode>
OK

Set Command¶

Function:

Set the Wi-Fi mode of ESP devices.

Command:

AT+CWMODE=<mode>[,<auto_connect>]

Response:

OK

Parameters¶

<mode>:
- 0: Null mode. Wi-Fi RF will be disabled.
- 1: Station mode.
- 2: SoftAP mode.
- 3: SoftAP+Station mode.
<auto_connect>: Enable or disable automatic connection to an AP when you change the mode of the ESP device from the SoftAP mode or null mode to the station mode or the SoftAP+Station mode. Default: 1. If you omit the parameter, the default value will be used, i.e. automatically connecting to an AP.
- 0: The ESP device will not automatically connect to an AP.
- 1: The ESP device will automatically connect to an AP if the configuration to connect to the AP has already been saved in flash before.

Note¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.

Example¶

AT+CWMODE=3

AT+CWSTATE: Query the Wi-Fi state and Wi-Fi information¶

Query Command¶

Function:

Query the Wi-Fi state and Wi-Fi information of ESP devices.

Command:

AT+CWSTATE?

Response:

+CWSTATE:<state>,<"ssid">

OK

Parameters¶

<state>: current Wi-Fi state.
- 0: ESP station has not started any Wi-Fi connection.
- 1: ESP station has connected to an AP, but does not get an IPv4 address yet.
- 2: ESP station has connected to an AP, and got an IPv4 address.
- 3: ESP station is in Wi-Fi connecting or reconnecting state.
- 4: ESP station is in Wi-Fi disconnected state.
<”ssid”>: the SSID of the target AP.

Note¶

When ESP station is not connected to an AP, it is recommended to use this command to query Wi-Fi information; after ESP station is connected to an AP, it is recommended to use AT+CWJAP to query Wi-Fi information.

AT+CWJAP: Connect to an AP¶

Query Command¶

Function:

Query the AP to which the ESP Station is already connected.

Command:

AT+CWJAP?

Response:

+CWJAP:<ssid>,<bssid>,<channel>,<rssi>,<pci_en>,<reconn_interval>,<listen_interval>,<scan_mode>,<pmf>
OK

Set Command¶

Function:

Connect an ESP station to a targeted AP.

Command:

AT+CWJAP=[<ssid>],[<pwd>][,<bssid>][,<pci_en>][,<reconn_interval>][,<listen_interval>][,<scan_mode>][,<jap_timeout>][,<pmf>]

Response:

WIFI CONNECTED
WIFI GOT IP

OK
[WIFI GOT IPv6 LL]
[WIFI GOT IPv6 GL]

or

+CWJAP:<error code>
ERROR

Execute Command¶

Function:

Connect an ESP station to a targeted AP with last Wi-Fi configuration.

Command:

AT+CWJAP

Response:

WIFI CONNECTED
WIFI GOT IP

OK
[WIFI GOT IPv6 LL]
[WIFI GOT IPv6 GL]

or

+CWJAP:<error code>
ERROR

Parameters¶

<ssid>: the SSID of the target AP.
- Escape character syntax is needed if SSID or password contains special characters, such ,, ", or \\.
<pwd>: password, MAX: 64-byte ASCII.
<bssid>: the MAC address of the target AP. It cannot be omitted when multiple APs have the same SSID.
<channel>: channel.
<rssi>: signal strength.
<pci_en>: PCI Authentication.
- 0: The ESP station will connect APs with all encryption methods, including OPEN and WEP.
- 1: The ESP station will connect APs with all encryption methods, except OPEN and WEP.
<reconn_interval>: the interval between Wi-Fi reconnections. Unit: second. Default: 1. Maximum: 7200.
- 0: The ESP station will not reconnect to the AP when disconnected.
- [1,7200]: The ESP station will reconnect to the AP at the specified interval when disconnected.
<listen_interval>: the interval of listening to the AP’s beacon. Unit: AP beacon intervals. Default: 3. Range: [1,100].
<scan_mode>:
- 0: fast scan. It will end after finding the targeted AP. The ESP station will connect to the first scanned AP.
- 1: all-channel scan. It will end after all the channels are scanned. The device will connect to the scanned AP with the strongest signal.
<jap_timeout>: maximum timeout for AT+CWJAP command. Unit: second. Default: 15. Range: [3,600].
<pmf>: Protected Management Frames. Default: 0.
- 0 means disable PMF.
- bit 0: PMF capable, advertizes support for protected management frame. Device will prefer to connect in PMF mode if other device also advertizes PMF capability.
- bit 1: PMF required, advertizes that protected management frame is required. Device will not associate to non-PMF capable devices.
<error code>: (for reference only)
- 1: connection timeout.
- 2: wrong password.
- 3: cannot find the target AP.
- 4: connection failed.
- others: unknown error occurred.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
This command requires Station mode to be enabled.
The parameter <reconn_interval> of this command is the same as <interval_second> of the command AT+CWRECONNCFG. Therefore, if you omit <reconn_interval> when running this command, the interval between Wi-Fi reconnections will use the default value 1.
If the <ssid> and <password> parameter are omitted, AT will use the last configuration.
Execute command has the same maximum timeout to setup command. The default value is 15 seconds, but you can change it by setting the parameter <jap_timeout>.
To get an IPv6 address, you need to set AT+CIPV6=1.
Response OK means that the IPv4 network is ready, but not the IPv6 network. At present, ESP-AT is mainly based on IPv4 network, supplemented by IPv6 network.
WIFI GOT IPv6 LL represents that the linklocal IPv6 address has been obtained. This address is calculated locally through EUI-64 and does not require the participation of the AP. Because of the parallel timing, this print may be before or after OK.
WIFI GOT IPv6 GL represents that the global IPv6 address has been obtained. This address is combined by the prefix issued by AP and the suffix calculated internally, which requires the participation of the AP. Because of the parallel timing, this print may be before or after OK, or it may not be printed because the AP does not support IPv6.

Example¶

// If the target AP's SSID is "abc" and the password is "0123456789", the command should be:
AT+CWJAP="abc","0123456789"

// If the target AP's SSID is "ab\,c" and the password is "0123456789"\", the command should be:
AT+CWJAP="ab\\\,c","0123456789\"\\"

// If multiple APs all have the SSID of "abc", the target AP can be found by BSSID:
AT+CWJAP="abc","0123456789","ca:d7:19:d8:a6:44"

// If esp-at is required that connect to a AP by protected management frame, the command should be:
AT+CWJAP="abc","0123456789",,,,,,,3

AT+CWRECONNCFG: Query/Set the Wi-Fi Reconnecting Configuration¶

Query Command¶

Function:

Query the configuration of Wi-Fi reconnect.

Command:

AT+CWRECONNCFG?

Response:

+CWRECONNCFG:<interval_second>,<repeat_count>
OK

Set Command¶

Function:

Set the configuration of Wi-Fi reconnect.

Command:

AT+CWRECONNCFG=<interval_second>,<repeat_count>

Response:

OK

Parameters¶

<interval_second>: the interval between Wi-Fi reconnections. Unit: second. Default: 0. Maximum: 7200.
- 0: The ESP station will not reconnect to the AP when disconnected.
- [1,7200]: The ESP station will reconnect to the AP at the specified interval when disconnected.
<repeat_count>: the number of attempts the ESP device makes to reconnect to the AP. This parameter only works when the parameter <interval_second> is not 0. Default: 0. Maximum: 1000.
- 0: The ESP station will always try to reconnect to AP.
- [1,1000]: The ESP station will attempt to reconnect to AP for the specified times.

Example¶

// The ESP station tries to reconnect to AP at the interval of one second for 100 times.
AT+CWRECONNCFG=1,100

// The ESP station will not reconnect to AP when disconnected.
AT+CWRECONNCFG=0,0

Notes¶

The parameter <interval_second> of this command is the same as the parameter [<reconn_interval>] of the command AT+CWJAP.
This command works for passive disconnection from APs, Wi-Fi mode switch, and Wi-Fi auto connect after power on.

AT+CWLAPOPT: Set the Configuration for the Command AT+CWLAP ¶

Set Command¶

Command:

AT+CWLAPOPT=<reserved>,<print mask>[,<rssi filter>][,<authmode mask>]

Response:

OK

or

ERROR

Parameters¶

<reserved>: reserved item.
<print mask>: determine whether the following parameters are shown in the result of AT+CWLAP. Default: 0x7FF. If you set them to 1, it means showing the corresponding parameters; if you set them as 0, it means NOT showing the corresponding parameters.
- bit 0: determine whether <ecn> will be shown.
- bit 1: determine whether <ssid> will be shown.
- bit 2: determine whether <rssi> will be shown.
- bit 3: determine whether <mac> will be shown.
- bit 4: determine whether <channel> will be shown.
- bit 5: determine whether <freq_offset> will be shown.
- bit 6: determine whether <freqcal_val> will be shown.
- bit 7: determine whether <pairwise_cipher> will be shown.
- bit 8: determine whether <group_cipher> will be shown.
- bit 9: determine whether <bgn> will be shown.
- bit 10: determine whether <wps> will be shown.
[<rssi filter>]: determine whether the result of the command AT+CWLAP will be filtered according to rssi filter. In other words, the result of the command will NOT show the APs whose signal strength is below rssi filter. Unit: dBm. Default: –100. Range: [–100,40].
[<authmode mask>]: determine whether APs with the following authmodes are shown in the result of AT+CWLAP. Default: 0xFFFF. If you set bit x to 1, the APs with the corresponding authmode will be shown. If you set bit x to 0, the APs with the corresponding authmode will NOT be shown;
- bit 0: determine whether APs with OPEN authmode will be shown.
- bit 1: determine whether APs with WEP authmode will be shown.
- bit 2: determine whether APs with WPA_PSK authmode will be shown.
- bit 3: determine whether APs with WPA2_PSK authmode will be shown.
- bit 4: determine whether APs with WPA_WPA2_PSK authmode will be shown.
- bit 5: determine whether APs with WPA2_ENTERPRISE authmode will be shown.
- bit 6: determine whether APs with WPA3_PSK authmode will be shown.
- bit 7: determine whether AP with WPA2_WPA3_PSK authmode will be shown.
- [ESP32-C3 Only] bit 8: determine whether AP with WAPI_PSK authmode will be shown.

Example¶

// The first parameter is 1, meaning that the result of the command AT+CWLAP will be ordered according to RSSI;
// The second parameter is 31, namely 0x1F, meaning that the corresponding bits of <print mask> are set to 1. All parameters will be shown in the result of AT+CWLAP.
AT+CWLAPOPT=1,31
AT+CWLAP

// Just show the AP which authmode is OPEN
AT+CWLAPOPT=1,31,-100,1
AT+CWLAP

AT+CWLAP: List Available APs¶

Set Command¶

Function:

Query the APs with specified parameters, such as the SSID, MAC address, or channel.

Command:

AT+CWLAP=[<ssid>,<mac>,<channel>,<scan_type>,<scan_time_min>,<scan_time_max>]

Execute Command¶

Function:

List all available APs.

Command:

AT+CWLAP

Response:

+CWLAP:<ecn>,<ssid>,<rssi>,<mac>,<channel>,<freq_offset>,<freqcal_val>,<pairwise_cipher>,<group_cipher>,<bgn>,<wps>
OK

Parameters¶

<ecn>: encryption method.
- 0: OPEN
- 1: WEP
- 2: WPA_PSK
- 3: WPA2_PSK
- 4: WPA_WPA2_PSK
- 5: WPA2_ENTERPRISE
- 6: WPA3_PSK
- 7: WPA2_WPA3_PSK
- [ESP32-C3 Only] 8: WAPI_PSK
<ssid>: string parameter showing SSID of the AP.
<rssi>: signal strength.
<mac>: string parameter showing MAC address of the AP.
<channel>: channel.
<scan_type>: Wi-Fi scan type:
- 0: active scan
- 1: passive scan
<scan_time_min>: the minimum active scan time per channel. Unit: millisecond. Range [0,1500]. If the scan type is passive, this parameter is invalid.
<scan_time_max>: the maximum active scan time per channel. Unit: millisecond. Range [0,1500]. If this parameter is 0, the firmware will use the default time: 120 ms for active scan; 360 ms for passive scan.
<freq_offset>: frequency offset (reserved item).
<freqcal_val>: frequency calibration value (reserved item).
<pairwise_cipher>: pairwise cipher type.
- 0: None
- 1: WEP40
- 2: WEP104
- 3: TKIP
- 4: CCMP
- 5: TKIP and CCMP
- 6: AES-CMAC-128
- 7: Unknown
<group_cipher>: group cipher type, same enumerated value to <pairwise_cipher>.
<bgn>: 802.11 b/g/n. If the corresponding bit is 1, the corresponding mode is enabled; if the corresponding bit is 0, the corresponding mode is disabled.
- bit 0: bit to identify if 802.11b mode is enabled or not
- bit 1: bit to identify if 802.11g mode is enabled or not
- bit 2: bit to identify if 802.11n mode is enabled or not
<wps>: wps flag.
- 0: WPS disabled
- 1: WPS enabled

Note¶

For ESP8266 devices, <scan_time_min> and <scan_time_max> must be set to the same value. If these two parameters are omitted or both are set to 0 or the values are different, the firmware will use the default time: 120 ms for active scan; 360 ms for passive scan.

Example¶

AT+CWLAP="Wi-Fi","ca:d7:19:d8:a6:44",6,0,400,1000

// Search for APs with a designated SSID:
AT+CWLAP="Wi-Fi"

AT+CWQAP: Disconnect from an AP¶

Execute Command¶

Command:

AT+CWQAP

Response:

OK

AT+CWSAP: Query/Set the configuration of an ESP SoftAP¶

Query Command¶

Function:

Query the configuration parameters of an ESP SoftAP.

Command:

AT+CWSAP?

Response:

+CWSAP:<ssid>,<pwd>,<channel>,<ecn>,<max conn>,<ssid hidden>
OK

Set Command¶

Function:

Set the configuration of an ESP SoftAP.

Command:

AT+CWSAP=<ssid>,<pwd>,<chl>,<ecn>[,<max conn>][,<ssid hidden>]

Response:

OK

Parameters¶

<ssid>: string parameter showing SSID of the AP.
<pwd>: string parameter showing the password. Length: 8 ~ 64 bytes ASCII.
<channel>: channel ID.
<ecn>: encryption method; WEP is not supported.
- 0: OPEN
- 2: WPA_PSK
- 3: WPA2_PSK
- 4: WPA_WPA2_PSK
[<max conn>]: maximum number of stations that ESP SoftAP can connect. Range: [1,10].
[<ssid hidden>]:
- 0: broadcasting SSID (default).
- 1: not broadcasting SSID.

Notes¶

This command works only when AT+CWMODE=2 or AT+CWMODE=3.
The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.

Example¶

AT+CWSAP="ESP","1234567890",5,3

AT+CWLIF: Obtain IP Address of the Station That Connects to an ESP SoftAP¶

Execute Command¶

Command:

AT+CWLIF

Response:

+CWLIF:<ip addr>,<mac>

OK

Parameters¶

<ip addr>: IP address of the station that connects to the ESP SoftAP.
<mac>: MAC address of the station that connects to the ESP SoftAP.

Note¶

This command cannot get a static IP. It works only when DHCP of both the ESP SoftAP and the connected station are enabled.

AT+CWQIF: Disconnect Stations from an ESP SoftAP¶

Execute Command¶

Function:

Disconnect all stations that are connected to the ESP SoftAP.

Command:

AT+CWQIF

Response:

OK

Set Command¶

Function:

Disconnect a specific station from the ESP SoftAP.

Command:

AT+CWQIF=<mac>

Response:

OK

Parameter¶

<mac>: MAC address of the station to disconnect.

AT+CWDHCP: Enable/Disable DHCP¶

Query Command¶

Command:

AT+CWDHCP?

Response:

<state>

Set Command¶

Function:

Enable/disable DHCP.

Command:

AT+CWDHCP=<operate>,<mode>

Response:

OK

Parameters¶

<operate>:
- 0: disable
- 1: enable
<mode>:
- Bit0: Station DHCP
- Bit1: SoftAP DHCP
<state>: the status of DHCP
- Bit0:
  - 0: Station DHCP is disabled.
  - 1: Station DHCP is enabled.
- Bit1:
  - 0: SoftAP DHCP is disabled.
  - 1: SoftAP DHCP is enabled.
- Bit2 (ESP32 only):
  - 0: Ethernet DHCP is disabled.
  - 1: Ethernet DHCP is enabled.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
This Set Command correlates with the commands that set static IP, such as AT+CIPSTA and AT+CIPAP:
- If DHCP is enabled, static IP address will be disabled;
- If static IP address is enabled, DHCP will be disabled;
- The last configuration overwrites the previous configuration.

Example¶

// Enable Station DHCP. If the last DHCP mode is 2, the current DHCP mode will be 3.
AT+CWDHCP=1,1

// Disable SoftAP DHCP. If the last DHCP mode is 3, the current DHCP mode will be 1.
AT+CWDHCP=0,2

AT+CWDHCPS: Query/Set the IP Addresses Allocated by an ESP SoftAP DHCP Server¶

Query Command¶

Command:

AT+CWDHCPS?

Response:

+CWDHCPS=<lease time>,<start IP>,<end IP>
OK

Set Command¶

Function:

Set the IP address range of the ESP SoftAP DHCP server.

Command:

AT+CWDHCPS=<enable>,<lease time>,<start IP>,<end IP>

Response:

OK

Parameters¶

<enable>:
- 1: Enable DHCP server settings. The parameters below have to be set.
- 0: Disable DHCP server settings and use the default IP address range.
<lease time>: lease time. Unit: minute. Range [1,2880].
<start IP>: start IP address of the IP address range that can be obtained from ESP SoftAP DHCP server.
<end IP>: end IP address of the IP address range that can be obtained from ESP SoftAP DHCP server.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
This AT command works only when both SoftAP and DHCP server are enabled for ESP devices.
The IP address should be in the same network segment as the IP address of ESP SoftAP.

Example¶

AT+CWDHCPS=1,3,"192.168.4.10","192.168.4.15"

AT+CWDHCPS=0 // Disable the settings and use the default IP address range.

AT+CWAUTOCONN: Automatically Connect to an AP When Powered on¶

Set Command¶

Command:

AT+CWAUTOCONN=<enable>

Response:

OK

Parameters¶

<enable>:
- 1: Enable automatic connection to an AP when powered on. (Default)
- 0: Disable automatic connection to an AP when powered on.

Note¶

The configuration changes will be saved in the NVS area.

Example¶

AT+CWAUTOCONN=1

AT+CWAPPROTO: Query/Set the 802.11 b/g/n Protocol Standard of SoftAP Mode¶

Query Command¶

Command:

AT+CWAPPROTO?

Response:

+CWAPPROTO=<protocol>
OK

Set Command¶

Command:

AT+CWAPPROTO=<protocol>

Response:

OK

Parameters¶

<protocol>:
- bit0: 802.11b protocol standard.
- bit1: 802.11g protocol standard.
- bit2: 802.11n protocol standard.

Note¶

Currently ESP devices only support 802.11b or 802.11bg or 802.11bgn mode.
By default, PHY mode of ESP8266 device is 802.11bg mode, and PHY mode of non ESP8266 device is 802.11bgn mode.

AT+CWSTAPROTO: Query/Set the 802.11 b/g/n Protocol Standard of Station Mode¶

Query Command¶

Command:

AT+CWSTAPROTO?

Response:

+CWSTAPROTO=<protocol>
OK

Set Command¶

Command:

AT+CWSTAPROTO=<protocol>

Response:

OK

Parameters¶

<protocol>:
- bit0: 802.11b protocol standard.
- bit1: 802.11g protocol standard.
- bit2: 802.11n protocol standard.

Note¶

Currently ESP devices only support 802.11b or 802.11bg or 802.11bgn mode.
By default, PHY mode of ESP8266 device is 802.11bg mode, and PHY mode of non ESP8266 device is 802.11bgn mode.

AT+CIPSTAMAC: Query/Set the MAC Address of an ESP Station¶

Query Command¶

Function:

Query the MAC address of the ESP Station.

Command:

AT+CIPSTAMAC?

Response:

+CIPSTAMAC:<mac>
OK

Set Command¶

Function:

Set the MAC address of an ESP station.

Command:

AT+CIPSTAMAC=<mac>

Response:

OK

Parameters¶

<mac>: string parameter showing MAC address of an ESP station.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The MAC address of ESP SoftAP is different from that of the ESP Station. Please make sure that you do not set the same MAC address for both of them.
Bit 0 of the ESP MAC address CANNOT be 1. For example, a MAC address can be “1a:…” but not “15:…”.
FF:FF:FF:FF:FF:FF and 00:00:00:00:00:00 are invalid MAC address and cannot be set.

Example¶

AT+CIPSTAMAC="1a:fe:35:98:d3:7b"

AT+CIPAPMAC: Query/Set the MAC Address of an ESP SoftAP¶

Query Command¶

Function:

Query the MAC address of the ESP SoftAP.

Command:

AT+CIPAPMAC?

Response:

+CIPAPMAC:<mac>
OK

Set Command¶

Function:

Set the MAC address of the ESP SoftAP.

Command:

AT+CIPAPMAC=<mac>

Response:

OK

Parameters¶

<mac>: string parameter showing MAC address of the ESP SoftAP.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The MAC address of ESP SoftAP is different from that of the ESP station. Please make sure that you do not set the same MAC address for both of them.
Bit 0 of the ESP MAC address CANNOT be 1. For example, a MAC address can be “18:…” but not “15:…”.
FF:FF:FF:FF:FF:FF and 00:00:00:00:00:00 are invalid MAC and cannot be set.

Example¶

AT+CIPAPMAC="18:fe:35:98:d3:7b"

AT+CIPSTA: Query/Set the IP Address of an ESP Station¶

Query Command¶

Function:

Query the IP address of the ESP Station.

Command:

AT+CIPSTA?

Response:

+CIPSTA:ip:<"ip">
+CIPSTA:gateway:<"gateway">
+CIPSTA:netmask:<"netmask">
+CIPSTA:ip6ll:<"ipv6 addr">
+CIPSTA:ip6gl:<"ipv6 addr">

OK

Set Command¶

Function:

Set the IPv4 address of the ESP station.

Command:

AT+CIPSTA=<"ip">[,<"gateway">,<"netmask">]

Response:

OK

Parameters¶

<”ip”>: string parameter showing the IPv4 address of the ESP station.
<”gateway”>: gateway.
<”netmask”>: netmask.
<”ipv6 addr”>: string parameter showing the IPv6 address of the ESP station.

Notes¶

For the query command, only when the ESP station is connected to an AP or the static IP address is configured can its IP address be queried.
The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The Set Command correlates with the commands that set DHCP, such as AT+CWDHCP.
- If static IP address is enabled, DHCP will be disabled;
- If DHCP is enabled, static IP address will be disabled;
- The last configuration overwrites the previous configuration.

Example¶

AT+CIPSTA="192.168.6.100","192.168.6.1","255.255.255.0"

AT+CIPAP: Query/Set the IP Address of an ESP SoftAP¶

Query Command¶

Function:

Query the IP address of the ESP SoftAP.

Command:

AT+CIPAP?

Response:

+CIPAP:ip:<"ip">
+CIPAP:gateway:<"gateway">
+CIPAP:netmask:<"netmask">
+CIPAP:ip6ll:<"ipv6 addr">
+CIPAP:ip6gl:<"ipv6 addr">

OK

Set Command¶

Function:

Set the IPv4 address of the ESP SoftAP.

Command:

AT+CIPAP=<"ip">[,<"gateway">,<"netmask">]

Response:

OK

Parameters¶

<”ip”>: string parameter showing the IPv4 address of the ESP SoftAP.
<”gateway”>: gateway.
<”netmask”>: netmask.
<”ipv6 addr”>: string parameter showing the IPv6 address of the ESP SoftAP.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The set command correlates with the commands that set DHCP, such as AT+CWDHCP.
- If static IP address is enabled, DHCP will be disabled;
- If DHCP is enabled, static IP address will be disabled;
- The last configuration overwrites the previous configuration.

Example¶

AT+CIPAP="192.168.5.1","192.168.5.1","255.255.255.0"

AT+CWSTARTSMART: Start SmartConfig¶

Execute Command¶

Function:

Start SmartConfig of the type ESP-TOUCH+AirKiss.

Command:

AT+CWSTARTSMART

Set Command¶

Function:

Start SmartConfig of a designated type.

Command:

AT+CWSTARTSMART=<type>[,<auth floor>]

Response:

OK

Parameters¶

<type>:
- 1: ESP-TOUCH
- 2: AirKiss
- 3: ESP-TOUCH+AirKiss
<auth floor>: Wi-Fi authentication mode floor. ESP-AT will not connect to the AP whose authmode is lower than this floor.
- 0: OPEN (Default)
- 1: WEP
- 2: WPA_PSK
- 3: WPA2_PSK
- 4: WPA_WPA2_PSK
- 5: WPA2_ENTERPRISE
- 6: WPA3_PSK
- 7: WPA2_WPA3_PSK

Notes¶

For more details on SmartConfig, please see ESP-TOUCH User Guide.
SmartConfig is only available in the ESP station mode.
The message Smart get Wi-Fi info means that SmartConfig has successfully acquired the AP information. ESP device will try to connect to the target AP.
Message Smartconfig connected Wi-Fi is printed if the connection is successful.
When AT returns Smartconfig connected Wi-Fi, it is recommended to delay more than 6 seconds before executing AT+CWSTOPSMART because the ESP device needs to synchronize the SmartConfig results to the mobile phone.
Use command AT+CWSTOPSMART to stop SmartConfig before running other commands. Please make sure that you do not execute other commands during SmartConfig.

Example¶

AT+CWMODE=1
AT+CWSTARTSMART

AT+CWSTOPSMART: Stop SmartConfig¶

Execute Command¶

Command:

AT+CWSTOPSMART

Response:

OK

Note¶

Irrespective of whether SmartConfig succeeds or not, please always call AT+CWSTOPSMART before executing any other AT commands to release the internal memory taken up by SmartConfig.

Example¶

AT+CWMODE=1
AT+CWSTARTSMART
AT+CWSTOPSMART

AT+WPS: Enable the WPS Function¶

Set Command¶

Command:

AT+WPS=<enable>[,<auth floor>]

Response:

OK

Parameters¶

<enable>:
- 1: Enable WPS (Wi-Fi Protected Setup) that uses PBC (Push Button Configuration) mode.
- 0: Disable WPS that uses PBC mode.
<auth floor>: Wi-Fi authentication mode floor. ESP-AT will not connect to the AP whose authmode is lower than this floor.
- 0: OPEN (Default)
- 1: WEP
- 2: WPA_PSK
- 3: WPA2_PSK
- 4: WPA_WPA2_PSK
- 5: WPA2_ENTERPRISE
- 6: WPA3_PSK
- 7: WPA2_WPA3_PSK

Notes¶

WPS can only be used when the ESP station is enabled.
WPS does not support WEP (Wired-Equivalent Privacy) encryption.

Example¶

AT+CWMODE=1
AT+WPS=1

AT+MDNS: Configure the mDNS Function¶

Set Command¶

Command:

AT+MDNS=<enable>[,<hostname>,<service_name>,<port>]

Response:

OK

Parameters¶

<enable>:
- 1: Enable the mDNS function. The following three parameters need to be set.
- 0: Disable the mDNS function. The following three parameters does not need to be set.
<hostname>: mDNS host name.
<service_name>: mDNS service name.
<port>: mDNS port.

Example¶

AT+MDNS=1,"espressif","_iot",8080
AT+MDNS=0

[ESP32 Only] AT+CWJEAP: Connect to a WPA2 Enterprise AP¶

Query Command¶

Function:

Query the configuration information of the Enterprise AP to which the ESP station is already connected.

Command:

AT+CWJEAP?

Response:

+CWJEAP:<ssid>,<method>,<identity>,<username>,<password>,<security>
OK

Set Command¶

Function:

Connect to the targeted Enterprise AP.

Command:

AT+CWJEAP=<ssid>,<method>,<identity>,<username>,<password>,<security>[,<jeap_timeout>]

Response:

OK

or

+CWJEAP:Timeout
ERROR

Parameters¶

<ssid>: the SSID of the Enterprise AP.
- Escape character syntax is needed if SSID or password contains any special characters, such as ,, ", or \\.
<method>: WPA2 Enterprise authentication method.
- 0: EAP-TLS.
- 1: EAP-PEAP.
- 2: EAP-TTLS.
<identity>: identity for phase 1. String limited to 1 ~ 32.
<username>: username for phase 2. Range: 1 ~ 32 bytes. For the EAP-PEAP and EAP-TTLS method, you must set this parameter. For the EAP-TLS method, you don’t need to.
<password>: password for phase 2. Range: 1 ~ 32 bytes. For the EAP-PEAP and EAP-TTLS method, you must set this parameter. For the EAP-TLS method, you don’t need to.
<security>:
- Bit0: Client certificate.
- Bit1: Server certificate.
[<jeap_timeout>]: maximum timeout for AT+CWJEAP command. Unit: second. Default: 15. Range: [3,600].

Example¶

// Connect to EAP-TLS mode Enterprise AP, set identity, verify server certificate and load client certificate
AT+CWJEAP="dlink11111",0,"example@espressif.com",,,3

// Connect to EAP-PEAP mode Enterprise AP, set identity, username and password, not verify server certificate and not load client certificate
AT+CWJEAP="dlink11111",1,"example@espressif.com","espressif","test11",0

Error Code:

The WPA2 Enterprise error code will be prompt as ERR CODE:0x<%08x>.

AT_EAP_MALLOC_FAILED	0x8001
AT_EAP_GET_NVS_CONFIG_FAILED	0x8002
AT_EAP_CONN_FAILED	0x8003
AT_EAP_SET_WIFI_CONFIG_FAILED	0x8004
AT_EAP_SET_IDENTITY_FAILED	0x8005
AT_EAP_SET_USERNAME_FAILED	0x8006
AT_EAP_SET_PASSWORD_FAILED	0x8007
AT_EAP_GET_CA_LEN_FAILED	0x8008
AT_EAP_READ_CA_FAILED	0x8009
AT_EAP_SET_CA_FAILED	0x800A
AT_EAP_GET_CERT_LEN_FAILED	0x800B
AT_EAP_READ_CERT_FAILED	0x800C
AT_EAP_GET_KEY_LEN_FAILED	0x800D
AT_EAP_READ_KEY_FAILED	0x800E
AT_EAP_SET_CERT_KEY_FAILED	0x800F
AT_EAP_ENABLE_FAILED	0x8010
AT_EAP_ALREADY_CONNECTED	0x8011
AT_EAP_GET_SSID_FAILED	0x8012
AT_EAP_SSID_NULL	0x8013
AT_EAP_SSID_LEN_ERROR	0x8014
AT_EAP_GET_METHOD_FAILED	0x8015
AT_EAP_CONN_TIMEOUT	0x8016
AT_EAP_GET_IDENTITY_FAILED	0x8017
AT_EAP_IDENTITY_LEN_ERROR	0x8018
AT_EAP_GET_USERNAME_FAILED	0x8019
AT_EAP_USERNAME_LEN_ERROR	0x801A
AT_EAP_GET_PASSWORD_FAILED	0x801B
AT_EAP_PASSWORD_LEN_ERROR	0x801C
AT_EAP_GET_SECURITY_FAILED	0x801D
AT_EAP_SECURITY_ERROR	0x801E
AT_EAP_METHOD_SECURITY_UNMATCHED	0x801F
AT_EAP_PARAMETER_COUNTS_ERROR	0x8020
AT_EAP_GET_WIFI_MODE_ERROR	0x8021
AT_EAP_WIFI_MODE_NOT_STA	0x8022
AT_EAP_SET_CONFIG_FAILED	0x8023
AT_EAP_METHOD_ERROR	0x8024

Note¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
This command requires Station mode to be active.
TLS mode will use client certificate. Please make sure it is enabled.

AT+CWHOSTNAME: Query/Set the Host Name of an ESP Station¶

Query Command¶

Function:

Query the host name of ESP Station.

Command:

AT+CWHOSTNAME?

Response:

+CWHOSTNAME:<hostname>

OK

Set Command¶

Function:

Set the host name of ESP Station.

Command:

AT+CWHOSTNAME=<hostname>

Response:

OK

If the Station mode is not enabled, the command will return:

ERROR

Parameters¶

<hostname>: the host name of the ESP Station. Maximum length: 32 bytes.

Note¶

The configuration changes are not saved in the flash.

Example¶

AT+CWMODE=3
AT+CWHOSTNAME="my_test"

AT+CWCOUNTRY: Query/Set the Wi-Fi Country Code¶

Query Command¶

Function:

Query Wi-Fi country code information.

Command:

AT+CWCOUNTRY?

Response:

+CWCOUNTRY:<country_policy>,<country_code>,<start_channel>,<total_channel_count>

OK

Set Command¶

Function:

Set the Wi-Fi country code information.

Command:

AT+ CWCOUNTRY=<country_policy>,<country_code>,<start_channel>,<total_channel_count>

Response:

OK

Parameters¶

<country_policy>:
- 0: will change the county code to be the same as the AP that the ESP device is connected to.
- 1: the country code will not change, always be the one set by command.
<country_code>: country code. Maximum length: 3 characters.
<start_channel>: the channel number to start. Range: [1,14].
<total_channel_count>: total number of channels.

Note¶

The configuration changes are not saved in the flash.

Example¶

AT+CWMODE=3
AT+CWCOUNTRY=1,"CN",1,13

TCP/IP AT Commands¶

[中文]

AT+CIPV6: Enable/disable the network of Internet Protocol Version 6 (IPv6).
AT+CIPSTATUS: Obtain the TCP/UDP/SSL connection status and information.
AT+CIPDOMAIN: Resolve a Domain Name.
AT+CIPSTART: Establish TCP connection, UDP transmission, or SSL connection.
AT+CIPSTARTEX: Establish TCP connection, UDP transmission, or SSL connection with an automatically assigned ID.
[Passthrough Mode Only] +++: Exit the passthrough mode.
AT+CIPSEND: Send data in the normal transmission mode or Wi-Fi passthrough mode.
AT+CIPSENDEX: Send data in the normal transmission mode in expanded ways.
AT+CIPCLOSE: Close TCP/UDP/SSL connection.
AT+CIFSR: Obtain the local IP address and MAC address.
AT+CIPMUX: Enable/disable the multiple connections mode.
AT+CIPSERVER: Delete/create a TCP/SSL server.
AT+CIPSERVERMAXCONN: Query/Set the maximum connections allowed by a server.
AT+CIPMODE: Query/Set the transmission mode.
AT+SAVETRANSLINK: Set whether to enter Wi-Fi passthrough mode on power-up.
AT+CIPSTO: Query/Set the local TCP Server Timeout.
AT+CIPSNTPCFG: Query/Set the time zone and SNTP server.
AT+CIPSNTPTIME: Query the SNTP time.
AT+CIUPDATE: Upgrade the firmware through Wi-Fi.
AT+CIPDINFO: Set “+IPD” message mode.
AT+CIPSSLCCONF: Query/Set SSL clients.
AT+CIPSSLCCN: Query/Set the Common Name of the SSL client.
AT+CIPSSLCSNI: Query/Set SSL client Server Name Indication (SNI).
AT+CIPSSLCALPN: Query/Set SSL client Application Layer Protocol Negotiation (ALPN).
AT+CIPSSLCPSK: Query/Set SSL client Pre-shared Key (PSK).
AT+CIPRECONNINTV: Query/Set the TCP/UDP/SSL reconnection interval for the Wi-Fi passthrough mode.
AT+CIPRECVMODE: Query/Set socket receiving mode.
AT+CIPRECVDATA: Obtain socket data in passive receiving mode.
AT+CIPRECVLEN: Obtain socket data length in passive receiving mode.
AT+PING: Ping the remote host.
AT+CIPDNS: Query/Set DNS server information.
AT+CIPTCPOPT: Query/Set the socket options.

AT+CIPV6: Enable/disable the network of Internet Protocol Version 6 (IPv6)¶

Query Command¶

Function:

Query whether IPv6 is enabled.

Command:

AT+CIPV6?

Response:

+CIPV6:<enable>

OK

Set Command¶

Function:

Enable/Disable IPv6 network.

Command:

AT+CIPV6=<enable>

Response:

OK

Parameters¶

<enable>: status of IPv6 network. Default: 0.
- 0: disable IPv6 network.
- 1: enable IPv6 network.

Notes¶

You should enable IPv6 network before using IPv6 related upper layer AT commands (TCP/UDP/SSL/PING/DNS based on IPv6 network, also known as TCP6/UDP6/SSL6/PING6/DNS6 or TCPv6/UDPv6/SSLv6/PINGv6/DNSv6).

AT+CIPSTATUS: Obtain the TCP/UDP/SSL Connection Status and Information¶

Execute Command¶

Command:

AT+CIPSTATUS

Response:

STATUS:<stat>
+CIPSTATUS:<link ID>,<"type">,<"remote IP">,<remote port>,<local port>,<tetype>
OK

Parameters¶

<stat>: status of the ESP station interface.
- 0: The ESP station is not initialized.
- 1: The ESP station is initialized, but not started a Wi-Fi connection yet.
- 2: The ESP station is connected to an AP and its IP address is obtained.
- 3: The ESP station has created a TCP/SSL transmission.
- 4: All of the TCP/UDP/SSL connections of the ESP device station are disconnected.
- 5: The ESP station started a Wi-Fi connection, but was not connected to an AP or disconnected from an AP.
<link ID>: ID of the connection (0~4), used for multiple connections.
<”type”>: string parameter showing the type of transmission: “TCP”, “TCPv6”, “UDP”, “UDPv6”, “SSL”, or “SSLv6”.
<”remote IP”>: string parameter showing the remote IPv4 address or IPv6 address.
<remote port>: the remote port number.
<local port>: the local port number.
<tetype>:
- 0: ESP device runs as a client.
- 1: ESP device runs as a server.

AT+CIPDOMAIN: Resolve a Domain Name¶

Set Command¶

Command:

AT+CIPDOMAIN=<"domain name">[,<ip network>]

Response:

+CIPDOMAIN:<"IP address">

OK

Parameter¶

<”domain name”>: the domain name.
<ip network>: preferred IP network. Default: 1.
- 1: preferred resolution of IPv4 address
- 2: resolve IPv4 address only
- 3: resolve IPv6 address only
<”IP address”>: the resolved IPv4 address or IPv6 address.

Example¶

AT+CWMODE=1                       // set the station mode
AT+CWJAP="SSID","password"        // access to the internet
AT+CIPDOMAIN="iot.espressif.cn"   // Domain Name Resolution function

// Domain Name Resolution Function for IPv4 address only
AT+CIPDOMAIN="iot.espressif.cn",2

// Domain Name Resolution Function for IPv6 address only
AT+CIPDOMAIN="ipv6.test-ipv6.com",3

// Domain Name Resolution Function for compatible IP address
AT+CIPDOMAIN="ds.test-ipv6.com",1

AT+CIPSTART: Establish TCP Connection, UDP Transmission, or SSL Connection¶

Establish TCP Connection¶

Set Command¶

Command:

// Single connection (AT+CIPMUX=0):
AT+CIPSTART=<"type">,<"remote host">,<remote port>[,<keep alive>][,<"local IP">]

// Multiple Connections (AT+CIPMUX=1):
AT+CIPSTART=<link ID>,<"type">,<"remote host">,<remote port>[,<keep alive>][,<"local IP">]

Response:

CONNECT

OK

Parameters¶

<link ID>: ID of network connection (0~4), used for multiple connections.
<”type”>: string parameter showing the type of transmission: “TCP”, or “TCPv6”. Default: “TCP”.
<”remote host”>: string parameter showing the IPv4 address or IPv6 address or domain name of remote host.
<remote port>: the remote port number.
<keep alive>: TCP keep-alive interval. Default: 0.
- 0: disable TCP keep-alive function.
- 1 ~ 7200: detection interval. Unit: second.
<”local IP”>: the local IPv4 address or IPv6 address that the connection binds. This parameter is useful when you are using multiple network interfaces or multiple IP addresses. By default, it is disabled. If you want to use it, you should specify it first. Null is also valid.

Notes¶

If you want to establish TCP connection based on IPv6 network, set AT+CIPV6=1 first, and ensure the connected AP by AT+CWJAP supports IPv6 and esp-at got the IPv6 address which you can check it by AT+CIPSTA.
<keep alive> parameter will eventually be configured to the socket option TCP_KEEPIDLE. As for other socket options of keepalive, TCP_KEEPINTVL will use 1 by default, and TCP_KEEPCNT will use 3 by default.

Example¶

AT+CIPSTART="TCP","iot.espressif.cn",8000
AT+CIPSTART="TCP","192.168.101.110",1000
AT+CIPSTART="TCP","192.168.101.110",1000,,"192.168.101.100"
AT+CIPSTART="TCPv6","test-ipv6.com",80
AT+CIPSTART="TCPv6","fe80::860d:8eff:fe9d:cd90",1000,,"fe80::411c:1fdb:22a6:4d24"

// esp-at has obtained an IPv6 global address by AT+CWJAP before
AT+CIPSTART="TCPv6","2404:6800:4005:80b::2004",80,,"240e:3a1:2070:11c0:32ae:a4ff:fe80:65ac"

Establish UDP Transmission¶

Set Command¶

Command:

// Single connection (AT+CIPMUX=0):
AT+CIPSTART=<"type">,<"remote host">,<remote port>[,<local port>,<mode>,<"local IP">]

// Multiple connections (AT+CIPMUX=1):
AT+CIPSTART=<link ID>,<"type">,<"remote host">,<remote port>[,<local port>,<mode>,<"local IP">]

Response:

CONNECT

OK

Parameters¶

<link ID>: ID of network connection (0~4), used for multiple connections.
<”type”>: string parameter showing the type of transmission: “UDP”, or “UDPv6”. Default: “TCP”.
<”remote host”>: string parameter showing the IPv4 address or IPv6 address or domain name of remote host.
<remote port>: remote port number.
<local port>: UDP port of ESP devices.
<mode>: In the UDP Wi-Fi passthrough, the value of this parameter has to be 0.
- 0: After UDP data is received, the parameters <"remote host"> and <remote port> will stay unchanged (default).
- 1: Only the first time that UDP data is received from an IP address and port that are different from the initially set value of parameters <remote host> and <remote port>, will they be changed to the IP address and port of the device that sends the data.
- 2: Each time UDP data is received, the <"remote host"> and <remote port> will be changed to the IP address and port of the device that sends the data.
<”local IP”>: the local IPv4 address or IPv6 address that the connection binds. This parameter is useful when you are using multiple network interfaces or multiple IP addresses. By default, it is disabled. If you want to use it, you should specify it first. Null is also valid.

Notes¶

If the remote host over the UDP is an IPv4 multicast address (224.0.0.0 ~ 239.255.255.255), the ESP device will send and receive the UDPv4 multicast.
If the remote host over the UDP is an IPv4 broadcast address (255.255.255.255), the ESP device will send and receive the UDPv4 broadcast.
If the remote host over the UDP is an IPv6 multicast address (FF00:0:0:0:0:0:0:0 ~ FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF), the ESP device will send and receive the UDP multicast based on IPv6 network.
To use the parameter <mode>, parameter <local port> must be set first.
If you want to establish UDP connection based on IPv6 network, set AT+CIPV6=1 first, and ensure the connected AP by AT+CWJAP supports IPv6 and esp-at got the IPv6 address which you can check it by AT+CIPSTA.

Example¶

// UDP unicast
AT+CIPSTART="UDP","192.168.101.110",1000,1002,2
AT+CIPSTART="UDP","192.168.101.110",1000,,,"192.168.101.100"

// UDP unicast based on IPv6 network
AT+CIPSTART="UDPv6","fe80::32ae:a4ff:fe80:65ac",1000,,,"fe80::5512:f37f:bb03:5d9b"

// UDP multicast based on IPv6 network
AT+CIPSTART="UDPv6","FF02::FC",1000,1002,0

Establish SSL Connection¶

Set Command¶

Command:

AT+CIPSTART=[<link ID>,]<"type">,<"remote host">,<remote port>[,<keep alive>,<"local IP">]

Response:

OK

Parameters¶

<link ID>: ID of network connection (0~4), used for multiple connections.
<”type”>: string parameter showing the type of transmission: “SSL”, or “SSLv6”. Default: “TCP”.
<”remote host”>: string parameter showing the IPv4 address or IPv6 address or domain name of remote host.
<remote port>: the remote port number.
<keep alive>: reserved item for SSL. Default: 0.
<”local IP”>: the local IPv4 address or IPv6 address that the connection binds. This parameter is useful when you are using multiple network interfaces or multiple IP addresses. By default, it is disabled. If you want to use it, you should specify it first. Null is also valid.

Notes¶

The number of SSL connections depends on available memory and the maximum number of connections. For ESP8266 devices, only one SSL connection can be established due to limited memory.
SSL connection needs a large amount of memory. Insufficient memory may cause the system reboot.
If the AT+CIPSTART is based on an SSL connection and the timeout of each packet is 10 s, the total timeout will be much longer depending on the number of handshake packets.
If you want to establish SSL connection based on IPv6 network, set AT+CIPV6=1 first, and ensure the connected AP by AT+CWJAP supports IPv6 and esp-at got the IPv6 address which you can check it by AT+CIPSTA.
<keep alive> parameter will eventually be configured to the socket option TCP_KEEPIDLE. As for other socket options of keepalive, TCP_KEEPINTVL will use 1 by default, and TCP_KEEPCNT will use 3 by default.

Example¶

AT+CIPSTART="SSL","iot.espressif.cn",8443
AT+CIPSTART="SSL","192.168.101.110",1000,,"192.168.101.100"

// esp-at has obtained an IPv6 global address by AT+CWJAP before
AT+CIPSTART="SSLv6","240e:3a1:2070:11c0:6972:6f96:9147:d66d",1000,,"240e:3a1:2070:11c0:55ce:4e19:9649:b75"

AT+CIPSTARTEX: Establish TCP connection, UDP transmission, or SSL connection with an Automatically Assigned ID¶

This command is similar to AT+CIPSTART except that you don’t need to assign an ID by yourself in multiple connections mode (AT+CIPMUX=1). The system will assign an ID to the new connection automatically.

[Passthrough Mode Only] +++: Exit from Passthrough Mode ¶

Special Execute Command¶

Function:

Exit from Passthrough Mode and enter the Passthrough Receiving Mode.

Command:

// Only for passthrough mode
+++

Notes¶

This special execution command consists of three identical + characters (0x2b ASCII), and no CR-LF appends to the command tail.
Make sure there is more than 20 ms interval before the first + character, more than 20 ms interval after the third + character, less than 20 ms interval among the three + characters. Otherwise, the + characters will be sent out as normal passthrough data.
This command returns no reply.

AT+CIPSEND: Send Data in the Normal Transmission Mode or Wi-Fi Passthrough Mode ¶

Set Command¶

Function:

Set the data length to be send in the Normal Transmission Mode.

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSEND=<length>

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSEND=<link ID>,<length>

// Remote host and port can be set for UDP transmission:
AT+CIPSEND=[<link ID>,]<length>[,<"remote host">,<remote port>]

Response:

OK

>

This response indicates that AT is ready for receiving serial data. You should enter the data, and when the data length reaches the <length> value, the transmission of data starts.

If the connection cannot be established or is disrupted during data transmission, the system returns:

ERROR

If data is transmitted successfully, the system returns:

SEND OK

Execute Command¶

Function:

Enter the Wi-Fi Passthrough Mode.

Command:

AT+CIPSEND

Response:

OK
>

or

ERROR

Enter the Wi-Fi Passthrough Mode. The ESP8266 devices can receive 2048 bytes and send 1460 bytes at most each time; the other ESP devices can receive 8192 bytes and send 2920 bytes at most each time. If the length of the currently received data is greater than the maximum number of bytes that can be sent, AT will send the received data immediately; Otherwise, the received data will be sent out within 20 ms. When a single packet containing +++ is received, the ESP device will exit the data sending mode under the Wi-Fi Passthrough Mode. Please wait for at least one second before sending the next AT command.

This command can only be used for single connection in the Wi-Fi Passthrough Mode. For UDP Wi-Fi passthrough, the <mode> parameter has to be 0 when using AT+CIPSTART.

Parameters¶

<link ID>: ID of the connection (0~4), for multiple connections.
<length>: data length. Maximum: 2048 bytes.
<”remote host”>: IPv4 address or IPv6 address or domain name of remote host, can be set in UDP transmission.
<remote port>: the remote port number.

AT+CIPSENDEX: Send Data in the Normal Transmission Mode in Expanded Ways¶

Set Command¶

Function:

Set the data length to be send in Normal Transmission Mode, or use \0 (0x5c, 0x30 ASCII) to trigger data transmission.

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSENDEX=<length>

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSENDEX=<link ID>,<length>

// Remote host and port can be set for UDP transmission:
AT+CIPSENDEX=[<link ID>,]<length>[,<"remote host">,<remote port>]

Response:

OK

>

This response indicates that AT is ready for receiving data. You should enter the data of designated length. When the data length reaches the <length> value, or when the string \0 appears in the data, the transmission starts.

If the connection cannot be established or gets disconnected during transmission, the system returns:

ERROR

If the data are successfully transmitted, the system returns:

SEND OK

Parameters¶

<link ID>: ID of the connection (0~4), for multiple connections.
<length>: data length. Maximum: 2048 bytes.
<”remote host”>: IPv4 address or IPv6 address or domain name of remote host, can be set in UDP transmission.
<remote port>: remote port can be set in UDP transmission.

Notes¶

When the requirement of data length is met, or when the string \0 (0x5c, 0x30 in ASCII) appears, the transmission of data starts. Go back to the normal command mode and wait for the next AT command.
If the data contains the \<any>, it means that drop backslash symbol and only use <any> character.
When sending \0, please use a backslash to escape it as \\0.

AT+CIPCLOSE: Close TCP/UDP/SSL Connection¶

Set Command¶

Function:

Close TCP/UDP/SSL connection in the multiple connections mode.

Command:

AT+CIPCLOSE=<link ID>

Execute Command¶

Function:

Close TCP/UDP/SSL connection in the single connection mode.

AT+CIPCLOSE

Response:

OK

Parameter¶

<link ID>: ID of the connection that you want to close. If you set it to 5, all connections will be closed.

AT+CIFSR: Obtain the Local IP Address and MAC Address¶

Execute Command¶

Command:

AT+CIFSR

Response:

+CIFSR:APIP,<"APIP">
+CIFSR:APIP6LL,<"APIP6LL">
+CIFSR:APIP6GL,<"APIP6GL">
+CIFSR:APMAC,<"APMAC">
+CIFSR:STAIP,<"STAIP">
+CIFSR:STAIP6LL,<"STAIP6LL">
+CIFSR:STAIP6GL,<"STAIP6GL">
+CIFSR:STAMAC,<"STAMAC">
+CIFSR:ETHIP,<"ETHIP">
+CIFSR:ETHIP6LL,<"ETHIP6LL">
+CIFSR:ETHIP6GL,<"ETHIP6GL">
+CIFSR:ETHMAC,<"ETHMAC">

OK

Parameters¶

<”APIP”>: IPv4 address of Wi-Fi softAP interface
<”APIP6LL”>: Linklocal IPv6 address of Wi-Fi softAP interface
<”APIP6GL”>: Global IPv6 address of Wi-Fi softAP interface
<”APMAC”>: MAC address of Wi-Fi softAP interface
<”STAIP”>: IPv4 address of Wi-Fi station interface
<”STAIP6LL”>: Linklocal IPv6 address of Wi-Fi station interface
<”STAIP6GL”>: Global IPv6 address of Wi-Fi station interface
<”STAMAC”>: MAC address of Wi-Fi station interface
<”ETHIP”>: IPv4 address of ethernet interface
<”ETHIP6LL”>: Linklocal IPv6 address of ethernet interface
<”ETHIP6GL”>: Global IPv6 address of ethernet interface
<”ETHMAC”>: MAC address of ethernet interface

Note¶

Only when the ESP device has the valid interface information can you query its IP address and MAC address.

AT+CIPMUX: Enable/disable Multiple Connections¶

Query Command¶

Function:

Query the connection type.

Command:

AT+CIPMUX?

Response:

+CIPMUX:<mode>
OK

Set Command¶

Function:

Set the connection type.

Command:

AT+CIPMUX=<mode>

Response:

OK

Parameter¶

<mode>: connection mode. Default: 0.
- 0: single connection.
- 1: multiple connections.

Notes¶

This mode can only be changed after all connections are disconnected.
If you want to set the multiple connections mode, ESP devices should be in the Normal Transmission Mode (AT+CIPMODE=0).
If you want to set the single connection mode when the TCP/SSL server is running, you should delete the server first. (AT+CIPSERVER=0).

Example¶

AT+CIPMUX=1

AT+CIPSERVER: Delete/create a TCP/SSL Server¶

Query Command¶

Function:

Query the TCP/SSL server status.

Command:

AT+CIPSERVER?

Response:

+CIPSERVER:<mode>[,<port>,<"type">][,<CA enable>]

OK

Set Command¶

Command:

AT+CIPSERVER=<mode>[,<param2>][,<"type">][,<CA enable>]

Response:

OK

Parameters¶

<mode>:
- 0: delete a server.
- 1: create a server.
<param2>: It means differently depending on the parameter <mode>:

If <mode> is 1, <param2> represents the port number. Default: 333.

If <mode> is 0, <param2> represents whether the server closes all connections. Default: 0.

0: shutdown the server and keep existing connections.

1: shutdown the server and close all connections.

<”type”>: server type: “TCP”, “TCPv6”, “SSL”, or “SSLv6”. Default: “TCP”. This parameter is NOT applicable to ESP8266 platform due to memory limitation.
<CA enable>: not applicable to ESP8266 devices.
- 0: disable CA.
- 1: enable CA.

Notes¶

A TCP/SSL server can only be created when multiple connections are activated (AT+CIPMUX=1).
A server monitor will be created automatically when the server is created. Only one server can be created at most.
When a client is connected to the server, it will take up one connection and be assigned an ID.
If you want to create a TCP/SSL server based on IPv6 network, set AT+CIPV6=1 first, and obtain an IPv6 address.

Example¶

// To create a TCP server
AT+CIPMUX=1
AT+CIPSERVER=1,80

// To create an SSL server
AT+CIPMUX=1
AT+CIPSERVER=1,443,"SSL",1

// To create an SSL server based on IPv6 network
AT+CIPMUX=1
AT+CIPSERVER=1,443,"SSLv6",0

// To delete an server and close all clients
AT+CIPSERVER=0,1

AT+CIPSERVERMAXCONN: Query/Set the Maximum Connections Allowed by a Server¶

Query Command¶

Function:

Obtain the maximum number of clients allowed to connect to the TCP/SSL server.

Command:

AT+CIPSERVERMAXCONN?

Response:

+CIPSERVERMAXCONN:<num>
OK

Set Command¶

Function:

Set the maximum number of clients allowed to connect to the TCP/SSL server.

Command:

AT+CIPSERVERMAXCONN=<num>

Response:

OK

Parameter¶

<num>: the maximum number of clients allowed to connect to the TCP/SSL server.

Note¶

You should call the command AT+CIPSERVERMAXCONN=<num> before creating a server.

Example¶

AT+CIPMUX=1
AT+CIPSERVERMAXCONN=2
AT+CIPSERVER=1,80

AT+CIPMODE: Query/Set the Transmission Mode¶

Query Command¶

Function:

Query the transmission mode.

Command:

AT+CIPMODE?

Response:

+CIPMODE:<mode>
OK

Set Command¶

Function:

Set the transmission mode.

Command:

AT+CIPMODE=<mode>

Response:

OK

Parameter¶

<mode>:
- 0: Normal Transmission Mode.
- 1: Wi-Fi Passthrough Receiving Mode, or called transparent receiving transmission, which can only be enabled in TCP single connection mode, UDP mode when the remote host and port do not change, or SSL single connection mode.

Notes¶

The configuration changes will NOT be saved in flash.

Example¶

AT+CIPMODE=1

AT+SAVETRANSLINK: Set Whether to Enter Wi-Fi Passthrough Mode on Power-up¶

For TCP/SSL Single Connection¶

Set Command¶

Command:

AT+SAVETRANSLINK=<mode>,<"remote host">,<remote port>[,<"type">,<keep alive>]

Response:

OK

Parameters¶

<mode>:
- 0: ESP will NOT enter Wi-Fi Passthrough Mode on power-up.
- 1: ESP will enter Wi-Fi Passthrough Mode on power-up.
<”remote host”>: string parameter showing the IPv4 address or IPv6 address or domain name of remote host.
<remote port>: the remote port number.
<”type”>: string parameter showing the type of transmission: “TCP”, “TCPv6”, “SSL”, or “SSLv6”. Default: “TCP”.
<keep alive>: TCP keep-alive interval. Default: 0.
- 0: disable the keep-alive function.
- 1 ~ 7200: detection interval. Unit: second.

Notes¶

This command will save the Wi-Fi Passthrough Mode configuration in the NVS area. If <mode> is set to 1, ESP device will enter the Wi-Fi Passthrough Mode in any subsequent power cycles. The configuration will take effect after ESP reboots.
As long as the remote host and port are valid, the configuration will be saved in flash.
If you want to establish TCP/SSL connection based on IPv6 network, set AT+CIPV6=1 first, and ensure the connected AP by AT+CWJAP supports IPv6 and esp-at got the IPv6 address which you can check it by AT+CIPSTA.

Example¶

AT+SAVETRANSLINK=1,"192.168.6.110",1002,"TCP"
AT+SAVETRANSLINK=1,"www.baidu.com",443,"SSL"
AT+SAVETRANSLINK=1,"240e:3a1:2070:11c0:55ce:4e19:9649:b75",8080,"TCPv6"
AT+SAVETRANSLINK=1,"240e:3a1:2070:11c0:55ce:4e19:9649:b75",8080,"SSLv6"

For UDP Transmission¶

Set Command¶

Command:

AT+SAVETRANSLINK=<mode>,<"remote host">,<remote port>,[<"type">,<local port>]

Response:

OK

Parameters¶

<mode>:
- 0: ESP will NOT enter Wi-Fi Passthrough Mode on power-up.
- 1: ESP will enter Wi-Fi Passthrough Mode on power-up.
<”remote host”>: string parameter showing the IPv4 address or IPv6 address or domain name of remote host.
<remote port>: the remote port number.
<”type”>: string parameter showing the type of transmission: “UDP” or “UDPv6”. Default: “TCP”.
<local port>: local port when UDP Wi-Fi passthrough is enabled on power-up.

Notes¶

This command will save the Wi-Fi Passthrough Mode configuration in the NVS area. If <mode> is set to 1, ESP device will enter the Wi-Fi Passthrough Mode in any subsequent power cycles. The configuration will take effect after ESP reboots.
As long as the remote host and port are valid, the configuration will be saved in flash.
If you want to establish UDP transmission based on IPv6 network, set AT+CIPV6=1 first, and ensure the connected AP by AT+CWJAP supports IPv6 and esp-at got the IPv6 address which you can check it by AT+CIPSTA.

Example¶

AT+SAVETRANSLINK=1,"192.168.6.110",1002,"UDP",1005
AT+SAVETRANSLINK=1,"240e:3a1:2070:11c0:55ce:4e19:9649:b75",8081,"UDPv6",1005

AT+CIPSTO: Query/Set the local TCP/SSL Server Timeout¶

Query Command¶

Function:

Query the local TCP/SSL server timeout.

Command:

AT+CIPSTO?

Response:

+CIPSTO:<time>
OK

Set Command¶

Function:

Set the local TCP/SSL server timeout.

Command:

AT+CIPSTO=<time>

Response:

OK

Parameter¶

<time>: local TCP/SSL server timeout. Unit: second. Range: [0,7200].

Notes¶

When a TCP/SSL client does not communicate with the ESP server within the <time> value, the server will terminate this connection.
If you set <time> to 0, the connection will never timeout. This configuration is not recommended.
When the client initiates a communication with the server within the set time, the timer will restart. After the timeout expires, the client is closed. During the set time, if the server initiate a communication with the client, the timer will not restart. After the timeout expires, the client is closed.

Example¶

AT+CIPMUX=1
AT+CIPSERVER=1,1001
AT+CIPSTO=10

AT+CIPSNTPCFG: Query/Set the Time Zone and the SNTP Server¶

Query Command¶

Command:

AT+CIPSNTPCFG?

Response:

+CIPSNTPCFG:<enable>,<timezone>,<SNTP server1>[,<SNTP server2>,<SNTP server3>]
OK

Set Command¶

Command:

AT+CIPSNTPCFG=<enable>,<timezone>[,<SNTP server1>,<SNTP server2>,<SNTP server3>]

Response:

OK

Parameters¶

<enable>: configure the SNTP server:
- 1: the SNTP server is configured.
- 0: the SNTP server is not configured.
<timezone>: support the following two formats:
- The first format range is [-12,14]. It marks most of the time zones by offset from Coordinated Universal Time (UTC) in whole hours (UTC−12:00 to UTC+14:00).
- The second format is UTC offset. The UTC offset specifies the time value you must add to the UTC time to get a local time value. It has syntax like [+|-][hh]mm. This is negative if the local time zone is on the west of the Prime Meridian and positive if it is on the east. The hour(hh) must be between -12 and 14, and the minute(mm) between 0 and 59. For example, if you want to set the timezone to New Zealand (Chatham Islands) which is in UTC+12:45, you should set the parameter <timezone> to 1245. Please refer to UTC offset wiki for more information.
[<SNTP server1>]: the first SNTP server.
[<SNTP server2>]: the second SNTP server.
[<SNTP server3>]: the third SNTP server.

Note¶

If the three SNTP servers are not configured, one of the following default servers will be used: “cn.ntp.org.cn”, “ntp.sjtu.edu.cn”, and “us.pool.ntp.org”.
For the query command, <timezone> parameter in the response may be different from the <timezone> parameter in set command. Because the <timezone> parameter supports the second UTC offset format, for example, set AT+CIPSNTPCFG=1,015, for query command, ESP-AT ignores the leading zero of the <timezone> parameter, and the valid value is 15. It does not belong to the first format, so it is parsed according to the second UTC offset format, that is, UTC+00:15, that is, timezone is 0 in the response.

Example¶

// Enable SNTP server, set timezone to China (UTC+08:00)
AT+CIPSNTPCFG=1,8,"cn.ntp.org.cn","ntp.sjtu.edu.cn"
or
AT+CIPSNTPCFG=1,800,"cn.ntp.org.cn","ntp.sjtu.edu.cn"

// Enable SNTP server, set timezone to New York of the United States (UTC−05:00)
AT+CIPSNTPCFG=1,-5,"0.pool.ntp.org","time.google.com"
or
AT+CIPSNTPCFG=1,-500,"0.pool.ntp.org","time.google.com"

// Enable SNTP server, set timezone to New Zealand (Chatham Islands, UTC+12:45)
AT+CIPSNTPCFG=1,1245,"0.pool.ntp.org","time.google.com"

AT+CIPSNTPTIME: Query the SNTP Time¶

Query Command¶

Command:

AT+CIPSNTPTIME?

Response:

+CIPSNTPTIME:<asctime style time>
OK

Note¶

The asctime style time is defined at asctime man page.

Example¶

AT+CIPSNTPCFG=1,8,"cn.ntp.org.cn","ntp.sjtu.edu.cn"

OK

AT+CIPSNTPTIME?
+CIPSNTPTIME:Mon Dec 12 02:33:32 2016
OK

AT+CIUPDATE: Upgrade Firmware Through Wi-Fi¶

ESP-AT upgrades firmware at runtime by downloading the new firmware from a specific server through Wi-Fi and then flash it into some partitions.

Query Command¶

Function:

Query ESP device upgrade status.

Command:

AT+CIUPDATE?

Response:

+CIPUPDATE:<state>
OK

Execute Command¶

Function:

Upgrade OTA the latest version of firmware via TCP/SSL from the server.

Command:

AT+CIUPDATE

Response:

+CIPUPDATE:<state>
OK

or

ERROR

Set Command¶

Function:

Upgrade the specified version of firmware from the server.

Command:

AT+CIUPDATE=<ota mode>[,<version>][,<firmware name>][,<nonblocking>]

Response:

+CIPUPDATE:<state>
OK

or

ERROR

Parameters¶

<ota mode>:
- 0: OTA via HTTP.
- 1: OTA via HTTPS. If it does not work, please check whether ./build.py menuconfig > Component config > AT > OTA based upon ssl is enabled. For more information, please refer to Build Your Own ESP-AT Project.
<version>: AT version, such as, v1.2.0.0, v1.1.3.0, v1.1.2.0.
<firmware name>: firmware to upgrade, such as, ota, mqtt_ca, client_ca or other custom partition in at_customize.csv.
<nonblocking>:
- 0: OTA by blocking mode (In this mode, user can not send AT command until OTA completes successfully or fails.)
- 1: OTA by non-blocking mode (Users need to manually restart after upgrade done (+CIPUPDATE:4).)
<state>:
- 0: Idle.
- 1: Server found.
- 2: Connected to the server.
- 3: Got the upgrade version.
- 4: Upgrade done.
- -1: Upgrade failed.

Notes¶

The speed of the upgrade depends on the network status.
If the upgrade fails due to unfavorable network conditions, AT will return ERROR. Please wait for some time before retrying.
If you use Espressif’s AT BIN, AT+CIUPDATE will download a new AT BIN from the Espressif Cloud.
If you use a user-compiled AT BIN, you need to implement your own AT+CIUPDATE FOTA function. ESP-AT project provides an example of FOTA.
After you upgrade the AT firmware, you are suggested to call the command AT+RESTORE to restore the factory default settings.
Upgraded to an older version is not recommended.

Example¶

AT+CIUPDATE
AT+CIUPDATE=1
AT+CIUPDATE=1,"v1.2.0.0"
AT+CIUPDATE=1,"v2.2.0.0","mqtt_ca"
AT+CIUPDATE=1,"V2.2.0.0","ota",1
AT+CIUPDATE=1,,,1
AT+CIUPDATE=1,,"ota",1
AT+CIUPDATE=1,"V2.2.0.0",,1

AT+CIPDINFO: Set “+IPD” Message Mode¶

Set Command¶

Command:

AT+CIPDINFO=<mode>

Response:

OK

Parameters¶

<mode>:
- 0: does not show the remote host and port in “+IPD” and “+CIPRECVDATA” messages.
- 1: show the remote host and port in “+IPD” and “+CIPRECVDATA” messages.

Example¶

AT+CIPDINFO=1

AT+CIPSSLCCONF: Query/Set SSL Clients¶

Query Command¶

Function:

Query the configuration of each connection where the ESP device runs as an SSL client.

Command:

AT+CIPSSLCCONF?

Response:

+CIPSSLCCONF:<link ID>,<auth_mode>,<pki_number>,<ca_number>
OK

Set Command¶

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSSLCCONF=<auth_mode>[,<pki_number>][,<ca_number>]

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSSLCCONF=<link ID>,<auth_mode>[,<pki_number>][,<ca_number>]

Response:

OK

Parameters¶

<link ID>: ID of the connection (0 ~ max). For multiple connections, if the value is max, it means all connections. By default, max is 5.
<auth_mode>:
- 0: no authentication. In this case <pki_number> and <ca_number> are not required.
- 1: the client provides the client certificate for the server to verify.
- 2: the client loads CA certificate to verify the server’s certificate.
- 3: mutual authentication.
<pki_number>: the index of certificate and private key. If there is only one certificate and private key, the value should be 0.
<ca_number>: the index of CA. If there is only one CA, the value should be 0.

Notes¶

If you want this configuration to take effect immediately, run this command before establishing an SSL connection.
The configuration changes will be saved in the NVS area. If you set the command AT+SAVETRANSLINK to enter SSL Wi-Fi Passthrough Mode on power-up, the ESP device will establish an SSL connection based on this configuration when powered up next time.

AT+CIPSSLCCN: Query/Set the Common Name of the SSL Client¶

Query Command¶

Function:

Query the common name of the SSL client of each connection.

Command:

AT+CIPSSLCCN?

Response:

+CIPSSLCCN:<link ID>,<"common name">
OK

Set Command¶

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSSLCCN=<"common name">

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSSLCCN=<link ID>,<"common name">

Response:

OK

Parameters¶

<link ID>: ID of the connection (0 ~ max). For the single connection, the link ID is 0. For multiple connections, if the value is max, it means all connections. Max is 5 by default.
<”common name”>: this parameter is used to verify the Common Name in the certificate sent by the server. The maximum length of common name is 64 bytes.

Note¶

If you want this configuration to take effect immediately, run this command before establishing the SSL connection.

AT+CIPSSLCSNI: Query/Set SSL Client Server Name Indication (SNI)¶

Query Command¶

Function:

Query the SNI configuration of each connection.

Command:

AT+CIPSSLCSNI?

Response:

+CIPSSLCSNI:<link ID>,<"sni">
OK

Set Command¶

Command:

Single connection: (AT+CIPMUX=0)
AT+CIPSSLCSNI=<"sni">

Multiple connections: (AT+CIPMUX=1)
AT+CIPSSLCSNI=<link ID>,<"sni">

Response:

OK

Parameters¶

<link ID>: ID of the connection (0 ~ max). For the single connection, the link ID is 0. For multiple connections, if the value is max, it means all connections. Max is 5 by default.
<”sni”>: the Server Name Indication in ClientHello. The maximum length of sni is 64 bytes.

Notes¶

If you want this configuration to take effect immediately, run this command before establishing the SSL connection.

AT+CIPSSLCALPN: Query/Set SSL Client Application Layer Protocol Negotiation (ALPN)¶

Query Command¶

Function:

Query the ALPN configuration of each connection where the ESP device runs as an SSL client.

Command:

AT+CIPSSLCALPN?

Response:

+CIPSSLCALPN:<link ID>[,<"alpn">][,<"alpn">][,<"alpn">]

OK

Set Command¶

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSSLCALPN=<counts>[,<"alpn">][,<"alpn">][,<"alpn">]

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSSLCALPN=<link ID>,<counts>[,<"alpn">][,<"alpn">][,<"alpn">]

Response:

OK

Parameters¶

<link ID>: ID of the connection (0 ~ max). For the single connection, the link ID is 0. For multiple connections, if the value is max, it means all connections. Max is 5 by default.
<counts>: the number of ALPNs. Range: [0,5].

0: clean the ALPN configuration.

[1,5]: set the ALPN configuration.

<”alpn”>: a string paramemter showing the ALPN in ClientHello. The maximum length of alpn is limited by the command length.

Note¶

If you want this configuration to take effect immediately, run this command before establishing the SSL connection.

AT+CIPSSLCPSK: Query/Set SSL Client Pre-shared Key (PSK)¶

Query Command¶

Function:

Query the PSK configuration of each connection where the ESP device runs as an SSL client.

Command:

AT+CIPSSLCPSK?

Response:

+CIPSSLCPSK:<link ID>,<"psk">,<"hint">
OK

Set Command¶

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSSLCPSK=<"psk">,<"hint">

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSSLCPSK=<link ID>,<"psk">,<"hint">

Response:

OK

Parameters¶

<link ID>: ID of the connection (0 ~ max). For single connection, <link ID> is 0. For multiple connections, if the value is max, it means all connections, max is 5 by default.
<”psk”>: PSK identity. Maximum length: 32.
<”hint”>: PSK hint. Maximum length: 32.

Notes¶

If you want this configuration to take effect immediately, run this command before establishing the SSL connection.

AT+CIPRECONNINTV: Query/Set the TCP/UDP/SSL reconnection Interval for the Wi-Fi Passthrough Mode ¶

Query Command¶

Function:

Query the automatic connect interval for the Wi-Fi Passthrough Mode.

Command:

AT+CIPRECONNINTV?

Response:

+CIPRECONNINTV:<interval>
OK

Set Command¶

Function:

Set the automatic reconnecting interval when TCP/UDP/SSL transmission breaks in the Wi-Fi Passthrough Mode.

Command:

AT+CIPRECONNINTV=<interval>

Response:

OK

Parameter¶

<interval>: the duration between automatic reconnections. Unit: 100 milliseconds. Default: 1. Range: [1,36000].

Note¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.

Example¶

AT+CIPRECONNINTV=10

AT+CIPRECVMODE: Query/Set Socket Receiving Mode¶

Query Command¶

Function:

Query the socket receiving mode.

Command:

AT+CIPRECVMODE?

Response:

+CIPRECVMODE:<mode>
OK

Set Command¶

Command:

AT+CIPRECVMODE=<mode>

Response:

OK

Parameter¶

<mode>: the receive mode of socket data. Default: 0.
- 0: active mode. ESP-AT will send all the received socket data instantly to the host MCU with header “+IPD”.
- 1: passive mode. ESP-AT will keep the received socket data in an internal buffer (socket receive window, 5760 bytes by default for ESP8266 devices, 5744 bytes by default for non ESP8266 devices), and wait for the host MCU to read. If the buffer is full, the socket transmission will be blocked for TCP/SSL connections, or data will be lost for UDP connections.

Notes¶

The configuration can not be used in the Wi-Fi Passthrough Mode. If it is a UDP transmission in passive mode, data will be lost when the buffer is full.
When ESP-AT receives socket data in passive mode, it will prompt the following messages in different scenarios:
- For multiple connections mode (AT+CIPMUX=1), the message is +IPD,<link ID>,<len>.
- For single connection mode (AT+CIPMUX=0), the message is +IPD,<len>.
<len> is the total length of socket data in the buffer.
You should read data by running AT+CIPRECVDATA once there is a +IPD reported. Otherwise, the next +IPD will not be reported to the host MCU until the previous +IPD has been read.
In case of disconnection, the buffered socket data will still be there and can be read by the MCU until you send AT+CIPCLOSE. In other words, if +IPD has been reported, the message CLOSED of this connection will never come until you send AT+CIPCLOSE or read all data by command AT+CIPRECVDATA.

Example¶

AT+CIPRECVMODE=1

AT+CIPRECVDATA: Obtain Socket Data in Passive Receiving Mode¶

Set Command¶

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPRECVDATA=<len>

// Multiple connections: (AT+CIPMUX=1)
AT+CIPRECVDATA=<link_id>,<len>

Response:

+CIPRECVDATA:<actual_len>,<data>
OK

or

+CIPRECVDATA:<actual_len>,<"remote IP">,<remote port>,<data>
OK

Parameters¶

<link_id>: connection ID in multiple connections mode.
<len>: the max value is 0x7fffffff. If the actual length of the received data is less than len, the actual length will be returned.
<actual_len>: length of the data you actually obtain.
<data>: the data you want to obtain.
<”remote IP”>: string parameter showing the remote IPv4 address or IPv6 address, enabled by the command AT+CIPDINFO=1.
<remote port>: the remote port number, enabled by the command AT+CIPDINFO=1.

Example¶

AT+CIPRECVMODE=1

// For example, if host MCU gets a message of receiving 100-byte data in connection with No.0,
// the message will be "+IPD,0,100".
// Then you can read those 100-byte data by using the command below.
AT+CIPRECVDATA=0,100

AT+CIPRECVLEN: Obtain Socket Data Length in Passive Receiving Mode¶

Query Command¶

Function:

Query the length of the entire data buffered for the connection.

Command:

AT+CIPRECVLEN?

Response:

+CIPRECVLEN:<data length of link0>,<data length of link1>,<data length of link2>,<data length of link3>,<data length of link4>
OK

Parameters¶

<data length of link>: length of the entire data buffered for the connection.

Note¶

For SSL connections, ESP-AT will return the length of the encrypted data, so the returned length will be larger than the real data length.

Example¶

AT+CIPRECVLEN?
+CIPRECVLEN:100,,,,,
OK

AT+PING: Ping the Remote Host¶

Set Command¶

Function:

Ping the remote host.

Command:

AT+PING=<"host">

Response:

+PING:<time>

OK

or

+PING:TIMEOUT   // esp-at returns this response only when the domain name resolution failure or ping timeout

ERROR

Parameters¶

<”host”>: string parameter showing the host IPv4 address or IPv6 address or domain name.
<time>: the response time of ping. Unit: millisecond.

Notes¶

If you want to ping a remote host based on IPv6 network, set AT+CIPV6=1 first, and ensure the connected AP by AT+CWJAP supports IPv6 and esp-at got the IPv6 address which you can check it by AT+CIPSTA.
If the remote host is a domain name string, ping will first resolve the domain name (IPv4 address preferred) from DNS (domain name server), and then ping the remote IP address.

Example¶

AT+PING="192.168.1.1"
AT+PING="www.baidu.com"

// China Future Internet Engineering Center
AT+PING="240c::6666"

AT+CIPDNS: Query/Set DNS Server Information¶

Query Command¶

Function:

Query the current DNS server information.

Command:

AT+CIPDNS?

Response:

+CIPDNS:<enable>[,<"DNS IP1">,<"DNS IP2">,<"DNS IP3">]
OK

Set Command¶

Function:

Set DNS server information.

Command:

AT+CIPDNS=<enable>[,<"DNS IP1">,<"DNS IP2">,<"DNS IP3">]

Response:

OK

or

ERROR

Parameters¶

<enable>: configure DNS settings
- 0: Enable automatic DNS settings from DHCP. The DNS will be restored to 208.67.222.222. Only when DHCP is updated will it take effect.
- 1: Enable manual DNS settings. If you do not set a value for <DNS IPx>, it will use 208.67.222.222 by default.
<”DNS IP1”>: the first DNS IP. For the set command, this parameter only works when you set <enable> to 1, i.e. enable manual DNS settings. If you set <enable> to 1 and a value for this parameter, the ESP-AT will return this parameter as the current DNS setting when you run the query command.
<”DNS IP2”>: the second DNS IP. For the set command, this parameter only works when you set <enable> to 1, i.e. enable manual DNS settings. If you set <enable> to 1 and a value for this parameter, the ESP-AT will return this parameter as the current DNS setting when you run the query command.
<”DNS IP3”>: the third DNS IP. For the set command, this parameter only works when you set <enable> to 1, i.e. enable manual DNS settings. If you set <enable> to 1 and a value for this parameter, the ESP-AT will return this parameter as the current DNS setting when you run the query command.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The three parameters cannot be set to the same server.
When <enable> is set to 1, the DNS server may change according to the configuration of the router which the ESP device is connected to.

Example¶

AT+CIPDNS=0
AT+CIPDNS=1,"208.67.222.222","114.114.114.114","8.8.8.8"

// first DNS Server based on IPv6: China Future Internet Engineering Center
// second DNS Server based on IPv6: google-public-dns-a.google.com
// third DNS Server based on IPv6: main DNS Server based on IPv6 in JiangSu Province, China
AT+CIPDNS=1,"240c::6666","2001:4860:4860::8888","240e:5a::6666"

AT+CIPTCPOPT: Query/Set the Socket Options¶

Query Command¶

Function:

Query current socket options.

Command:

AT+CIPTCPOPT?

Response:

+CIPTCPOPT:<link_id>,<so_linger>,<tcp_nodelay>,<so_sndtimeo>
OK

Set Command¶

Command:

// Single TCP connection (AT+CIPMUX=0):
AT+CIPTCPOPT=[<so_linger>],[<tcp_nodelay>],[<so_sndtimeo>]

// Multiple TCP Connections (AT+CIPMUX=1):
AT+CIPTCPOPT=<link ID>,[<so_linger>],[<tcp_nodelay>],[<so_sndtimeo>]

Response:

OK

or

ERROR

Parameters¶

<link_id>: ID of the connection (0 ~ max). For multiple connections, if the value is max, it means all connections. By default, max is 5.
<so_linger>: configure the SO_LINGER options for the socket. Unit: second. Default: -1.
- = -1: off
- = 0: on, linger time = 0
- > 0: on, linger time = <so_linger>
<tcp_nodelay>: configure the TCP_NODELAY option for the socket. Default: 0.
- 0: disable TCP_NODELAY
- 1: enable TCP_NODELAY
<so_sndtimeo>: configure the SO_SNDTIMEO option for socket. Unit: millisecond. Default: 0.

[ESP32 Only] Bluetooth® Low Energy AT Commands¶

[中文]

ESP32 AT firmware supports Bluetooth® Core Specification Version 5.0.

[ESP32 Only] AT+BLEINIT: Bluetooth LE initialization.
[ESP32 Only] AT+BLEADDR: Query/Set Bluetooth LE device address.
[ESP32 Only] AT+BLENAME: Query/Set Bluetooth LE device name.
[ESP32 Only] AT+BLESCANPARAM: Query/Set parameters of Bluetooth LE scanning.
[ESP32 Only] AT+BLESCAN: Enable Bluetooth LE scanning.
[ESP32 Only] AT+BLESCANRSPDATA: Set Bluetooth LE scan response.
[ESP32 Only] AT+BLEADVPARAM: Query/Set parameters of Bluetooth LE advertising.
[ESP32 Only] AT+BLEADVDATA: Set Bluetooth LE advertising data.
[ESP32 Only] AT+BLEADVDATAEX: Automatically set Bluetooth LE advertising data.
[ESP32 Only] AT+BLEADVSTART: Start Bluetooth LE advertising.
[ESP32 Only] AT+BLEADVSTOP: Stop Bluetooth LE advertising.
[ESP32 Only] AT+BLECONN: Establish Bluetooth LE connection.
[ESP32 Only] AT+BLECONNPARAM: Query/Update parameters of Bluetooth LE connection.
[ESP32 Only] AT+BLEDISCONN: End Bluetooth LE connection.
[ESP32 Only] AT+BLEDATALEN: Set Bluetooth LE data packet length.
[ESP32 Only] AT+BLECFGMTU: Set Bluetooth LE MTU length.
[ESP32 Only] AT+BLEGATTSSRVCRE: Generic Attributes Server (GATTS) creates services.
[ESP32 Only] AT+BLEGATTSSRVSTART: GATTS starts services.
[ESP32 Only] AT+BLEGATTSSRVSTOP: GATTS Stops Services.
[ESP32 Only] AT+BLEGATTSSRV: GATTS discovers services.
[ESP32 Only] AT+BLEGATTSCHAR: GATTS discovers characteristics.
[ESP32 Only] AT+BLEGATTSNTFY: Notify a client of the value of a characteristic value from the server.
[ESP32 Only] AT+BLEGATTSIND: Indicate the characteristic value from the server to a client.
[ESP32 Only] AT+BLEGATTSSETATTR: GATTS sets characteristics.
[ESP32 Only] AT+BLEGATTCPRIMSRV: Generic Attributes Client (GATTC) discovers primary services.
[ESP32 Only] AT+BLEGATTCINCLSRV: GATTC discovers included services.
[ESP32 Only] AT+BLEGATTCCHAR: GATTC discovers characteristics.
[ESP32 Only] AT+BLEGATTCRD: GATTC reads characteristics.
[ESP32 Only] AT+BLEGATTCWR: GATTC writes characteristics.
[ESP32 Only] AT+BLESPPCFG: Query/Set Bluetooth LE SPP parameters.
[ESP32 Only] AT+BLESPP: Enter Bluetooth LE SPP mode.
[ESP32 Only] AT+BLESECPARAM: Query/Set Bluetooth LE encryption parameters.
[ESP32 Only] AT+BLEENC: Initiate Bluetooth LE encryption request.
[ESP32 Only] AT+BLEENCRSP: Respond to the pairing request from the peer device.
[ESP32 Only] AT+BLEKEYREPLY: Reply the key value to the peer device in the legacy connection stage.
[ESP32 Only] AT+BLECONFREPLY: Reply the confirm value to the peer device in the legacy connection stage.
[ESP32 Only] AT+BLEENCDEV: Query bonded Bluetooth LE encryption device list.
[ESP32 Only] AT+BLEENCCLEAR: Clear Bluetooth LE encryption device list.
[ESP32 Only] AT+BLESETKEY: Set Bluetooth LE static pair key.
[ESP32 Only] AT+BLEHIDINIT: Bluetooth LE Human Interface Device (HID) profile initialization.
[ESP32 Only] AT+BLEHIDKB: Send Bluetooth LE HID keyboard information.
[ESP32 Only] AT+BLEHIDMUS: Send Bluetooth LE HID mouse information.
[ESP32 Only] AT+BLEHIDCONSUMER: Send Bluetooth LE HID consumer information.
[ESP32 Only] AT+BLUFI: Start or Stop BluFi.
[ESP32 Only] AT+BLUFINAME: Query/Set BluFi device name.

[ESP32 Only] AT+BLEINIT: Bluetooth LE Initialization¶

Query Command¶

Function:

Check the initialization status of Bluetooth LE.

Command:

AT+BLEINIT?

Response:

If Bluetooth LE is initialized, AT will return:

+BLEINIT:<role>
OK

If Bluetooth LE is not initialized, AT will return:

+BLEINIT:0
OK

Set Command¶

Function:

Initialize the role of Bluetooth LE.

Command:

AT+BLEINIT=<init>

Response:

OK

Parameter¶

<init>:
- 0: deinit Bluetooth LE
- 1: client role
- 2: server role

Notes¶

The file “at_customize.bin” has to be downloaded, so that the relevant commands can be used. Please refer to How To Customize ble services for more details.
Before using other Bluetooth LE AT commands, you should run this command first to trigger the initialization process.
After the initialization, the Bluetooth LE role cannot be changed unless you run AT+RST to restart the system first and then re-initialize the Bluetooth LE role.
If you use an ESP device as a Bluetooth LE server, a service bin should be downloaded into flash.
- To learn how to generate a service bin, please refer to esp-at/tools/readme.md.
- The download address of the service bin is the “ble_data” address in esp-at/module_config/module_${platform}_default/at_customize.csv.

Example¶

AT+BLEINIT=1

[ESP32 Only] AT+BLEADDR: Query/Set Bluetooth LE Device Address¶

Query Command¶

Function:

Query the Bluetooth LE Public Address.

Command:

AT+BLEADDR?

Response:

+BLEADDR:<BLE_public_addr>
OK

Set Command¶

Function:

Set the Bluetooth LE address type.

Command:

AT+BLEADDR=<addr_type>[,<random_addr>]

Response:

OK

Parameter¶

<addr_type>:
- 0: Public Address
- 1: Random Address

Note¶

A Static Address should meet the following requirements:
- The two most significant bits of the address should be equal to 1.
- At least one bit of the random part of the address should be 0.
- At least one bit of the random part of the address should be 1.

Example¶

AT+BLEADDR=1,"f8:7f:24:87:1c:7b"    // Set Random Device Address, Static Address
AT+BLEADDR=1                        // Set Random Device Address, Private Address
AT+BLEADDR=0                        // Set Public Device Address

[ESP32 Only] AT+BLENAME: Query/Set Bluetooth LE Device Name¶

Query Command¶

Function:

Query the Bluetooth LE device name.

Command:

AT+BLENAME?

Response:

+BLENAME:<device_name>
OK

Set Command¶

Function:

Set the Bluetooth LE device name.

Command:

AT+BLENAME=<device_name>

Response:

OK

Parameter¶

<device_name>: the Bluetooth LE device name. The maximum length is 32. Default: “BLE_AT”.

Note¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.

Example¶

AT+BLENAME="esp_demo"

[ESP32 Only] AT+BLESCANPARAM: Query/Set Parameters of Bluetooth LE Scanning¶

Query Command¶

Function:

Query the parameters of Bluetooth LE scanning.

Command:

AT+BLESCANPARAM?

Response:

+BLESCANPARAM:<scan_type>,<own_addr_type>,<filter_policy>,<scan_interval>,<scan_window>
OK

Set Command¶

Function:

Set the parameters of Bluetooth LE scanning.

Command:

AT+BLESCANPARAM=<scan_type>,<own_addr_type>,<filter_policy>,<scan_interval>,<scan_window>

Response:

OK

Parameters¶

<scan_type>:
- 0: passive scan
- 1: active scan
<own_addr_type>:
- 0: Public Address
- 1: Random Address
- 2: RPA Public Address
- 3: RPA Random Address
<filter_policy>:
- 0: BLE_SCAN_FILTER_ALLOW_ALL
- 1: BLE_SCAN_FILTER_ALLOW_ONLY_WLST
- 2: BLE_SCAN_FILTER_ALLOW_UND_RPA_DIR
- 3: BLE_SCAN_FILTER_ALLOW_WLIST_PRA_DIR
<scan_interval>: scan interval
<scan_window>: scan window

Note¶

The parameter <scan_window> CANNOT be larger than <scan_interval>.

Example¶

AT+BLEINIT=1   // role: client
AT+BLESCANPARAM=0,0,0,100,50

[ESP32 Only] AT+BLESCAN: Enable Bluetooth LE Scanning¶

Set Command¶

Function:

Enable/disable scanning.

Command:

AT+BLESCAN=<enable>[,<interval>][,<filter_type>,<filter_param>]

Response:

+BLESCAN:<addr>,<rssi>,<adv_data>,<scan_rsp_data>,<addr_type>
OK

Parameters¶

<enable>:
- 1: enable continuous scanning.
- 0: disable continuous scanning.
[<interval>]: optional parameter. Unit: second.
- If you want to disable the scanning, this parameter should be omitted.
- If you want to enable the scanning, set a value for this parameter:
- When you set it to 0, it means that scanning is continuous.
- When set it to a value other than 0, for example, AT+BLESCAN=1,3, it means that scanning will last for 3 seconds and then stop automatically. The scanning results will be returned.
[<filter_type>]: filtering option.
- 1: “MAC”.
- 2: “NAME”.
<filter_param>: filtering parameter showing the remote device MAC address or remote device name.
<addr>: Bluetooth LE address.
<rssi>: signal strength.
<adv_data>: advertising data.
<scan_rsp_data>: scan response data.
<addr_type>: the address type of broadcasters.

Notes¶

The response OK does not necessarily come before the response +BLESCAN:<addr>,<rssi>,<adv_data>,<scan_rsp_data>,<addr_type>. It may be output before +BLESCAN:<addr>,<rssi>,<adv_data>,<scan_rsp_data>,<addr_type> or after it.

Example¶

AT+BLEINIT=1    // role: client
AT+BLESCAN=1    // start scanning
AT+BLESCAN=0    // stop scanning
AT+BLESCAN=1,3,1,"24:0A:C4:96:E6:88"  // start scanning, filter type is MAC address
AT+BLESCAN=1,3,2,"ESP-AT"  // start scanning, filter type is device name

[ESP32 Only] AT+BLESCANRSPDATA: Set Bluetooth LE Scan Response¶

Set Command¶

Function:

Set scan response.

Command:

AT+BLESCANRSPDATA=<scan_rsp_data>

Response:

OK

Parameter¶

<scan_rsp_data>: scan response data is a HEX string. For example, if you want to set the response data to “0x11 0x22 0x33 0x44 0x55”, the command should be AT+BLESCANRSPDATA="1122334455".

Example¶

AT+BLEINIT=2   // role: server
AT+BLESCANRSPDATA="1122334455"

[ESP32 Only] AT+BLEADVPARAM: Query/Set Parameters of Bluetooth LE Advertising¶

Query Command¶

Function:

Query the parameters of advertising.

Command:

AT+BLEADVPARAM?

Response:

+BLEADVPARAM:<adv_int_min>,<adv_int_max>,<adv_type>,<own_addr_type>,<channel_map>,<adv_filter_policy>,<peer_addr_type>,<peer_addr>
OK

Set Command¶

Function:

Set the parameters of advertising.

Command:

AT+BLEADVPARAM=<adv_int_min>,<adv_int_max>, <adv_type>,<own_addr_type>,<channel_map>[,<adv_filter_policy>][,<peer_addr_type>] [,<peer_addr>]

Response:

OK

Parameters¶

<adv_int_min>: minimum advertising interval. It should be less than the value of <adv_int_max>. Range: 0x0020 ~ 0x4000.
<adv_int_max>: maximum advertising interval. It should be more than the value of <adv_int_min>. Range: 0x0020 ~ 0x4000.
<adv_type>:
- 0: ADV_TYPE_IND
- 2: ADV_TYPE_SCAN_IND
- 3: ADV_TYPE_NONCONN_IND
<own_addr_type>: own Bluetooth LE address type.
- 0: BLE_ADDR_TYPE_PUBLIC
- 1: BLE_ADDR_TYPE_RANDOM
<channel_map>: channel of advertising.
- 1: ADV_CHNL_37
- 2: ADV_CHNL_38
- 4: ADV_CHNL_39
- 7: ADV_CHNL_ALL
[<adv_filter_policy>]: filter policy of advertising.
- 0: ADV_FILTER_ALLOW_SCAN_ANY_CON_ANY
- 1: ADV_FILTER_ALLOW_SCAN_WLST_CON_ANY
- 2: ADV_FILTER_ALLOW_SCAN_ANY_CON_WLST
- 3: ADV_FILTER_ALLOW_SCAN_WLST_CON_WLST
[<peer_addr_type>]: remote Bluetooth LE address type.
- 0: PUBLIC
- 1: RANDOM
[<peer_addr>]: remote Bluetooth LE address.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEADVPARAM=50,50,0,0,4,0,0,"12:34:45:78:66:88"

[ESP32 Only] AT+BLEADVDATA: Set Bluetooth LE Advertising Data¶

Set Command¶

Function:

Set advertising data.

Command:

AT+BLEADVDATA=<adv_data>

Response:

OK

Parameter¶

<adv_data>: advertising data in HEX string. For example, to set the advertising data to “0x11 0x22 0x33 0x44 0x55”, the command should be AT+BLEADVDATA="1122334455".

Note¶

If advertising data is preset by command AT+BLEADVDATAEX=<dev_name>,<uuid>,<manufacturer_data>,<include_power>, it will be overwritten by this command.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEADVDATA="1122334455"

[ESP32 Only] AT+BLEADVDATAEX: Automatically Set Bluetooth LE Advertising Data¶

Query Command¶

Function:

Query the parameters of advertising data.

Command:

AT+BLEADVDATAEX?

Response:

+BLEADVDATAEX:<dev_name>,<uuid>,<manufacturer_data>,<include_power>

OK

Set Command¶

Function:

Set the advertising data and start advertising.

Command:

AT+BLEADVDATAEX=<dev_name>,<uuid>,<manufacturer_data>,<include_power>

Response:

OK

Parameters¶

<dev_name>: string parameter showing a device name. For example, if you want to set the device name to “just-test”, the command should be AT+BLEADVSTARTEX="just-test",<uuid>,<manufacturer_data>,<include_power>.
<uuid>: string parameter. For example, if you want to set the UUID to “0xA002”, the command should be AT+BLEADVSTARTEX=<dev_name>,"A002",<manufacturer_data>,<include_power>.
<manufacturer_data>: manufacturer data in HEX string. For example, if you set the manufacturer data to “0x11 0x22 0x33 0x44 0x55”, the command should be AT+BLEADVSTARTEX=<dev_name>,<uuid>,"1122334455",<include_power>.
<include_power>: If you need to include the TX power in the advertising data, you should set the parameter to 1. Otherwise, set it to 0.

Note¶

If advertising data is preset by command AT+BLEADVDATA=<adv_data>, it will be overwritten by this command.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEADVDATAEX="ESP-AT","A002","0102030405",1

[ESP32 Only] AT+BLEADVSTART: Start Bluetooth LE Advertising¶

Execute Command¶

Function:

Start advertising.

Command:

AT+BLEADVSTART

Response:

OK

Notes¶

If advertising parameters are NOT set by command AT+BLEADVPARAM=<adv_parameter>, the default parameters will be used.
If advertising data is NOT set by command AT+BLEADVDATA=<adv_data>, the advertising playload will be empty.
If advertising data is preset by command AT+BLEADVDATA=<adv_data>, it will be overwritten by AT+BLEADVDATAEX=<dev_name>,<uuid>,<manufacturer_data>,<include_power> and vice versa.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEADVSTART

[ESP32 Only] AT+BLEADVSTOP: Stop Bluetooth LE Advertising¶

Execute Command¶

Function:

Stop advertising.

Command:

AT+BLEADVSTOP

Response:

OK

Note¶

After the start of advertising, if the Bluetooth LE connection is established successfully, it will stop advertising automatically. In such a case, this command does NOT need to be called.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEADVSTART
AT+BLEADVSTOP

[ESP32 Only] AT+BLECONN: Establish Bluetooth LE Connection¶

Query Command¶

Function:

Query the Bluetooth LE connection.

Command:

AT+BLECONN?

Response:

+BLECONN:<conn_index>,<remote_address>
OK

If the connection has not been established, there will be no <conn_index> and <remote_address> in the response.

Set Command¶

Function:

Establish the Bluetooth LE connection.

Command:

AT+BLECONN=<conn_index>,<remote_address>[,<addr_type>,<timeout>]

Response:

OK

If the connection is established successfully, it will prompt:

+BLECONN:<conn_index>,<remote_address>

Otherwise, it will prompt:

+BLECONN:<conn_index>,-1

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<remote_address>: remote Bluetooth LE address.
[<addr_type>]: the address type of broadcasters.
[<timeout>]: the timeout for the connection command. Unit: second. Range: [3,30].

Notes¶

It is recommended to scan devices by running AT+BLESCAN before initiating a new connection to ensure that the target device is in the broadcast state.
The maximum timeout for connection is 30 seconds.
If the Bluetooth LE server is initialized and the connection is established successfully, you can use this command to discover the services in the peer device (GATTC). The following GATTC commands can also be used:

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:0a:c4:09:34:23",0,10

[ESP32 Only] AT+BLECONNPARAM: Query/Update Parameters of Bluetooth LE Connection¶

Query Command¶

Function:

Query the parameters of Bluetooth LE connection.

Command:

AT+BLECONNPARAM?

Response:

+BLECONNPARAM:<conn_index>,<min_interval>,<max_interval>,<cur_interval>,<latency>,<timeout>
OK

Set Command¶

Function:

Update the parameters of Bluetooth LE connection.

Command:

AT+BLECONNPARAM=<conn_index>,<min_interval>,<max_interval>,<latency>,<timeout>

Response:

OK

If the setting fails, it will prompt the message below:

+BLECONNPARAM: <conn_index>,-1

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<min_interval>: minimum connecting interval. Range: 0x0006 ~ 0x0C80.
<max_interval>: maximum connecting interval. Range: 0x0006 ~ 0x0C80.
<cur_interval>: current connecting interval.
<latency>: latency. Range: 0x0000 ~ 0x01F3.
<timeout>: timeout. Range: 0x000A ~ 0x0C80.

Note¶

This command only supports the client role when updating its connection parameters. Of course, the connection has to be established first.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:0a:c4:09:34:23"
AT+BLECONNPARAM=0,12,14,1,500

[ESP32 Only] AT+BLEDISCONN: End Bluetooth LE Connection¶

Execute Command¶

Function:

End the Bluetooth LE connection.

Command:

AT+BLEDISCONN=<conn_index>

Response:

OK  // The AT+BLEDISCONN command is received.
+BLEDISCONN:<conn_index>,<remote_address>  // The command is successful.

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<remote_address>: remote Bluetooth LE address.

Note¶

Only clients can call this command to terminate the connection.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:0a:c4:09:34:23"
AT+BLEDISCONN=0

[ESP32 Only] AT+BLEDATALEN: Set Bluetooth LE Data Packet Length¶

Set Command¶

Function:

Set the length of Bluetooth LE data packet.

Command:

AT+BLEDATALEN=<conn_index>,<pkt_data_len>

Response:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<pkt_data_len>: data packet’s length. Range: 0x001b ~ 0x00fb.

Note¶

The Bluetooth LE connection has to be established first.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:0a:c4:09:34:23"
AT+BLEDATALEN=0,30

[ESP32 Only] AT+BLECFGMTU: Set Bluetooth LE MTU Length¶

Query Command¶

Function:

Query the length of the maximum transmission unit (MTU).

Command:

AT+BLECFGMTU?

Response:

+BLECFGMTU:<conn_index>,<mtu_size>
OK

Set Command¶

Function:

Set the length of the maximum transmission unit (MTU).

Command:

AT+BLECFGMTU=<conn_index>,<mtu_size>

Response:

OK  // The command is received.

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<mtu_size>: MTU length.

Notes¶

Bluetooth LE connection has to be established first.
Only the client can call this command to set the length of MTU.
The actual length of MTU needs to be negotiated. The OK response only indicates an attempt to negotiate the length. The actual length may not be the value you set. Therefore, it is recommended to run command AT+BLECFGMTU? to query the actual length.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:0a:c4:09:34:23"
AT+BLECFGMTU=0,300

[ESP32 Only] AT+BLEGATTSSRVCRE: GATTS Creates Services¶

Execute Command¶

Function:

The Generic Attributes Server (GATTS) creates Bluetooth LE services.

Command:

AT+BLEGATTSSRVCRE

Response:

OK

Notes¶

If you are using an ESP device as a Bluetooth LE server, a service bin should be downloaded into flash in order to provide services.
- To learn how to generate a service bin, please refer to esp-at/tools/readme.md.
- The download address of the service bin is the “ble_data” address in esp-at/module_config/module_${platform}_default/at_customize.csv.
This command should be called immediately to create services, right after the Bluetooth LE server is initialized; If a Bluetooth LE connection is established first, the service creation will fail.
If the Bluetooth LE client is initialized, you can use this command to create local services. Some GATTS commands can also be used, such as those to start and stop services, set attribute values, and send notifications/indications. See the list below for the specific commands.
- AT+BLEGATTSSRVCRE (It is recommended to execute this command before the connection is established)
- AT+BLEGATTSSRVSTART (It is recommended to execute this command before the connection is established)
- AT+BLEGATTSSRV
- AT+BLEGATTSCHAR
- AT+BLEGATTSNTFY
- AT+BLEGATTSIND
- AT+BLEGATTSSETATTR

Example¶

AT+BLEINIT=2   // role: server
AT+BLEGATTSSRVCRE

[ESP32 Only] AT+BLEGATTSSRVSTART: GATTS Starts Services¶

Execute Command¶

Function:

GATTS starts all services.

Command:

AT+BLEGATTSSRVSTART

Set Command¶

Function:

GATTS starts a specific service.

Command:

AT+BLEGATTSSRVSTART=<srv_index>

Response:

OK

Parameter¶

<srv_index>: service’s index starting from 1.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART

[ESP32 Only] AT+BLEGATTSSRVSTOP: GATTS Stops Services¶

Execute Command¶

Function:

GATTS stops all services.

Command:

AT+BLEGATTSSRVSTOP

Set Command¶

Function:

GATTS stops a specific service.

Command:

AT+BLEGATTSSRVSTOP=<srv_index>

Response:

OK

Parameter¶

<srv_index>: service’s index starting from 1.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART
AT+BLEGATTSSRVSTOP

[ESP32 Only] AT+BLEGATTSSRV: GATTS Discovers Services¶

Query Command¶

Function:

GATTS discovers services.

Command:

AT+BLEGATTSSRV?

Response:

+BLEGATTSSRV:<srv_index>,<start>,<srv_uuid>,<srv_type>
OK

Parameters¶

<srv_index>: service’s index starting from 1.
<start>:
- 0: the service has not started.
- 1: the service has already started.
<srv_uuid>: service’s UUID.
<srv_type>: service’s type.
- 0: not primary service.
- 1: primary service.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRV?

[ESP32 Only] AT+BLEGATTSCHAR: GATTS Discovers Characteristics¶

Query Command¶

Function:

GATTS discovers characteristics.

Command:

AT+BLEGATTSCHAR?

Response:

The response for a characteristic:

+BLEGATTSCHAR:"char",<srv_index>,<char_index>,<char_uuid>,<char_prop>

The response for a descriptor:

+BLEGATTSCHAR:"desc",<srv_index>,<char_index>,<desc_index>
OK

Parameters¶

<srv_index>: service’s index starting from 1.
<char_index>: characteristic’s index starting from 1.
<char_uuid>: characteristic’s UUID.
<char_prop>: characteristic’s properties.
<desc_index>: descriptor’s index.
<desc_uuid>: descriptor’s UUID.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART
AT+BLEGATTSCHAR?

[ESP32 Only] AT+BLEGATTSNTFY: Notify a Client of the Value of a Characteristic Value from the Server¶

Set Command¶

Function:

Notify a client of the value of a characteristic value from the server.

Command:

AT+BLEGATTSNTFY=<conn_index>,<srv_index>,<char_index>,<length>

Response:

The symbol > indicates that AT is ready for receiving serial data, and you can enter data now. When the requirement of data length determined by the parameter <length> is met, the notification starts.

If the data transmission is successful, AT returns:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index. It can be fetched with command AT+BLEGATTSCHAR?.
<char_index>: characteristic’s index. It can be fetched with command AT+BLEGATTSCHAR?.
<length>: data length.

Example¶

AT+BLEINIT=2      // Role: server.
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART
AT+BLEADVSTART    // Start advertising. After the client is connected, it must be configured to receive notifications.
AT+BLEGATTSCHAR?  // Query the characteristics which the client will be notified of.
// For example, to notify of 4-byte data using the 6th characteristic in the 3rd service, use the following command:
AT+BLEGATTSNTFY=0,3,6,4
// After the symbol ">" shows, enter the 4-byte data, such as "1234". Then the data will be transmitted automatically.

[ESP32 Only] AT+BLEGATTSIND: Indicate the Characteristic Value from the Server to a Client¶

Set Command¶

Function:

Indicate the characteristic value from the server to a client.

Command:

AT+BLEGATTSIND=<conn_index>,<srv_index>,<char_index>,<length>

Response:

The symbol > indicates that AT is ready for receiving serial data and you can enter data now. When the requirement of data length determined by the parameter <length> is met, the indication starts.

If the data transmission is successful, AT returns:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index. It can be fetched with command AT+BLEGATTSCHAR?.
<char_index>: characteristic’s index; it can be fetched with command AT+BLEGATTSCHAR?.
<length>: data length.

Example¶

AT+BLEINIT=2      // Role: server
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART
AT+BLEADVSTART    // Start advertising. After the client is connected, it must be configured to receive indications.
AT+BLEGATTSCHAR?  // Query the characteristics which the client can receive indications.
// For example, to indicate 4 bytes of data using the 7th characteristic in the 3rd service, use the following command:
AT+BLEGATTSIND=0,3,7,4
// After the symbol ">" shows, input 4 bytes of data, such as "1234". Then the data will be transmitted automatically.

[ESP32 Only] AT+BLEGATTSSETATTR: GATTS Sets Characteristics¶

Set Command¶

Function:

GATTS sets its characteristic (descriptor).

Command:

AT+BLEGATTSSETATTR=<srv_index>,<char_index>,[<desc_index>],<length>

Response:

The symbol > indicates that AT is ready for receiving serial data and you can enter data now. When the requirement of data length determined by the parameter <length> is met, the setting starts.

If the setting is successful, AT returns:

OK

Parameters¶

<srv_index>: service’s index. It can be fetched with command AT+BLEGATTSCHAR?.
<char_index>: characteristic’s index; it can be fetched with command AT+BLEGATTSCHAR?.
[<desc_index>]: descriptor’s index.
- If it is set, this command is used to set the value of the descriptor.
- Otherwise, this command is used to set the value of the characteristic.
<length>: data length.

Note¶

If the value of <length> is larger than the maximum length allowed, the setting will fail. The service table is defined in components/customized_partitions/raw_data/ble_data.

Example¶

AT+BLEINIT=2   // Role: server.
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART
AT+BLEGATTSCHAR?
// For example, to set 1 byte of data of the 1st characteristic in the 1st service, use the following command:
AT+BLEGATTSSETATTR=1,1,,1
// After the symbol ">" shows, input 1 byte of data, such as "8". Then the setting starts.

[ESP32 Only] AT+BLEGATTCPRIMSRV: GATTC Discovers Primary Services¶

Query Command¶

Function:

Generic Attributes Client (GATTC) discovers primary services.

Command:

AT+BLEGATTCPRIMSRV=<conn_index>

Response:

+BLEGATTCPRIMSRV:<conn_index>,<srv_index>,<srv_uuid>,<srv_type>
OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index starting from 1.
<srv_uuid>: service’s UUID.
<srv_type>: service’s type.
- 0: not primary service.
- 1: primary service.

Note¶

The Bluetooth LE connection has to be established first.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:12:5f:9d:91:98"
AT+BLEGATTCPRIMSRV=0

[ESP32 Only] AT+BLEGATTCINCLSRV: GATTC Discovers Included Services¶

Set Command¶

Function:

GATTC discovers included services.

Command:

AT+BLEGATTCINCLSRV=<conn_index>,<srv_index>

Response:

+BLEGATTCINCLSRV:<conn_index>,<srv_index>,<srv_uuid>,<srv_type>,<included_srv_uuid>,<included_srv_type>
OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index. It can be fetched with command AT+BLEGATTCPRIMSRV=<conn_index>.
<srv_uuid>: service’s UUID.
<srv_type>: service’s type.
- 0: not primary service.
- 1: primary service.
<included_srv_uuid>: included service’s UUID.
<included_srv_type>: included service’s type.
- 0: not primary service.
- 1: primary service.

Note¶

The Bluetooth LE connection has to be established first.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:12:5f:9d:91:98"
AT+BLEGATTCPRIMSRV=0
AT+BLEGATTCINCLSRV=0,1  // set a specific index according to the result of the previous command

[ESP32 Only] AT+BLEGATTCCHAR: GATTC Discovers Characteristics¶

Set Command¶

Function:

GATTC discovers characteristics.

Command:

AT+BLEGATTCCHAR=<conn_index>,<srv_index>

Response:

The response for a characteristic:

+BLEGATTCCHAR:"char",<conn_index>,<srv_index>,<char_index>,<char_uuid>,<char_prop>

The response for a descriptor:

+BLEGATTCCHAR:"desc",<conn_index>,<srv_index>,<char_index>,<desc_index>,<desc_uuid>
OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index. It can be fetched with command AT+BLEGATTCPRIMSRV=<conn_index>.
<char_index>: characteristic’s index starting from 1.
<char_uuid>: characteristic’s UUID.
<char_prop>: characteristic’s properties.
<desc_index>: descriptor’s index.
<desc_uuid>: descriptor’s UUID.

Note¶

The Bluetooth LE connection has to be established first.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:12:5f:9d:91:98"
AT+BLEGATTCPRIMSRV=0
AT+BLEGATTCCHAR=0,1 // set a specific index according to the result of the previous command

[ESP32 Only] AT+BLEGATTCRD: GATTC Reads Characteristics¶

Set Command¶

Function:

GATTC reads a characteristic or descriptor.

Command:

AT+BLEGATTCRD=<conn_index>,<srv_index>,<char_index>[,<desc_index>]

Response:

+BLEGATTCRD:<conn_index>,<len>,<value>
OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index. It can be fetched with command AT+BLEGATTCPRIMSRV=<conn_index>.
<char_index>: characteristic’s index; it can be fetched with command AT+BLEGATTCCHAR=<conn_index>,<srv_index>.
[<desc_index>]: descriptor’s index.
- If it is set, the value of the target descriptor will be read.
- if it is not set, the value of the target characteristic will be read.
<len>: data length.
<char_value>: characteristic’s value. HEX string is read by command AT+BLEGATTCRD=<conn_index>,<srv_index>,<char_index>. For example, if the response is +BLEGATTCRD:1,30, it means that the value length is 1, and the content is “0x30”.
[<desc_value>]: descriptor’s value. HEX string is read by command AT+BLEGATTCRD=<conn_index>,<srv_index>,<char_index>,<desc_index>. For example, if the response is +BLEGATTCRD:4,30313233, it means that the value length is 4, and the content is “0x30 0x31 0x32 0x33”.

Notes¶

The Bluetooth LE connection has to be established first.
If the target characteristic cannot be read, it will return “ERROR”.

Example¶

AT+BLEINIT=1   // Role: client.
AT+BLECONN=0,"24:12:5f:9d:91:98"
AT+BLEGATTCPRIMSRV=0
AT+BLEGATTCCHAR=0,3 // Set a specific index according to the result of the previous command.
// For example, to read 1st descriptor of the 2nd characteristic in the 3rd service, use the following command:
AT+BLEGATTCRD=0,3,2,1

[ESP32 Only] AT+BLEGATTCWR: GATTC Writes Characteristics¶

Set Command¶

Function:

GATTC writes characteristics or descriptors.

Command:

AT+BLEGATTCWR=<conn_index>,<srv_index>,<char_index>[,<desc_index>],<length>

Response:

The symbol > indicates that AT is ready for receiving serial data and you can enter data now. When the requirement of data length determined by the parameter <length> is met, the writing starts.

If the setting is successful, AT returns:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index. It can be fetched with command AT+BLEGATTCPRIMSRV=<conn_index>.
<char_index>: characteristic’s index; it can be fetched with command AT+BLEGATTCCHAR=<conn_index>,<srv_index>.
[<desc_index>]: descriptor’s index.
- If it is set, the value of the target descriptor will be written.
- If it is not set, the value of the target characteristic will be written.
<length>: data length.

Notes¶

The Bluetooth LE connection has to be established first.
If the target characteristic cannot be written, it will return “ERROR”.

Example¶

AT+BLEINIT=1   // Role: client.
AT+BLECONN=0,"24:12:5f:9d:91:98"
AT+BLEGATTCPRIMSRV=0
AT+BLEGATTCCHAR=0,3 // Set a specific index according to the result of the previous command.
// For example, to write 6 bytes of data to the 4th characteristic in the 3rd service, use the following command:
AT+BLEGATTCWR=0,3,4,,6
// After the symbol ">" shows, input 6 bytes of data, such as "123456". Then the writing starts.

[ESP32 Only] AT+BLESPPCFG: Query/Set Bluetooth LE SPP Parameters¶

Query Command¶

Function:

Query the parameters of Bluetooth LE Serial Port Profile (SPP).

Command:

AT+BLESPPCFG?

Response:

+BLESPPCFG:<tx_service_index>,<tx_char_index>,<rx_service_index>,<rx_char_index>
OK

Set Command¶

Function:

Set or reset the parameters of Bluetooth LE SPP.

Command:

AT+BLESPPCFG=<cfg_enable>[,<tx_service_index>,<tx_char_index>,<rx_service_index>,<rx_char_index>]

Response:

OK

Parameters¶

<cfg_enable>:
- 0: all the SPP parameters will be reset, and the following four parameters don’t need input.
- 1: you should input the following four parameters.
<tx_service_index>: tx service’s index. It can be fetched with command AT+BLEGATTCPRIMSRV=<conn_index> and AT+BLEGATTSSRV?.
<tx_char_index>: tx characteristic’s index. It can be fetched with command AT+BLEGATTCCHAR=<conn_index>,<srv_index> and AT+BLEGATTSCHAR?.
<rx_service_index>: rx service’s index. It can be fetched with command AT+BLEGATTCPRIMSRV=<conn_index> and AT+BLEGATTSSRV?.
<rx_char_index>: rx characteristic’s index. It can be fetched with command AT+BLEGATTCCHAR=<conn_index>,<srv_index> and AT+BLEGATTSCHAR?.

Notes¶

In Bluetooth LE client, the property of tx characteristic must be write with response or write without response, and the property of rx characteristic must be indicate or notify.
In Bluetooth LE server, the property of tx characteristic must be indicate or notify, and the property of rx characteristic must be write with response or write without response.

Example¶

AT+BLESPPCFG=0          // reset Bluetooth LE SPP parameters
AT+BLESPPCFG=1,3,5,3,7  // set Bluetooth LE SPP parameters
AT+BLESPPCFG?           // query Bluetooth LE SPP parameters

[ESP32 Only] AT+BLESPP: Enter Bluetooth LE SPP Mode¶

Execute Command¶

Function:

Enter Bluetooth LE SPP mode.

Command:

AT+BLESPP

Response:

Notes¶

If the Bluetooth LE SPP parameters are illegal, this command will return ERROR.
During the SPP transmission, AT will not prompt any connection status changes unless bit2 of AT+SYSMSG is 1.

Example¶

AT+BLESPP   // enter Bluetooth LE SPP mode

[ESP32 Only] AT+BLESECPARAM: Query/Set Bluetooth LE Encryption Parameters¶

Query Command¶

Function:

Query the parameters of Bluetooth LE SMP.

Command:

AT+BLESECPARAM?

Response:

+BLESECPARAM:<auth_req>,<iocap>,<key_size>,<init_key>,<rsp_key>,<auth_option>
OK

Set Command¶

Function:

Set the parameters of Bluetooth LE SMP.

Command:

AT+BLESECPARAM=<auth_req>,<iocap>,<key_size>,<init_key>,<rsp_key>[,<auth_option>]

Response:

OK

Parameters¶

<auth_req>: authentication request.
- 0: NO_BOND
- 1: BOND
- 4: MITM
- 8: SC_ONLY
- 9: SC_BOND
- 12: SC_MITM
- 13: SC_MITM_BOND
<iocap>: input and output capability.
- 0: DisplayOnly
- 1: DisplayYesNo
- 2: KeyboardOnly
- 3: NoInputNoOutput
- 4: Keyboard display
<key_size>: key length. Range: 7 ~ 16 bytes.
<init_key>: initial key represented in bit combinations.
<rsp_key>: response key represented in bit combinations.
<auth_option>: authentication option of security.
- 0: Select the security level automatically.
- 1: If it cannot follow the preset security level, the connection will disconnect.

Note¶

The bit pattern for parameters <init_key> and <rsp_key> is:
- Bit0: Used to exchange the encryption key in the init key & response key.
- Bit1: Used to exchange the IRK key in the init key & response key.
- Bit2: Used to exchange the CSRK key in the init key & response key.
- Bit3: Used to exchange the link key (only used in the Bluetooth LE & BR/EDR coexist mode) in the init key & response key.

Example¶

AT+BLESECPARAM=1,4,16,3,3,0

[ESP32 Only] AT+BLEENC: Initiate Bluetooth LE Encryption Request¶

Set Command¶

Function:

Start a pairing request

Command:

AT+BLEENC=<conn_index>,<sec_act>

Response:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<sec_act>:
- 0: SEC_NONE
- 1: SEC_ENCRYPT
- 2: SEC_ENCRYPT_NO_MITM
- 3: SEC_ENCRYPT_MITM

Note¶

Before running this command, please set the security parameters and connection with remote devices.

Example¶

AT+BLESECPARAM=1,4,16,3,3
AT+BLEENC=0,3

[ESP32 Only] AT+BLEENCRSP: Respond to the Pairing Request from the Peer Device¶

Set Command¶

Function:

Respond to the pairing request from the peer device.

Command:

AT+BLEENCRSP=<conn_index>,<accept>

Response:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<accept>:
- 0: reject
- 1: accept

Note¶

After running this command, AT will output the pairing result at the end of the pairing process.

+BLEAUTHCMPL:<conn_index>,<enc_result>

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<enc_result>:
- 0: encryption succeeded
- 1: encryption failed

Example¶

AT+BLEENCRSP=0,1

[ESP32 Only] AT+BLEKEYREPLY: Reply the Key Value to the Peer Device in the Legacy Connection Stage¶

Set Command¶

Function:

Reply a pairing key.

Command:

AT+BLEKEYREPLY=<conn_index>,<key>

Response:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<key>: pairing key.

Example¶

AT+BLEKEYREPLY=0,649784

[ESP32 Only] AT+BLECONFREPLY: Reply the Confirm Value to the Peer Device in the Legacy Connection Stage¶

Set Command¶

Function:

Reply a pairing result.

Command:

AT+BLECONFREPLY=<conn_index>,<confirm>

Response:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<confirm>:
- 0: No
- 1: Yes

Example¶

AT+BLECONFREPLY=0,1

[ESP32 Only] AT+BLEENCDEV: Query Bonded Bluetooth LE Encryption Device List¶

Query Command¶

Function:

Query bonded Bluetooth LE encryption device list.

Command:

AT+BLEENCDEV?

Response:

+BLEENCDEV:<enc_dev_index>,<mac_address>
OK

Parameters¶

<enc_dev_index>: index of the bonded devices.
<mac_address>: MAC address.

Example¶

AT+BLEENCDEV?

[ESP32 Only] AT+BLEENCCLEAR: Clear Bluetooth LE Encryption Device List¶

Set Command¶

Function:

Remove a device from the security database list with a specific index.

Command:

AT+BLEENCCLEAR=<enc_dev_index>

Response:

OK

Execute Command¶

Function:

Remove all devices from the security database.

Command:

AT+BLEENCCLEAR

Response:

OK

Parameter¶

<enc_dev_index>: index of the bonded devices.

Example¶

AT+BLEENCCLEAR

[ESP32 Only] AT+BLESETKEY: Set Bluetooth LE Static Pair Key¶

Query Command¶

Function:

Query the Bluetooth LE static pair key. If it is not set, AT will return -1.

Command:

AT+BLESETKEY?

Response:

+BLESETKEY:<static_key>
OK

Set Command¶

Function:

Set a Bluetooth LE static pair key for all Bluetooth LE connections.

Command:

AT+BLESETKEY=<static_key>

Response:

OK

Parameter¶

<static_key>: static Bluetooth LE pair key.

Example¶

AT+BLESETKEY=123456

[ESP32 Only] AT+BLEHIDINIT: Bluetooth LE HID Profile Initialization¶

Query Command¶

Function:

Query the initialization status of Bluetooth LE HID profile.

Command:

AT+BLEHIDINIT?

Response:

If Bluetooth LE HID device profile is not initialized, AT will return:

+BLEHIDINIT:0
OK

If Bluetooth LE HID device profile is initialized, AT will return:

+BLEHIDINIT:1
OK

Set Command¶

Function:

Initialize the Bluetooth LE HID profile.

Command:

AT+BLEHIDINIT=<init>

Response:

OK

Parameter¶

<init>:
- 0: deinit Bluetooth LE HID profile
- 1: init Bluetooth LE HID profile

Note¶

The Bluetooth LE HID command cannot be used at the same time with general GATT/GAP commands.

Example¶

AT+BLEHIDINIT=1

[ESP32 Only] AT+BLEHIDKB: Send Bluetooth LE HID Keyboard Information¶

Set Command¶

Function:

Send keyboard information.

Command:

AT+BLEHIDKB=<Modifier_keys>,<key_1>,<key_2>,<key_3>,<key_4>,<key_5>,<key_6>

Response:

OK

Parameters¶

<Modifier_keys>: modifier keys mask
<key_1>: key code 1
<key_2>: key code 2
<key_3>: key code 3
<key_4>: key code 4
<key_5>: key code 5
<key_6>: key code 6

Note¶

For more information about key codes, please refer to the chapter Keyboard/Keypad Page of Universal Serial Bus HID Usage Tables.

Example¶

AT+BLEHIDKB=0,4,0,0,0,0,0   // input the string "a"

[ESP32 Only] AT+BLEHIDMUS: Send Bluetooth LE HID Mouse Information¶

Set Command¶

Function:

Send mouse information.

Command:

AT+BLEHIDMUS=<buttons>,<X_displacement>,<Y_displacement>,<wheel>

Response:

OK

Parameters¶

<buttons>: mouse button
<X_displacement>: X displacement
<Y_displacement>: Y displacement
<wheel>: wheel

Example¶

AT+BLEHIDMUS=0,10,10,0

[ESP32 Only] AT+BLEHIDCONSUMER: Send Bluetooth LE HID Consumer Information¶

Set Command¶

Function:

Send consumer information.

Command:

AT+BLEHIDCONSUMER=<consumer_usage_id>

Response:

OK

Parameter¶

<consumer_usage_id>: consumer ID, such as power, reset, help, volume and so on. See chapter Consumer Page (0x0C) of HID Usage Tables for Universal Serial Bus (USB) for more information.

Example¶

AT+BLEHIDCONSUMER=233   // volume up

[ESP32 Only] AT+BLUFI: Start or Stop BluFi¶

Query Command¶

Function:

Query the status of BluFi.

Command:

AT+BLUFI?

Response:

If BluFi is not started, it will return:

+BLUFI:0
OK

If BluFi is started, it will return:

+BLUFI:1
OK

Set Command¶

Function:

Start or stop BluFi.

Command:

AT+BLUFI=<option>[,<auth floor>]

Response:

OK

Parameter¶

<option>:
- 0: stop BluFi
- 1: start BluFi
<auth floor>: Wi-Fi authentication mode floor. ESP-AT will not connect to the AP whose authmode is lower than this floor.
- 0: OPEN (Default)
- 1: WEP
- 2: WPA_PSK
- 3: WPA2_PSK
- 4: WPA_WPA2_PSK
- 5: WPA2_ENTERPRISE
- 6: WPA3_PSK
- 7: WPA2_WPA3_PSK

Example¶

AT+BLUFI=1

[ESP32 Only] AT+BLUFINAME: Query/Set BluFi Device Name¶

Query Command¶

Function:

Query the BluFi name.

Command:

AT+BLUFINAME?

Response:

+BLUFINAME:<device_name>
OK

Set Command¶

Function:

Set the BluFi device name.

Command:

AT+BLUFINAME=<device_name>

Response:

OK

Parameter¶

<device_name>: the name of BluFi device.

Notes¶

If you need to set BluFi name, please set it before command AT+BLUFI=1. Otherwise, it will use the default name BLUFI_DEVICE.
The maximum length of BluFi name is 29 bytes.

Example¶

AT+BLUFINAME="BLUFI_DEV"
AT+BLUFINAME?

[ESP32 Only] Classic Bluetooth® AT Commands¶

[中文]

ESP32 AT firmware supports Bluetooth® Core Specification Version 5.0.

[ESP32 Only] AT+BTINIT: Classic Bluetooth initialization.
[ESP32 Only] AT+BTNAME: Query/Set Classic Bluetooth device name.
[ESP32 Only] AT+BTSCANMODE: Set Classic Bluetooth scan mode.
[ESP32 Only] AT+BTSTARTDISC: Start Classic Bluetooth discovery.
[ESP32 Only] AT+BTSPPINIT: Classic Bluetooth SPP profile initialization.
[ESP32 Only] AT+BTSPPCONN: Query/Establish SPP connection.
[ESP32 Only] AT+BTSPPDISCONN: End SPP connection.
[ESP32 Only] AT+BTSPPSTART: Start Classic Bluetooth SPP profile.
[ESP32 Only] AT+BTSPPSEND: Send data to remote Classic Bluetooth SPP device.
[ESP32 Only] AT+BTA2DPINIT: Classic Bluetooth A2DP profile initialization.
[ESP32 Only] AT+BTA2DPCONN: Establish A2DP connection.
[ESP32 Only] AT+BTA2DPDISCONN: End A2DP connection.
[ESP32 Only] AT+BTA2DPSRC: Query/Set the audio file URL.
[ESP32 Only] AT+BTA2DPCTRL: Control the audio play.
[ESP32 Only] AT+BTSECPARAM: Query/Set the Classic Bluetooth security parameters.
[ESP32 Only] AT+BTKEYREPLY: Input the Simple Pair Key.
[ESP32 Only] AT+BTPINREPLY: Input the Legacy Pair PIN Code.
[ESP32 Only] AT+BTSECCFM: Reply the confirm value to the peer device in the legacy connection stage.
[ESP32 Only] AT+BTENCDEV: Query Classic Bluetooth encryption device list.
[ESP32 Only] AT+BTENCCLEAR: Clear Classic Bluetooth encryption device list.
[ESP32 Only] AT+BTCOD: Set class of devices.
[ESP32 Only] AT+BTPOWER: Query/Set power of Classic Bluetooth.

[ESP32 Only] AT+BTINIT: Classic Bluetooth Initialization¶

Query Command¶

Function:

Query the initialization status of Classic Bluetooth.

Command:

AT+BTINIT?

Response:

If Classic Bluetooth is initialized, AT will return:

+BTINIT:1
OK

If Classic Bluetooth is not initialized, AT will return:

+BTINIT:0
OK

Set Command¶

Function:

Initialize or deinitialize Classic Bluetooth.

Command:

AT+BTINIT=<init>

Response:

OK

Parameter¶

<init>:
- 0: deinitialize Classic Bluetooth.
- 1: initialize Classic Bluetooth.

Example¶

AT+BTINIT=1

[ESP32 Only] AT+BTNAME: Query/Set Classic Bluetooth Device Name¶

Query Command¶

Function:

Query the Classic Bluetooth device name.

Command:

AT+BTNAME?

Response:

+BTNAME:<device_name>
OK

Set Command¶

Function:

Set the Classic Bluetooth device name.

Command:

AT+BTNAME=<device_name>

Response:

OK

Parameter¶

<device_name>: the Classic Bluetooth device name. The maximum length is 32.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The default Classic Bluetooth device name is “ESP32_AT”.

Example¶

AT+BTNAME="esp_demo"

[ESP32 Only] AT+BTSCANMODE: Set Classic Bluetooth Scan Mode¶

Set Command¶

Function:

Set the scan mode of Classic Bluetooth.

Command:

AT+BTSCANMODE=<scan_mode>

Response:

OK

Parameter¶

<scan_mode>:
- 0: Neither discoverable nor connectable.
- 1: Connectable but not discoverable.
- 2: Both discoverable and connectable.
- 3: Discoverable but not connectable.

Example¶

AT+BTSCANMODE=2   // both discoverable and connectable

[ESP32 Only] AT+BTSTARTDISC: Start Classic Bluetooth Discovery¶

Set Command¶

Function:

Start Classic Bluetooth discovery.

Command:

AT+BTSTARTDISC=<inq_mode>,<inq_len>,<inq_num_rsps>

Response:

+BTSTARTDISC:<bt_addr>,<dev_name>,<major_dev_class>,<minor_dev_class>,<major_srv_class>,<rssi>

OK

Parameters¶

<inq_mode>:
- 0: general inquiry mode.
- 1: limited inquiry mode.
<inq_len>: inquiry duration. Range: 0x01 ~ 0x30.
<inq_num_rsps>: number of inquiry responses that can be received. If you set it to 0, AT will receive an unlimited number of responses.
<bt_addr>: Classic Bluetooth address.
<dev_name>: device name.
<major_dev_class>:
- 0x0: miscellaneous.
- 0x1: computer.
- 0x2: phone (cellular, cordless, pay phone, modem).
- 0x3: LAN, Network Access Point.
- 0x4: audio/video (headset, speaker, stereo, video display, VCR).
- 0x5: peripheral (mouse, joystick, keyboard).
- 0x6: imaging (printer, scanner, camera, display).
- 0x7: wearable.
- 0x8: toy.
- 0x9: health.
- 0x1F: uncategorized device.
<minor_dev_class>: please refer to Minor Device Class field.
<major_srv_class>:
- 0x0: an invalid value.
- 0x1: Limited Discoverable Mode.
- 0x8: positioning (location identification).
- 0x10: networking, such as LAN, Ad hoc.
- 0x20: rendering, such as printing, speakers.
- 0x40: capturing, such as scanner, microphone.
- 0x80: object transfer, such as v-Inbox, v-Folder.
- 0x100: audio, such as speaker, microphone, headerset service.
- 0x200: telephony, such as cordless telephony, modem, headset service.
- 0x400: information, such as WEB-server, WAP-server.
<rssi>: signal strength.

Example¶

AT+BTINIT=1
AT+BTSCANMODE=2
AT+BTSTARTDISC=0,10,10

[ESP32 Only] AT+BTSPPINIT: Classic Bluetooth SPP Profile Initialization¶

Query Command¶

Function:

Query the initialization status of Classic Bluetooth SPP profile.

Command:

AT+BTSPPINIT?

Response:

If Classic Bluetooth SPP profile is initialized, it will return:

+BTSPPINIT:1
OK

If Classic Bluetooth SPP profile is not initialized, it will return:

+BTSPPINIT:0
OK

Set Command¶

Function:

Initialize or deinitialize Classic Bluetooth SPP profile.

Command:

AT+BTSPPINIT=<init>

Response:

OK

Parameter¶

<init>:
- 0: deinitialize Classic Bluetooth SPP profile.
- 1: initialize Classic Bluetooth SPP profile, the role is master.
- 2: initialize Classic Bluetooth SPP profile, the role is slave.

Example¶

AT+BTSPPINIT=1    // master
AT+BTSPPINIT=2    // slave

[ESP32 Only] AT+BTSPPCONN: Query/Establish SPP Connection¶

Query Command¶

Function:

Query Classic Bluetooth SPP connection.

Command:

AT+BTSPPCONN?

Response:

+BTSPPCONN:<conn_index>,<remote_address>
OK

If the connection has not been established, AT will return:

+BTSPPCONN:-1

Set Command¶

Function:

Establish the Classic Bluetooth SPP connection.

Command:

AT+BTSPPCONN=<conn_index>,<sec_mode>,<remote_address>

Response:

OK

If the connection is established successfully, AT will return:

+BTSPPCONN:<conn_index>,<remote_address>

Otherwise, AT will return:

+BTSPPCONN:<conn_index>,-1

Parameters¶

<conn_index>: index of Classic Bluetooth SPP connection. Only 0 is supported for the single connection right now.
<sec_mode>:
- 0x0000: no security.
- 0x0001: authorization required (only needed for out going connection).
- 0x0036: encryption required.
- 0x3000: Man-In-The-Middle protection.
- 0x4000: Min 16 digit for pin code.
<remote_address>: remote Classic Bluetooth SPP device address.

Example¶

AT+BTSPPCONN=0,0,"24:0a:c4:09:34:23"

[ESP32 Only] AT+BTSPPDISCONN: End SPP Connection¶

Execute Command¶

Function:

End the Classic Bluetooth SPP connection.

Command:

AT+BTSPPDISCONN=<conn_index>

Response:

OK

If the command is successful, it will prompt:

+BTSPPDISCONN:<conn_index>,<remote_address>

If the command is fail, it will prompt:

+BTSPPDISCONN:-1

Parameters¶

<conn_index>: index of Classic Bluetooth SPP connection. Only 0 is supported for the single connection right now.
<remote_address>: remote Classic Bluetooth A2DP device address.

Example¶

AT+BTSPPDISCONN=0

[ESP32 Only] AT+BTSPPSEND: Send Data to Remote Classic Bluetooth SPP Device¶

Execute Command¶

Function:

Enter Classic Bluetooth SPP mode.

Command:

AT+BTSPPSEND

Response:

Set Command¶

Function:

Send data to the remote Classic Bluetooth SPP device.

Command:

AT+BTSPPSEND=<conn_index>,<data_len>

Response:

OK

Parameters¶

<conn_index>: index of Classic Bluetooth SPP connection. Only 0 is supported for the single connection right now.
<data_len>: the length of the data which is ready to be sent.

Notes¶

The wrap return is > after this command is executed. Then, the ESP device enters UART Bluetooth passthrough mode. When the packet which only contains +++ is received, the device returns to normal command mode. Please wait for at least one second before sending the next AT command.

Example¶

AT+BTSPPSEND=0,100
AT+BTSPPSEND

[ESP32 Only] AT+BTSPPSTART: Start Classic Bluetooth SPP Profile¶

Execute Command¶

Function:

Start Classic Bluetooth SPP profile.

Command:

AT+BTSPPSTART

Response:

OK

Note¶

During the SPP transmission, AT will not prompt any connection status changes unless bit2 of AT+SYSMSG is 1.

Example¶

AT+BTSPPSTART

[ESP32 Only] AT+BTA2DPINIT: Classic Bluetooth A2DP Profile Initialization¶

Query Command¶

Function:

Query the initialization status of Classic Bluetooth A2DP profile.

Command:

AT+BTA2DPINIT?

Response:

If Classic Bluetooth A2DP profile is initialized, AT will return:

+BTA2DPINIT:1
OK

Otherwise, AT will return:

+BTA2DPINIT:0
OK

Set Command¶

Function:

Initialize or deinitialize Classic Bluetooth A2DP profile.

Command:

AT+BTA2DPINIT=<role>,<init_val>

Response:

OK

Parameters¶

<role>:
- 0: source.
- 1: sink.
<init_val>:
- 0: deinitialize Classic Bluetooth A2DP profile.
- 1: initialize Classic Bluetooth A2DP profile.

Example¶

AT+BTA2DPINIT=0,1

[ESP32 Only] AT+BTA2DPCONN: Query/Establish A2DP Connection¶

Query Command¶

Function:

Query Classic Bluetooth A2DP connection.

Command:

AT+BTA2DPCONN?

Response:

+BTA2DPCONN:<conn_index>,<remote_address>
OK

If the connection has not been established, AT will NOT return the parameter <conn_index> and <remote_address>.

Set Command¶

Function:

Establish the Classic Bluetooth A2DP connection.

Command:

AT+BTA2DPCONN=<conn_index>,<remote_address>

Response:

OK

If the connection is established successfully, it will prompt the message below:

+BTA2DPCONN:<conn_index>,<remote_address>

Otherwise, it will return:

+BTA2DPCONN:<conn_index>,-1

Parameters¶

<conn_index>: index of Classic Bluetooth A2DP connection. Only 0 is supported for the single connection right now.
<remote_address>: remote Classic Bluetooth A2DP device address.

Example¶

AT+BTA2DPCONN=0,0,0,"24:0a:c4:09:34:23"

[ESP32 Only] AT+BTA2DPDISCONN: End A2DP Connection¶

Execute Command¶

Function:

End the Classic Bluetooth A2DP connection.

Command:

AT+BTA2DPDISCONN=<conn_index>

Response:

+BTA2DPDISCONN:<conn_index>,<remote_address>
OK

Parameters¶

<conn_index>: index of Classic Bluetooth A2DP connection. Only 0 is supported for the single connection right now.
<remote_address>: remote Classic Bluetooth A2DP device address.

Example¶

AT+BTA2DPDISCONN=0

[ESP32 Only] AT+BTA2DPSRC: Query/Set the Audio File URL¶

Query Command¶

Function:

Query the audio file URL.

Command:

AT+BTA2DPSRC?

Response:

+BTA2DPSRC:<url>,<type>
OK

Execute Command¶

Function:

Set the audio file URL.

Command:

AT+BTA2DPSRC=<conn_index>,<url>

Response:

OK

Parameters¶

<conn_index>: index of Classic Bluetooth A2DP connection. Only 0 is supported for the single connection right now.
<url>: the path of the source file. HTTP, HTTPS and FLASH are currently supported.
<type>: the type of audio file, such as “mp3”.

Note¶

Only mp3 format is currently supported.

Example¶

AT+BTA2DPSRC=0,"https://dl.espressif.com/dl/audio/ff-16b-2c-44100hz.mp3"
AT+BTA2DPSRC=0,"flash://spiffs/zhifubao.mp3"

[ESP32 Only] AT+BTA2DPCTRL: Control the Audio Play¶

Execute Command¶

Function:

Control the audio play.

Command:

AT+BTA2DPCTRL=<conn_index>,<ctrl>

Response:

OK

Parameters¶

<conn_index>: index of Classic Bluetooth A2DP connection. Only 0 is supported for the single connection right now.
<ctrl>: types of control.
- 0: A2DP Sink, stop play.
- 1: A2DP Sink, start play.
- 2: A2DP Sink, forward.
- 3: A2DP Sink, backward.
- 4: A2DP Sink, fastward start.
- 5: A2DP Sink, fastward stop.
- 0: A2DP Source, stop play.
- 1: A2DP Source, start play.
- 2: A2DP Source, suspend.

Example¶

AT+BTA2DPCTRL=0,1  // start play audio

[ESP32 Only] AT+BTSECPARAM: Query/Set the Classic Bluetooth Security Parameters¶

Query Command¶

Function:

Query Classic Bluetooth security parameters.

Command:

AT+BTSECPARAM?

Response:

+BTSECPARAM:<io_cap>,<pin_type>,<pin_code>
OK

Set Command¶

Function:

Set the Classic Bluetooth security parameters.

Command:

AT+BTSECPARAM=<io_cap>,<pin_type>,<pin_code>

Response:

OK

Parameters¶

<io_cap>: input and output capability.
- 0: DisplayOnly.
- 1: DisplayYesNo.
- 2: KeyboardOnly.
- 3: NoInputNoOutput.
<pin_type>: use variable or fixed PIN.
- 0: variable.
- 1: fixed.
<pin_code>: Legacy Pair PIN Code. Maximum: 16 bytes.

Note¶

If you set the parameter <pin_type> to 0, <pin_code> will be ignored.

Example¶

AT+BTSECPARAM=3,1,"9527"

[ESP32 Only] AT+BTKEYREPLY: Input the Simple Pair Key¶

Execute Command¶

Function:

Input the Simple Pair Key.

Command:

AT+BTKEYREPLY=<conn_index>,<Key>

Response:

OK

Parameters¶

<conn_index>: index of Classic Bluetooth connection. Currently, only 0 is supported for the single connection.
<Key>: the Simple Pair Key.

Example¶

AT+BTKEYREPLY=0,123456

[ESP32 Only] AT+BTPINREPLY: Input the Legacy Pair PIN Code¶

Execute Command¶

Function:

Input the Legacy Pair PIN Code.

Command:

AT+BTPINREPLY=<conn_index>,<Pin>

Response:

OK

Parameters¶

<conn_index>: index of Classic Bluetooth connection. Currently, only 0 is supported for the single connection.
<Pin>: the Legacy Pair PIN Code.

Example¶

AT+BTPINREPLY=0,"6688"

[ESP32 Only] AT+BTSECCFM: Reply the Confirm Value to the Peer Device in the Legacy Connection Stage¶

Execute Command¶

Function:

Reply the confirm value to the peer device in the legacy connection stage.

Command:

AT+BTSECCFM=<conn_index>,<accept>

Response:

OK

Parameters¶

<conn_index>: index of Classic Bluetooth connection. Currently, only 0 is supported for the single connection.
<accept>: reject or accept.
- 0: reject.
- 1: accept.

Example¶

AT+BTSECCFM=0,1

[ESP32 Only] AT+BTENCDEV: Query Classic Bluetooth Encryption Device List¶

Query Command¶

Function:

Query the bound devices.

Command:

AT+BTENCDEV?

Response:

+BTENCDEV:<enc_dev_index>,<mac_address>
OK

Parameters¶

<enc_dev_index>: index of the bound devices.
<mac_address>: MAC address.

Example¶

AT+BTENCDEV?

[ESP32 Only] AT+BTENCCLEAR: Clear Classic Bluetooth Encryption Device List¶

Set Command¶

Function:

Remove a device from the security database list with a specific index.

Command:

AT+BTENCCLEAR=<enc_dev_index>

Response:

OK

Execute Command¶

Function:

Remove all devices from the security database.

Command:

AT+BLEENCCLEAR

Response:

OK

Parameter¶

<enc_dev_index>: index of the bound devices.

Example¶

AT+BTENCCLEAR

[ESP32 Only] AT+BTCOD: Set Class of Devices¶

Set Command¶

Function:

Set the Classic Bluetooth class of devices.

Command:

AT+BTCOD=<major>,<minor>,<service>

Response:

OK

Parameters¶

<major>: major class.
<minor>: minor class.
<service>: service class.

Example¶

AT+BTCOD=6,32,32   // the printer

[ESP32 Only] AT+BTPOWER: Query/Set TX power of Classic Bluetooth¶

Query Command¶

Function:

Query Classic Bluetooth tx power level.

Command:

AT+BTPOWER?

Response:

+BTPOWER:<min_tx_power>,<max_tx_power>
OK

Set Command¶

Function:

Set the Classic Bluetooth tx power.

Command:

AT+BTPOWER=<min_tx_power>,<max_tx_power>

Response:

OK

Parameters¶

<min_tx_power>: The minimum power level. Range: [0,7].
<max_tx_power>: The maximum power level. Range: [0,7].

Example¶

AT+BTPOWER=5,6   // set Classic Bluetooth tx power.

MQTT AT Commands¶

[中文]

AT+MQTTUSERCFG: Set MQTT user configuration
AT+MQTTLONGCLIENTID: Set MQTT client ID
AT+MQTTLONGUSERNAME: Set MQTT username
AT+MQTTLONGPASSWORD: Set MQTT password
AT+MQTTCONNCFG: Set configuration of MQTT connection
AT+MQTTCONN: Connect to MQTT Brokers
AT+MQTTPUB: Publish MQTT Messages in string
AT+MQTTPUBRAW: Publish MQTT messages in binary
AT+MQTTSUB: Subscribe to MQTT topics
AT+MQTTUNSUB: Unsubscribe from MQTT topics
AT+MQTTCLEAN: Close MQTT connections
MQTT AT Error Codes
MQTT AT Notes

AT+MQTTUSERCFG: Set MQTT User Configuration¶

Set Command¶

Function:

Set MQTT User Configuration.

Command:

AT+MQTTUSERCFG=<LinkID>,<scheme>,<"client_id">,<"username">,<"password">,<cert_key_ID>,<CA_ID>,<"path">

Response:

OK

Parameters¶

<LinkID>: currently only supports link ID 0.
<scheme>: MQTT over TLS is not supported due to memory limit on ESP8266, that is to say, this parameter can only be set to 1 or 6.
- 1: MQTT over TCP.
- 2: MQTT over TLS (no certificate verify).
- 3: MQTT over TLS (verify server certificate).
- 4: MQTT over TLS (provide client certificate).
- 5: MQTT over TLS (verify server certificate and provide client certificate).
- 6: MQTT over WebSocket (based on TCP).
- 7: MQTT over WebSocket Secure (based on TLS, no certificate verify).
- 8: MQTT over WebSocket Secure (based on TLS, verify server certificate).
- 9: MQTT over WebSocket Secure (based on TLS, provide client certificate).
- 10: MQTT over WebSocket Secure (based on TLS, verify server certificate and provide client certificate).
<client_id>: MQTT client ID. Maximum length: 256 bytes.
<username>: the username to login to the MQTT broker. Maximum length: 64 bytes.
<password>: the password to login to the MQTT broker. Maximum length: 64 bytes.
<cert_key_ID>: certificate ID. Currently, ESP-AT only supports one certificate for ID 0.
<CA_ID>: CA ID. Currently, ESP-AT only supports one CA for ID 0.
<path>: the path of the resource. Maximum length: 32 bytes.

Note¶

The length of the entire AT command should be less than 256 bytes.

AT+MQTTLONGCLIENTID: Set MQTT Client ID¶

Set Command¶

Function:

Set MQTT Client ID.

Command:

AT+MQTTLONGCLIENTID=<LinkID>,<length>

Response:

OK

>

This response indicates that AT is ready for receiving MQTT Client ID. You should enter the Client ID, and when the Client ID length reaches the <length> value, the system returns:

OK

Parameters¶

<LinkID>: currently only supports link ID 0.
<length>: MQTT client ID length. Range: [1,1024].

Notes¶

The command AT+MQTTUSERCFG can also set MQTT client ID. The differences between the two commands include:
- You can use AT+MQTTLONGCLIENTID to set a relatively long client ID since there is a limitation on the length of the AT+MQTTUSERCFG command.
- You should set AT+MQTTLONGCLIENTID after setting the AT+MQTTUSERCFG command.

AT+MQTTLONGUSERNAME: Set MQTT Username¶

Set Command¶

Function:

Set MQTT username.

Command:

AT+MQTTLONGUSERNAME=<LinkID>,<length>

Response:

OK

>

This response indicates that AT is ready for receiving MQTT username. You should enter the MQTT username, and when the MQTT username length reaches the <length> value, the system returns:

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<length>: MQTT username length. Range: [1,1024].

Notes¶

The command AT+MQTTUSERCFG can also set MQTT username. The differences between the two commands include:
- You can use AT+MQTTLONGUSERNAME to set a relatively long username since there is a limitation on the length of the AT+MQTTUSERCFG command.
- You should set AT+MQTTLONGUSERNAME after setting the command AT+MQTTUSERCFG.

AT+MQTTLONGPASSWORD: Set MQTT Password¶

Set Command¶

Function:

Set MQTT password.

Command:

AT+MQTTLONGPASSWORD=<LinkID>,<length>

Response:

OK

>

This response indicates that AT is ready for receiving MQTT password. You should enter the MQTT password, and when the MQTT password length reaches the <length> value, the system returns:

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<length>: MQTT password length. Range: [1,1024].

Notes¶

The command AT+MQTTUSERCFG can also set MQTT password. The differences between the two commands include:
- You can use AT+MQTTLONGPASSWORD to set a relatively long password since there is a limitation on the length of the AT+MQTTUSERCFG command.
- You should set AT+MQTTLONGPASSWORD after setting the command AT+MQTTUSERCFG.

AT+MQTTCONNCFG: Set Configuration of MQTT Connection¶

Set Command¶

Function:

Set configuration of MQTT Connection.

Command:

AT+MQTTCONNCFG=<LinkID>,<keepalive>,<disable_clean_session>,<"lwt_topic">,<"lwt_msg">,<lwt_qos>,<lwt_retain>

Response:

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<keepalive>: timeout of MQTT ping. Unit: second. Range [0,7200]. The default value is 0, which will be force-changed to 120 s.
<disable_clean_session>: set MQTT clean session. For more details about this parameter, please refer to the section Clean Session in MQTT Version 3.1.1.
- 0: enable clean session.
- 1: disable clean session.
<lwt_topic>: LWT (Last Will and Testament) message topic. Maximum length: 128 bytes.
<lwt_msg>: LWT message. Maximum length: 64 bytes.
<lwt_qos>: LWT QoS, which can be set to 0, 1, or 2. Default: 0.
<lwt_retain>: LWT retain, which can be set to 0 or 1. Default: 0.

AT+MQTTCONN: Connect to MQTT Brokers¶

Query Command¶

Function:

Query the MQTT broker that ESP devices are connected to.

Command:

AT+MQTTCONN?

Response:

+MQTTCONN:<LinkID>,<state>,<scheme><"host">,<port>,<"path">,<reconnect>
OK

Set Command¶

Function:

Connect to an MQTT broker.

Command:

AT+MQTTCONN=<LinkID>,<"host">,<port>,<reconnect>

Response:

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<host>: MQTT broker domain. Maximum length: 128 bytes.
<port>: MQTT broker port. Maximum: port 65535.
<path>: path. Maximum length: 32 bytes.
<reconnect>:
- 0: MQTT will not reconnect automatically.
- 1: MQTT will reconnect automatically. It takes more resources.
<state>: MQTT state.
- 0: MQTT uninitialized.
- 1: already set AT+MQTTUSERCFG.
- 2: already set AT+MQTTCONNCFG.
- 3: connection disconnected.
- 4: connection established.
- 5: connected, but did not subscribe to any topic.
- 6: connected, and subscribed to MQTT topics.
<scheme>:
- 1: MQTT over TCP.
- 2: MQTT over TLS (no certificate verify).
- 3: MQTT over TLS (verify server certificate).
- 4: MQTT over TLS (provide client certificate).
- 5: MQTT over TLS (verify server certificate and provide client certificate).
- 6: MQTT over WebSocket (based on TCP).
- 7: MQTT over WebSocket Secure (based on TLS, verify no certificate).
- 8: MQTT over WebSocket Secure (based on TLS, verify server certificate).
- 9: MQTT over WebSocket Secure (based on TLS, provide client certificate).
- 10: MQTT over WebSocket Secure (based on TLS, verify server certificate and provide client certificate).

AT+MQTTPUB: Publish MQTT Messages in String¶

Set Command¶

Function:

Publish MQTT messages in string to a defined topic. If you need to publish messages in binary, please use the AT+MQTTPUBRAW command.

Command:

AT+MQTTPUB=<LinkID>,<"topic">,<"data">,<qos>,<retain>

Response:

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<topic>: MQTT topic. Maximum length: 128 bytes.
<data>: MQTT message in string.
<qos>: QoS of message, which can be set to 0, 1, or 2. Default: 0.
<retain>: retain flag.

Notes¶

The length of the entire AT command should be less than 256 bytes.
This command cannot send data \0. If you need to send \0, please use the command AT+MQTTPUBRAW instead.

AT+MQTTPUBRAW: Publish MQTT Messages in Binary¶

Set Command¶

Function:

Publish MQTT messages in binary to a defined topic.

Command:

AT+MQTTPUBRAW=<LinkID>,<"topic">,<length>,<qos>,<retain>

Response:

OK
>

The symbol > indicates that AT is ready for receiving serial data, and you can enter the data now. When the requirement of message length determined by the parameter <length> is met, the transmission starts.

If the transmission is successful, AT returns:

+MQTTPUB:OK

Otherwise, it returns:

+MQTTPUB:FAIL

Parameters¶

<LinkID>: only supports link ID 0 currently.
<topic>: MQTT topic. Maximum length: 128 bytes.
<length>: length of MQTT message. The maximum length varies on different ESP devices.
- For ESP32 devices, the maximum length is limited by available memory.
- For ESP8266 devices, the maximum is limited by available memory and the marco MQTT_BUFFER_SIZE_BYTE. The default value of the macro is 512. You can change the max length limitation by setting it in build.py menuconfig. MQTT_BUFFER_SIZE_BYTE equals maximum published data length plus the MQTT header length (depends on topic name length).
<qos>: QoS of the published message, which can be set to 0, 1, or 2. Default is 0.
<retain>: retain flag.

AT+MQTTUNSUB: Unsubscribe from MQTT Topics¶

Set Command¶

Function:

Unsubscribe the client from defined topics. This command can be called multiple times to unsubscribe from different topics.

Command:

AT+MQTTUNSUB=<LinkID>,<"topic">

Response:

OK

If the topic has not been subscribed, AT will prompt:

NO UNSUBSCRIBE

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<topic>: MQTT topic. Maximum length: 128 bytes.

AT+MQTTCLEAN: Close MQTT Connections¶

Set Command¶

Function:

Close the MQTT connection and release the resource.

Command:

AT+MQTTCLEAN=<LinkID>

Response:

OK

Parameter¶

<LinkID>: only supports link ID 0 currently。

MQTT AT Error Codes ¶

The MQTT Error code will be prompted as ERR CODE:0x<%08x>.

Error Type	Error Code
AT_MQTT_NO_CONFIGURED	0x6001
AT_MQTT_NOT_IN_CONFIGURED_STATE	0x6002
AT_MQTT_UNINITIATED_OR_ALREADY_CLEAN	0x6003
AT_MQTT_ALREADY_CONNECTED	0x6004
AT_MQTT_MALLOC_FAILED	0x6005
AT_MQTT_NULL_LINK	0x6006
AT_MQTT_NULL_PARAMTER	0x6007
AT_MQTT_PARAMETER_COUNTS_IS_WRONG	0x6008
AT_MQTT_TLS_CONFIG_ERROR	0x6009
AT_MQTT_PARAM_PREPARE_ERROR	0x600A
AT_MQTT_CLIENT_START_FAILED	0x600B
AT_MQTT_CLIENT_PUBLISH_FAILED	0x600C
AT_MQTT_CLIENT_SUBSCRIBE_FAILED	0x600D
AT_MQTT_CLIENT_UNSUBSCRIBE_FAILED	0x600E
AT_MQTT_CLIENT_DISCONNECT_FAILED	0x600F
AT_MQTT_LINK_ID_READ_FAILED	0x6010
AT_MQTT_LINK_ID_VALUE_IS_WRONG	0x6011
AT_MQTT_SCHEME_READ_FAILED	0x6012
AT_MQTT_SCHEME_VALUE_IS_WRONG	0x6013
AT_MQTT_CLIENT_ID_READ_FAILED	0x6014
AT_MQTT_CLIENT_ID_IS_NULL	0x6015
AT_MQTT_CLIENT_ID_IS_OVERLENGTH	0x6016
AT_MQTT_USERNAME_READ_FAILED	0x6017
AT_MQTT_USERNAME_IS_NULL	0x6018
AT_MQTT_USERNAME_IS_OVERLENGTH	0x6019
AT_MQTT_PASSWORD_READ_FAILED	0x601A
AT_MQTT_PASSWORD_IS_NULL	0x601B
AT_MQTT_PASSWORD_IS_OVERLENGTH	0x601C
AT_MQTT_CERT_KEY_ID_READ_FAILED	0x601D
AT_MQTT_CERT_KEY_ID_VALUE_IS_WRONG	0x601E
AT_MQTT_CA_ID_READ_FAILED	0x601F
AT_MQTT_CA_ID_VALUE_IS_WRONG	0x6020
AT_MQTT_CA_LENGTH_ERROR	0x6021
AT_MQTT_CA_READ_FAILED	0x6022
AT_MQTT_CERT_LENGTH_ERROR	0x6023
AT_MQTT_CERT_READ_FAILED	0x6024
AT_MQTT_KEY_LENGTH_ERROR	0x6025
AT_MQTT_KEY_READ_FAILED	0x6026
AT_MQTT_PATH_READ_FAILED	0x6027
AT_MQTT_PATH_IS_NULL	0x6028
AT_MQTT_PATH_IS_OVERLENGTH	0x6029
AT_MQTT_VERSION_READ_FAILED	0x602A
AT_MQTT_KEEPALIVE_READ_FAILED	0x602B
AT_MQTT_KEEPALIVE_IS_NULL	0x602C
AT_MQTT_KEEPALIVE_VALUE_IS_WRONG	0x602D
AT_MQTT_DISABLE_CLEAN_SESSION_READ_FAILED	0x602E
AT_MQTT_DISABLE_CLEAN_SESSION_VALUE_IS_WRONG	0x602F
AT_MQTT_LWT_TOPIC_READ_FAILED	0x6030
AT_MQTT_LWT_TOPIC_IS_NULL	0x6031
AT_MQTT_LWT_TOPIC_IS_OVERLENGTH	0x6032
AT_MQTT_LWT_MSG_READ_FAILED	0x6033
AT_MQTT_LWT_MSG_IS_NULL	0x6034
AT_MQTT_LWT_MSG_IS_OVERLENGTH	0x6035
AT_MQTT_LWT_QOS_READ_FAILED	0x6036
AT_MQTT_LWT_QOS_VALUE_IS_WRONG	0x6037
AT_MQTT_LWT_RETAIN_READ_FAILED	0x6038
AT_MQTT_LWT_RETAIN_VALUE_IS_WRONG	0x6039
AT_MQTT_HOST_READ_FAILED	0x603A
AT_MQTT_HOST_IS_NULL	0x603B
AT_MQTT_HOST_IS_OVERLENGTH	0x603C
AT_MQTT_PORT_READ_FAILED	0x603D
AT_MQTT_PORT_VALUE_IS_WRONG	0x603E
AT_MQTT_RECONNECT_READ_FAILED	0x603F
AT_MQTT_RECONNECT_VALUE_IS_WRONG	0x6040
AT_MQTT_TOPIC_READ_FAILED	0x6041
AT_MQTT_TOPIC_IS_NULL	0x6042
AT_MQTT_TOPIC_IS_OVERLENGTH	0x6043
AT_MQTT_DATA_READ_FAILED	0x6044
AT_MQTT_DATA_IS_NULL	0x6045
AT_MQTT_DATA_IS_OVERLENGTH	0x6046
AT_MQTT_QOS_READ_FAILED	0x6047
AT_MQTT_QOS_VALUE_IS_WRONG	0x6048
AT_MQTT_RETAIN_READ_FAILED	0x6049
AT_MQTT_RETAIN_VALUE_IS_WRONG	0x604A
AT_MQTT_PUBLISH_LENGTH_READ_FAILED	0x604B
AT_MQTT_PUBLISH_LENGTH_VALUE_IS_WRONG	0x604C
AT_MQTT_RECV_LENGTH_IS_WRONG	0x604D
AT_MQTT_CREATE_SEMA_FAILED	0x604E
AT_MQTT_CREATE_EVENT_GROUP_FAILED	0x604F
AT_MQTT_URI_PARSE_FAILED	0x6050
AT_MQTT_IN_DISCONNECTED_STATE	0x6051
AT_MQTT_HOSTNAME_VERIFY_FAILED	0x6052

MQTT AT Notes ¶

In general, AT MQTT commands responds within 10 s, except the command AT+MQTTCONN. For example, if the router fails to access the Internet, the command AT+MQTTPUB will respond within 10 s. But the command AT+MQTTCONN may need more time due to packet retransmission in a bad network environment.
If the AT+MQTTCONN is based on a TLS connection, the timeout of each packet is 10 s, and the total timeout will be much longer depending on the handshake packets count.
When the MQTT connection ends, it will prompt the message +MQTTDISCONNECTED:<LinkID>.
When the MQTT connection established, it will prompt the message +MQTTCONNECTED:<LinkID>,<scheme>,<"host">,port,<"path">,<reconnect>.

HTTP AT Commands¶

[中文]

AT+HTTPCLIENT: Send HTTP Client Request
AT+HTTPGETSIZE: Get HTTP Resource Size
AT+HTTPCPOST: Post HTTP data of specified length
HTTP AT Error Codes

AT+HTTPCLIENT: Send HTTP Client Request¶

Set Command¶

Command:

AT+HTTPCLIENT=<opt>,<content-type>,<"url">,[<"host">],[<"path">],<transport_type>[,<"data">][,<"http_req_header">][,<"http_req_header">][...]

Response:

+HTTPCLIENT:<size>,<data>

OK

Parameters¶

<opt>: method of HTTP client request.
- 1: HEAD
- 2: GET
- 3: POST
- 4: PUT
- 5: DELETE
<content-type>: data type of HTTP client request.
- 0: application/x-www-form-urlencoded
- 1: application/json
- 2: multipart/form-data
- 3: text/xml
<”url”>: HTTP URL. The parameter can override the <host> and <path> parameters if they are null.
<”host”>: domain name or IP address.
<”path”>: HTTP Path.
<transport_type>: HTTP Client transport type. Default: 1.
- 1: HTTP_TRANSPORT_OVER_TCP
- 2: HTTP_TRANSPORT_OVER_SSL
<”data”>: If <opt> is a POST request, this parameter holds the data you send to the HTTP server. If not, this parameter does not exist, which means there is no need to input a comma to indicate this parameter.
<http_req_header>: you can send more than one request header to the server.

Notes¶

If the url parameter is not null, HTTP client will use it and ignore the host parameter and path parameter; If the url parameter is omited or null string, HTTP client will use host parameter and path parameter.
In some released firmware, HTTP client commands are not supported (see How to understand the differences of each type of module), but you can enable it by ./build.py menuconfig > Component config > AT > AT http command support and build the project (see Build Your Own ESP-AT Project).
For ESP8266 series of devices, if the URL is HTTPS type or <transport_type> parameter is 2, you need to enlarge at_process_task stack size to more than 4096 by configuring ./build.py menuconfig -> Component config -> AT -> The stack size of the AT process task, otherwise ESP8266 will restart due to insufficient stack.

Example¶

// HEAD Request
AT+HTTPCLIENT=1,0,"http://httpbin.org/get","httpbin.org","/get",1

// GET Request
AT+HTTPCLIENT=2,0,"http://httpbin.org/get","httpbin.org","/get",1

// POST Request
AT+HTTPCLIENT=3,0,"http://httpbin.org/post","httpbin.org","/post",1,"field1=value1&field2=value2"

AT+HTTPGETSIZE: Get HTTP Resource Size¶

Set Command¶

Command:

AT+HTTPGETSIZE=<url>

Response:

+HTTPGETSIZE:<size>

OK

Parameters¶

<url>: HTTP URL.
<size>: HTTP resource size.

Note¶

In some released firmware, HTTP client commands are not supported (see How to understand the differences of each type of module), but you can enable it by ./build.py menuconfig > Component config > AT > AT http command support and build the project (see Build Your Own ESP-AT Project).
For ESP8266 series of devices, if the URL is HTTPS type or <transport_type> parameter is 2, you need to enlarge at_process_task stack size to more than 4096 by configuring ./build.py menuconfig -> Component config -> AT -> The stack size of the AT process task, otherwise ESP8266 will restart due to insufficient stack.

Example¶

AT+HTTPGETSIZE="http://www.baidu.com/img/bdlogo.gif"

AT+HTTPCPOST: Post HTTP data of specified length¶

Set Command¶

Command:

AT+HTTPCPOST=<url>,<length>[,<http_req_header_cnt>][,<http_req_header>..<http_req_header>]

Response:

OK
>

The symbol > indicates that AT is ready for receiving serial data, and you can enter the data now. When the requirement of message length determined by the parameter <length> is met, the transmission starts.

If the transmission is successful, AT returns:

SEND OK

Otherwise, it returns:

SEND FAIL

Parameters¶

<url>: HTTP URL.
<length>: HTTP data length to POST. The maximum length is equal to the system allocable heap size.
<http_req_header_cnt>: the number of <http_req_header> parameters.
[<http_req_header>]: you can send more than one request header to the server.

Note¶

For ESP8266 series of devices, if the URL is HTTPS type or <transport_type> parameter is 2, you need to enlarge at_process_task stack size to more than 4096 by configuring ./build.py menuconfig -> Component config -> AT -> The stack size of the AT process task, otherwise ESP8266 will restart due to insufficient stack.

HTTP AT Error Codes ¶

HTTP Client:

HTTP Client Error Code	Description
0x7190	Bad Request
0x7191	Unauthorized
0x7192	Payment Required
0x7193	Forbidden
0x7194	Not Found
0x7195	Method Not Allowed
0x7196	Not Acceptable
0x7197	Proxy Authentication Required
0x7198	Request Timeout
0x7199	Conflict
0x719a	Gone
0x719b	Length Required
0x719c	Precondition Failed
0x719d	Request Entity Too Large
0x719e	Request-URI Too Long
0x719f	Unsupported Media Type
0x71a0	Requested Range Not Satisfiable
0x71a1	Expectation Failed

HTTP Server:

HTTP Server Error Code	Description
0x71f4	Internal Server Error
0x71f5	Not Implemented
0x71f6	Bad Gateway
0x71f7	Service Unavailable
0x71f8	Gateway Timeout
0x71f9	HTTP Version Not Supported

HTTP AT:
- The error code of command AT+HTTPCLIENT will be 0x7000+Standard HTTP Error Code (For more details about Standard HTTP/1.1 Error Code, see RFC 2616).
- For example, if AT gets the HTTP error 404 when calling command AT+HTTPCLIENT, it will respond with error code of 0x7194 (hex(0x7000+404)=0x7194).

[ESP32 Only] Ethernet AT Commands¶

[中文]

Prerequisite
[ESP32 Only] AT+CIPETHMAC: Query/Set the MAC address of the ESP Ethernet.
[ESP32 Only] AT+CIPETH: Query/Set the IP address of the ESP Ethernet.

Prerequisite ¶

Before you run any Ethernet AT Commands, please make the following preparations:

Note

This prerequisite takes ESP32-Ethernet-Kit as an example. If you use other modules or development boards, please refer to corresponding datasheets for RX/TX pins.

Change AT UART pins (because default AT UART pins are in conflict with the Ethernet function pins):
- Open factory_param_data.csv file.
- In the row of module WROVER-32, change uart_tx_pin from GPIO22 to GPIO2, uart_rx_pin from GPIO19 to GPIO4, uart_cts_pin from GPIO15 to GPIO1, and uart_rts_pin from GPIO14 to GPIO1 (flow control is optional and is not used here). See How to Set AT Port Pins for more information.
Enable AT ethernet support. See How to enable ESP-AT Ethernet for more information.
Compile and flash the project onto ESP32-Ethernet-Kit.
Connect your hardware:
- Connect Host MCU (PC with USB to serial converter) to GPIO2 (TX) and GPIO4 (RX) of ESP32-Ethernet-Kit when the flow control function is not enabled.
- Connect ESP32-Ethernet-Kit with Ethernet network.

[ESP32 Only] AT+CIPETHMAC: Query/Set the MAC Address of the ESP Ethernet¶

Query Command¶

Function:

Query the MAC address of the ESP Ethernet.

Command:

AT+CIPETHMAC?

Response:

+CIPETHMAC:<"mac">
OK

Set Command¶

Function:

Set the MAC address of the ESP Ethernet.

Command:

AT+CIPETHMAC=<"mac">

Response:

OK

Parameter¶

<”mac”>: string parameter showing the MAC address of the Ethernet interface.

Notes¶

The default firmware does not support Ethernet AT commands (see How to understand the differences of each type of module), but you can enable it by ./build.py menuconfig > Component config > AT > AT ethernet support and compile the project (see Build Your Own ESP-AT Project).
The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
Please make sure the MAC address of Ethernet interface you set is different from those of other interfaces.
Bit0 of the ESP MAC address CANNOT be 1. For example, a MAC address can be “1a:…” but not “15:…”.
FF:FF:FF:FF:FF:FF and 00:00:00:00:00:00 are invalid MAC addresses and cannot be set.

Example¶

AT+CIPETHMAC="1a:fe:35:98:d4:7b"

[ESP32 Only] AT+CIPETH: Query/Set the IP Address of the the ESP Ethernet¶

Query Command¶

Function:

Query the IP address of the ESP Ethernet.

Command:

AT+CIPETH?

Response:

+CIPETH:ip:<ip>
+CIPETH:gateway:<gateway>
+CIPETH:netmask:<netmask>
OK

Set Command¶

Function:

Set the IP address of the ESP Ethernet.

Command:

AT+CIPETH=<ip>[,<gateway>,<netmask>]

Response:

OK

Parameters¶

<ip>: string parameter showing the IP address of the ESP Ethernet.
[<gateway>]: gateway.
[<netmask>]: netmask.

Notes¶

The default firmware does not support Ethernet AT commands (see How to understand the differences of each type of module), but you can enable it by ./build.py menuconfig > Component config > AT > AT ethernet support and compile the project (see Build Your Own ESP-AT Project).
The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
This Set Command correlates with DHCP commands, such as AT+CWDHCP:
- If static IP is enabled, DHCP will be disabled.
- If DHCP is enabled, static IP will be disabled.
- The last configuration overwrites the previous configuration.

Example¶

AT+CIPETH="192.168.6.100","192.168.6.1","255.255.255.0"

[ESP8266 Only] Signaling Test AT Commands¶

[中文]

AT+FACTPLCP: Send with long or short PLCP (Physical Layer Convergence Procedure)

[ESP8266 Only] AT+FACTPLCP: Send with Long or Short PLCP¶

Set Command¶

Command:

AT+FACTPLCP=<enable>,<tx_with_long>

Response:

OK

Parameters¶

<enable>: Enable or disable manual configuration.
- 0: Disable manual configuration. The default value for the parameter <tx_with_long> will be used.
- 1: Enable manual configuration. The type of PLCP that AT sends depends on <tx_with_long>.
<tx_with_long>: Send with long PLCP or short PLCP.
- 0: Send with short PLCP (default).
- 1: Send with long PLCP.

Web server AT Commands¶

AT+WEBSERVER: Enable/disable Wi-Fi connection configuration via web server.

AT+WEBSERVER: Enable/disable Wi-Fi connection configuration via web server¶

Set Command¶

Command:

AT+WEBSERVER=<enable>,<server_port>,<connection_timeout>

Response:

OK

Parameters¶

<enable>: Enable or disable web server.
- 0: Disable the web server and release related resources.
- 1: Enable web server, which means that you can use WeChat or a browser to configure Wi-Fi connection information.
<server_port>: The web server port number.
<connection_timeout>: The timeout for the every connection. Unit: second. Range:[21,60].

Notes¶

There are two ways to provide the HTML files needed by the web server. One is to use fatfs file system (non ESP8266 chips), and you need to enable AT FS command at this time. The other one is to use embedded files to storge HTML files (default setting).
Please make sure that the max number of open sockets is not less than 12, you may change the number by ./build.py menuconfig > Component config > LWIP > Max bumber of open sockets and compile the project (see Build Your Own ESP-AT Project).
The default firmware does not support web server AT commands (see How to understand the differences of each type of module), but you can enable it by ./build.py menuconfig > Component config > AT > AT WEB Server command support and compile the project (see Build Your Own ESP-AT Project).
For ESP8266 devices, you may need to turn off some unnecessary options to store the necessary html files.
For more examples, please refer to Web Server AT Example.

Example¶

// Enable the web server with port 80, and the timeout for the every connection is 50 seconds:
AT+WEBSERVER=1,80,50

// Disable the web server, the command should be:
AT+WEBSERVER=0

[ESP32 & ESP32-S2 & ESP32-C3] Driver AT Commands¶

[中文]

AT+DRVADC: Read ADC channel value.
AT+DRVPWMINIT: Initialize PWM driver.
AT+DRVPWMDUTY: Set PWM duty.
AT+DRVPWMFADE: Set PWM fade.
AT+DRVI2CINIT: Initialize I2C master driver.
AT+DRVI2CRD: Read I2C data.
AT+DRVI2CWRDATA: Write I2C data.
AT+DRVI2CWRBYTES: Write no more than 4 bytes I2C data.
AT+DRVSPICONFGPIO: Configure SPI GPIO.
AT+DRVSPIINIT: Initialize SPI master driver.
AT+DRVSPIRD: Read SPI data.
AT+DRVSPIWR: Write SPI data.

AT+DRVADC: Read ADC Channel Value¶

Set Command¶

Command:

AT+DRVADC=<channel>,<atten>

Response:

+DRVADC:<raw data>
OK

Parameters¶

<channel>: ADC1 channel. Range: 0 ~ 7. See datasheets for corresponding pins.
<atten>: attenuation.
- 0: 0 dB attenuation gives full-scale voltage 1.1 V.
- 1: 2.5 dB attenuation gives full-scale voltage 1.5 V.
- 2: 6 dB attenuation gives full-scale voltage 2.2 V.
- 3: 11 dB attenuation gives full-scale voltage 3.9 V.
<raw data>: ADC channel value. The voltage value is raw_data/2 ^width * atten.

Notes¶

ESP-AT only supports ADC1.
ESP32 and ESP32-C3 support 12-bit width, and ESP32-S2 only supports 13-bit width.

Example¶

AT+DRVADC=0,0   // ADC1 0 channel, voltage: 0 ~ 1.1 V
+DRVADC:2048    // For ESP32 and ESP32-C3, the voltage is 2048 / 4096 * 1.1 = 0.55
                // For ESP32-S2, the voltage is 2048 / 8192 * 1.1 = 0.264
OK

AT+DRVPWMINIT: Initialize PWM Driver¶

Set Command¶

Command:

AT+DRVPWMINIT=<freq>,<duty_res>,<ch0_gpio>[,...,<ch3_gpio>]

Response:

OK

Parameters¶

<freq>: LEDC timer frequency. Unit: Hz. Range: 1 Hz ~ 8 MHz.
<duty_res>: LEDC channel duty resolution. Range: 0 ~ 20 bits.
<chx_gpio>: LEDC output GPIO number of channel x. For example, if you want to use GPIO16 as channel 0, set <ch0_gpio> to 16.

Notes¶

AT can support a maximum of 4 channels.
The number of channels that you initialize using this command will determine how many channels you can set using other PWM commands, including AT+DRVPWMDUTY and AT+DRVPWMFADE. For example, if you initialize two channels, you can only change the two channels’ PWM duty using command AT+DRVPWMDUTY.
The frequency and the duty resolution are interdependent. See Supported Range of Frequency and Duty Resolutions for more details.

Example¶

AT+DRVPWMINIT=5000,13,17,16,18,19  // set 4 channels; frequency: 5 kHz; duty resolution: 13 bits
AT+DRVPWMINIT=10000,10,17          // only use channel 0, frequency: 10 kHz; duty resolution: 10 bits; other PMW commands can only set one channel

AT+DRVPWMDUTY: Set PWM Duty¶

Set Command¶

Command:

AT+DRVPWMDUTY=<ch0_duty>[,...,<ch3_duty>]

Response:

OK

Parameter¶

<duty>: LEDC channel duty. Range: [0,2 ^{duty_resolution}].

Notes¶

AT can support a maximum of 4 channels.
If you do not want to set <duty> for a specific channel, just omit it.

Example¶

AT+DRVPWMDUTY=255,512   // set channel 0 to duty 255, set channel 1 to duty 512
AT+DRVPWMDUTY=,,0       // set channel 2 to duty 0

AT+DRVPWMFADE: Set PWM Fade¶

Set Command¶

Command:

AT+DRVPWMFADE=<ch0_target_duty>,<ch0_fade_time>[,...,<ch3_target_duty>,<ch3_fade_time>]

Response:

OK

Parameters¶

<target_duty>: target duty of fading. Range: [0, 2 ^{duty_resolution}–1].
<fade_time>: the maximum time of fading. Unit: millisecond.

Notes¶

AT can support a maximum of 4 channels.
If you do not want to set <target_duty> and <fade_time> for a specific channel, just omit them.

Example¶

AT+DRVPWMFADE=,,0,1000           // use one second to change channel 1 duty to 0
AT+DRVPWMFADE=1024,1000,0,2000,  // use one second time to change channel 0 duty to 1024, two seconds to change channel 1 duty to 0

AT+DRVI2CINIT: Initialize I2C Master Driver¶

Set Command¶

Command:

AT+DRVI2CINIT=<num>,<scl_io>,<sda_io>,<clock>

Response:

OK

Parameters¶

<num>: I2C port number. Range: 0 ~ 1. If the following parameters are not set, AT will deinitialize the I2C port.
<scl_io>: GPIO number for I2C SCL signal.
<sda_io>: GPIO number for I2C SDA signal.
<clock>: I2C clock frequency for master mode. Unit: Hz. Maximum: 1 MHz.

Note¶

This command only supports I2C masters.

Example¶

AT+DRVI2CINIT=0,25,26,1000  // initialize I2C0; GPIO25 is SCL; GPIO26 is SDA; I2C clock is 1 kHz
AT+DRVI2CINIT=0             // deinitialize I2C0

AT+DRVI2CRD: Read I2C Data¶

Set Command¶

Command:

AT+DRVI2CRD=<num>,<address>,<length>

Response:

+DRVI2CRD:<read data>
OK

Parameters¶

<num>: I2C port number. Range: 0 ~ 1.
<address>: I2C slave device address.
- 7-bit address: 0 ~ 0x7F.
- 10-bit address: The first seven bits of the first byte are the combination 1111 0XX of which the last two bits (XX) are the two Most Significant Bits (MSBs) of the 10-bit address. For example, if the 10-bit address is 0x2FF (b’1011111111), the input address should be 0x7AFF (b’111101011111111).
<length>: I2C data length. Range: 1 ~ 2048.
<read data>: I2C data.

Note¶

I2C transmission timeout is one second.

Example¶

AT+DRVI2CRD=0,0x34,1     // I2C0 reads one byte data from address 0x34
AT+DRVI2CRD=0,0x7AFF,1   // I2C0 reads one byte data from 10-bit address 0x2FF

// I2C0 reads address 0x34, register address 0x27, read 2 bytes
AT+DRVI2CWRBYTES=0,0x34,1,0x27     // I2C0 first writes device address 0x34, register address 0x27
AT+DRVI2CRD=0,0x34,2               // I2C0 reads 2 bytes

AT+DRVI2CWRDATA: Write I2C Data¶

Set Command¶

Command:

AT+DRVI2CWRDATA=<num>,<address>,<length>

Response:

OK
>

This response indicates that you should enter the data you want to write. When the requirement of data length is met, the data transmission starts.

If the data is transmitted successfully, AT returns:

OK

If the data transmission fails, AT returns:

ERROR

Parameters¶

<num>: I2C port number. Range: 0 ~ 1.
<address>: I2C slave device address.
- 7-bit address: 0 ~ 0x7F.
- 10-bit address: The first seven bits of the first byte are the combination 1111 0XX of which the last two bits (XX) are the two Most Significant Bits (MSBs) of the 10-bit address. For example, if the 10-bit address is 0x2FF (b’1011111111), the input address should be 0x7AFF (b’111101011111111).
<length>: I2C data length. Range: 1 ~ 2048.

Note¶

I2C transmission timeout is one second.

Example¶

AT+DRVI2CWRDATA=0,0x34,10   // I2C0 writes 10 bytes data to address 0x34

AT+DRVI2CWRBYTES: Write No More Than 4 Bytes I2C Data¶

Set Command¶

Command:

AT+DRVI2CWRBYTES=<num>,<address>,<length>,<data>

Response:

OK

Parameters¶

<num>: I2C port number. Range: 0 ~ 1.
<address>: I2C slave device address.
- 7-bit address: 0 ~ 0x7F.
- 10-bit address: The first seven bits of the first byte are the combination 1111 0XX of which the last two bits (XX) are the two Most Significant Bits (MSBs) of the 10-bit address. For example, if the 10-bit address is 0x2FF (b’1011111111), the input address should be 0x7AFF (b’111101011111111).
<length>: the length of the I2C data you want to write. Range: 1 ~ 4 bytes.
<data>: the data of <length> long. Range: 0 ~ 0xFFFFFFFF.

Note¶

I2C transmission timeout is one second.

Example¶

AT+DRVI2CWRBYTES=0,0x34,2,0x1234     // I2C0 writes 2 bytes data 0x1234 to address 0x34
AT+DRVI2CWRBYTES=0,0x7AFF,2,0x1234   // I2C0 writes 2 bytes data 0x1234 to 10-bit address 0x2FF

// I2C0 writes address 0x34; register address: 0x27; data: c0xFF
AT+DRVI2CWRBYTES=0,0x34,2,0x27FF

AT+DRVSPICONFGPIO: Configure SPI GPIO¶

Set Command¶

Command:

AT+DRVSPICONFGPIO=<mosi>,<miso>,<sclk>,<cs>

Response:

OK

Parameters¶

<mosi>: GPIO pin for Master Out Slave In signal.
<miso>: GPIO pin for Master In Slave Out signal, or -1 if not used.
<sclk>: GPIO pin for SPI Clock signal.
<cs>: GPIO pin for slave selection signal, or -1 if not used.

AT+DRVSPIINIT: Initialize SPI Master Driver¶

Set Command¶

Command:

AT+DRVSPIINIT=<clock>,<mode>,<cmd_bit>,<addr_bit>,<dma_chan>[,bits_msb]

Response:

OK

Parameters¶

<clock>: Clock speed, divisors of 80 MHz. Unit: Hz. Maximum: 40 MHz.
<mode>: SPI mode. Range: 0 ~ 3.
<cmd_bit>: Default amount of bits in command phase. Range: 0 ~ 16.
<addr_bit>: Default amount of bits in address phase. Range: 0 ~ 64.
<dma_chan>: Either channel 1 or 2, or 0 in the case when no DMA is required.
<bits_msb>: SPI data format:
- Bit0:
  - 0: Transmit MSB first (default).
  - 1: Transmit LSB first.
- Bit1:
  - 0: Receive data MSB first (default).
  - 1: Receive data LSB first.

Note¶

You should configure SPI GPIO before SPI initialization.

Example¶

AT+DRVSPIINIT=102400,0,0,0,0,3 // SPI clock: 100 kHz; mode: 0; both command and address bits are 0; not use DMA; transmit and receive LSB first
OK
AT+DRVSPIINIT=0   // delete SPI Driver
OK

AT+DRVSPIRD: Read SPI Data¶

Set Command¶

Command:

AT+DRVSPIRD=<data_len>[,<cmd>,<cmd_len>][,<addr>,<addr_len>]

Response:

+DRVSPIRD:<read data>
OK

Parameters¶

<data_len>: length of SPI data you want to read. Range: 1 ~ 4092 bytes.
<cmd>: command data. The length of the data is set in <cmd_len>.
<cmd_len>: command length in this transaction. Range: 0 ~ 2 bytes.
<addr>: command address. The length of the address is set in <addr_len>.
<addr_len>: The address length in this transaction. Range: 0 ~ 4 bytes.

Note¶

If you don’t use DMA, the maximum <data_len> you can set is 64 bytes each time.

Example¶

AT+DRVSPIRD=2  // read 2 bytes data
+DRVI2CREAD:ffff
OK

AT+DRVSPIRD=2,0x03,1,0x001000,3  // read 2 bytes data; <cmd> is 0x03; <cmd_len> is 1 byte; <addr> is 0x1000; <addr_len> is 3 bytes
+DRVI2CREAD:ffff
OK

AT+DRVSPIWR: Write SPI Data¶

Set Command¶

Command:

AT+DRVSPIWR=<data_len>[,<cmd>,<cmd_len>][,<addr>,<addr_len>]

Response:

When <data_len> is larger than 0, AT returns:

OK
>

This response indicates that you should enter the data you want to write. When the requirement of data length is met, the data transmission starts.

If the data is transmitted successfully, AT returns:

OK

When <data_len> is equal to 0, which means AT transmits commands and addresses only, and no SPI data, AT returns:

OK

Parameters¶

<data_len>: SPI data length. Range: 0 ~ 4092.
<cmd>: command data. The length of the data is set in <cmd_len>.
<cmd_len>: command length in this transaction. Range: 0 ~ 2 bytes.
<addr>: command address. The length of the address is set in <addr_len>.
<addr_len>: The address length in this transaction. Range: 0 ~ 4 bytes.

Note¶

If you don’t use DMA, the maximum <data_len> you can set is 64 bytes each time.

Example¶

AT+DRVSPIWR=2  // write 2 bytes data
OK
>              // begin receiving serial data
OK

AT+DRVSPIWR=0,0x03,1,0x001000,3  // write 0 byte data; <cmd> is 0x03; <cmd_len> is 1 byte; <addr> is 0x1000; <addr_len> is 3 bytes
OK

AT Command Set Comparison¶

[中文]

This document lists the differences between the AT commands supported by the old NONOS-AT version and those by the new ESP-AT version that you should pay attention to before migrating from the old to new.

NONOS-AT: Not recommended version for ESP8266 series of chips since its base SDK, ESP8266_NONOS_SDK, is no longer updated.
ESP-AT: Recommended version. It supports all series of chips and a richer set of commands compared with NONOS-AT, such as Bluetooth commands, Bluetooth Low Energy commands, Ethernet commands, driver commands, and so on. For more details about ESP-AT, please refer to What is ESP-AT and AT Binary Lists.

Note

The table below covers all the commands supported by the NONOS-AT, but not all by ESP-AT. See Section AT Command Set for a full list of commands supported by ESP-AT.

The links in the first column of the table point to ESP-AT commands.

AT Command Set Comparison¶
Command	Function	NONOS-AT	ESP-AT
AT	Test AT startup	✅	✅
AT+RST	Restart a module	✅	✅
AT+GMR	Check version information	✅	✅
AT+GSLP	Enter Deep-sleep mode	✅	✅
ATE	AT commands echoing	✅	✅
AT+RESTORE	Restore factory default settings	✅	✅
AT+UART_CUR	Current UART configuration, not saved in flash	✅	✅
AT+UART_DEF	Default UART configuration, saved in flash	✅	✅
AT+SLEEP	Set the sleep mode	✅ 1: light sleep 2: modem sleep	ESP8266 ✅ ESP32 ✅ ESP32-S2 ❌ ¹
AT+WAKEUPGPIO	Wakeup from light sleep on GPIO interrupt	✅	❌ ³ Similar command: AT+SLEEPWKCFG
AT+RFPOWER	Set RF TX Power	✅ Range: [0,82] Unit: 0.25 dBm	✅ ²
AT+RFVDD	Set RF TX power according to VDD33	✅	❌
AT+SYSRAM	Query the remaining space of RAM	✅	✅ Added the parameter of minimum heap size
AT+SYSADC	Read ADC value	✅	❌
AT+SYSIOSETCFG	Set IO working mode	✅	❌
AT+SYSIOGETCFG	Query IO working mode	✅	❌
AT+SYSGPIODIR	Set GPIO direction	✅	❌
AT+SYSGPIOWRITE	Set GPIO output level	✅	❌
AT+SYSGPIOREAD	Read GPIO input level	✅	❌
AT+SYSMSG	Set system prompt info	❌	✅
AT+SYSMSG_CUR	Set system prompt info, not saved in flash	✅	❌ ³ Similar command: AT+SYSMSG
AT+SYSMSG_DEF	Set default system prompt info, saved in flash	✅	❌ ³ Similar command: AT+SYSMSG
AT+CWMODE	Set Wi-Fi mode	❌	✅ Added automatic connection after mode switching
AT+CWMODE_CUR	Set current Wi-Fi mode, not saved in flash	✅	❌ ³ Similar command: AT+CWMODE
AT+CWMODE_DEF	Set default Wi-Fi mode, saved in flash	✅	❌ ³ Similar command: AT+CWMODE
AT+CWJAP	Connect to an AP	✅	✅ Added more functionality
AT+CWJAP_CUR	Connect to an AP, not saved in flash	✅	❌ ³ Similar command: AT+CWJAP
AT+CWJAP_DEF	Connect to an AP, saved in flash	✅	❌ ³ Similar command: AT+CWJAP
AT+CWLAPOPT	Set configuration for AT+CWLAP	✅	✅ Added more functionality
AT+CWLAP	List available APs	✅	✅ Response is different
AT+CWQAP	Disconnect from an AP	✅	✅
AT+CWSAP	Set softAP parameters	❌	✅
AT+CWSAP_CUR	Set softAP parameters, not saved in flash	✅	❌ ³ Similar command: AT+CWSAP
AT+CWSAP_DEF	Set softAP parameters, saved in flash	✅	❌ ³ Similar command: AT+CWSAP
AT+CWLIF	Query info of the station that connects to a softAP	✅	✅
AT+CWDHCP	Set DHCP	❌	✅
AT+CWDHCP_CUR	Set DHCP, not saved in flash	✅	❌ ³ Similar command: AT+CWDHCP
AT+CWDHCP_DEF	Set DHCP, saved in flash	✅	❌ ³ Similar command: AT+CWDHCP
AT+CWDHCPS	Set the IP addresses allocated by an ESP softAP DHCP server	❌	✅
AT+CWDHCPS_CUR	Same as above, but not saved in flash	✅	❌ ³ Similar command: AT+CWDHCPS
AT+CWDHCPS_DEF	Same as above, but saved in flash	✅	❌ ³ Similar command: AT+CWDHCPS
AT+CWAUTOCONN	Connect to an AP automatically when powered on	✅	✅
AT+CIPSTAMAC	Set the MAC address of an ESP station	❌	✅
AT+CIPSTAMAC_CUR	Same as above, but not saved in flash	✅	❌ ³ Similar command: AT+CIPSTAMAC
AT+CIPSTAMAC_DEF	Same as above, but saved in flash	✅	❌ ³ Similar command: AT+CIPSTAMAC
AT+CIPAPMAC	Set the IP address of an ESP softAP	❌	✅
AT+CIPAPMAC_CUR	Same as above, but not saved in flash	✅	❌ ³ Similar command: AT+CIPAPMAC
AT+CIPAPMAC_DEF	Same as above, but saved in flash	✅	❌ ³ Similar command: AT+CIPAPMAC
AT+CIPSTA	Set the IP address of an ESP station	❌	✅
AT+CIPSTA_CUR	Same as above, but not saved in flash	✅	❌ ³ Similar command: AT+CIPSTA
AT+CIPSTA_DEF	Same as above, but saved in flash	✅	❌ ³ Similar command: AT+CIPSTA
AT+CIPAP	Set the IP address of an ESP softAP	❌	✅
AT+CIPAP_CUR	Same as above, but not saved in flash	✅	❌ ³ Similar command: AT+CIPAP
AT+CIPAP_DEF	Same as above, but saved in flash	✅	❌ ³ Similar command: AT+CIPAP
AT+CWSTARTSMART	Start SmartConfig	✅	✅
AT+CWSTOPSMART	Stop SmartConfig	✅	✅
AT+CWSTARTDISCOVER	Enable the mode that an ESP device can be found by WeChat	✅	❌
AT+CWSTOPDISCOVER	Disable the mode that an ESP device can be found by WeChat	✅	❌
AT+WPS	Enable the WPS function	✅	✅
AT+MDNS	Configure the mDNS function	✅	✅
AT+CWJEAP	Connect to a WPA2 Enterprise AP	❌	ESP8266 ❌ ESP32 ✅ ESP32-S2 ❌
AT+CWJEAP_CUR	Same as above, but not saved in flash	✅	❌
AT+CWJEAP_DEF	Same as above, but saved in flash	✅	❌
AT+CWHOSTNAME	Set the host name of an ESP station	✅	✅
AT+CWCOUNTRY	Set the Wi-Fi Country Code	❌	✅
AT+CWCOUNTRY_CUR	Same as above, but not saved in flash	✅	❌ ³ Similar command: AT+CWCOUNTRY
AT+CWCOUNTRY_DEF	Same as above, but saved in flash	✅	❌ ³ Similar command: AT+CWCOUNTRY
AT+CIPSTATUS	Obtain the TCP/UDP/SSL connection status and info	✅	✅
AT+CIPDOMAIN	Resolve a domain name	✅	✅
AT+CIPSTART	Establish a TCP/UDP/SSL connection	✅	✅
AT+CIPSSLSIZE	Set SSL buffer size	✅	❌
AT+CIPSSLCCONF	Set SSL clients	✅	✅ Parameters are different
AT+CIPSEND	Send data	✅	✅
AT+CIPSENDEX	Send data of specified length, or use `\0` to trigger data transmission	✅	✅
AT+CIPSENDBUF	Write data into the TCP-Send-Buffer	✅	❌ ³
AT+CIPBUFRESET	Reset the segment ID count	✅	❌ ³
AT+CIPBUFSTATUS	Query the status of the TCP-Send-Buffer	✅	❌ ³
AT+CIPCHECKSEQ	Query if a specific segment was successfully sent	✅	❌ ³
AT+CIPCLOSEMODE	Set the close mode of TCP connection	✅	❌ ³
AT+CIPCLOSE	Close TCP/UDP/SSL connection	✅	✅
AT+CIFSR	Obtain the local IP address	✅	✅
AT+CIPMUX	Set multiple connections	✅	✅
AT+CIPSERVER	Create a TCP/SSL server	✅ SSL server not supported	✅ SSL server supported for ESP32 and ESP32-S2, not for ESP8266
AT+CIPSERVERMAXCONN	Set the maximum connections allowed by a server	✅	✅
AT+CIPMODE	Set the transmission mode	✅	✅
AT+SAVETRANSLINK	Set whether to enter Wi-Fi Passthrough Mode on power-up	✅	✅
AT+CIPSTO	Set the local TCP server timeout	✅	✅
AT+PING	Ping the remote host	✅	✅
AT+CIUPDATE	Upgrade the firmware through Wi-Fi	✅	✅ More parameters supported
AT+CIPDINFO	Show the remote IP and port with +IPD	✅	✅
AT+CIPRECVMODE	Set TCP Receive Mode	✅	✅
AT+CIPRECVDATA	Get TCP data in passive receive mode	✅	✅ Response is different
AT+CIPRECVLEN	Get TCP data length in passive receive mode	✅	✅
AT+CIPSNTPCFG	Set the time zone and SNTP server	✅	✅ Added more functionality
AT+CIPSNTPTIME	Query SNTP time	✅	✅
AT+CIPDNS	Set DNS server information	❌	✅
AT+CIPDNS_CUR	Same as above, but not saved in flash	✅	❌ ³ Similar command: AT+CIPDNS
AT+CIPDNS_DEF	Same as above, but saved in flash	✅	❌ ³ Similar command: AT+CIPDNS
AT+SYSFLASH	Set user partitions in flash	❌	✅

Note 1: AT+SLEEP in ESP-AT:

ESP8266 and ESP32 ✅

1: modem sleep by DTIM

2: light sleep

3: modem sleep by listen interval

ESP32-S2 ❌

Note 2: AT+RFPOWER in ESP-AT:

ESP8266 ✅. Range: [40,82]. Unit: 0.25 dBm

ESP32 ✅. Range: [40,78]. Unit: 0.25 dBm. Support Bluetooth LE.

ESP32-S2 ✅. Range: [40,78]. Unit: 0.25 dBm

Note 3: This command will not be added to the ESP-AT version.

It is strongly recommended to read the following sections for some common information on AT commands before you dive into the details of each command.

AT Command Types
AT Commands with Configuration Saved in the Flash
AT Messages

AT Command Types ¶

Generic AT command has four types:

Type	Command Format	Description
Test Command	AT+<CommamdName>=?	Query the Set Commands’ internal parameters and their range of values.
Query Command	AT+<CommamdName>?	Return the current value of parameters.
Set Command	AT+<CommamdName>=<…>	Set the value of user-defined parameters in commands, and run these commands.
Execute Command	AT+<CommamdName>	Run commands with no user-defined parameters.

Not all AT commands support all of the four types mentioned above.
Currently, only strings and integer numbers are supported as input parameters in AT commands.
Angle brackets < > designate parameters that can not be omitted.
Square brackets [ ] designate optional parameters that can be omitted. The default value of the parameter will be used instead when you omit it. Below are examples of entering the command AT+CWJAP with some parameters omitted.
```
AT+CWJAP="ssid","password"
AT+CWJAP="ssid","password","11:22:33:44:55:66"
```
If the parameter you want to omit is followed by a parameter(s), you must give a , to indicate it.
```
AT+CWJAP="ssid","password",,1
```
String values need to be included in double quotation marks.
```
AT+CWSAP="ESP756290","21030826",1,4
```
Escape character syntax is needed if a string contains special characters, such as ,, ", or \:
- \\: escape the backslash itself
- \,: escape comma which is not used to separate each parameter
- \": escape double quotation mark which is not used to mark string input
- \<any>: escape <any> character means that drop backslash symbol and only use <any> character
Escape is needed in AT commands only, not elsewhere. For example, when AT command port prints > and wait for your input, the input does not need to be escaped.
```
AT+CWJAP="comma\,backslash\\ssid","1234567890"
AT+MQTTPUB=0,"topic","\"{\"sensor\":012}\"",1,0
```
The default baud rate of AT command is 115200.
The length of each AT command should be no more than 256 bytes.
AT commands end with a new-line (CR-LF), so the serial tool should be set to “New Line Mode”.
Definitions of AT command error codes are provided in AT API Reference:

AT Commands with Configuration Saved in the Flash ¶

Configuration settings entered by the following AT Commands will always be saved in the flash NVS Area, so they can be automatically restored on reset:

AT+UART_DEF: AT+UART_DEF=115200,8,1,0,3
AT+SAVETRANSLINK: AT+SAVETRANSLINK=1,"192.168.6.10",1001
AT+CWAUTOCONN: AT+CWAUTOCONN=1

Saving of configuration settings by several other commands can be switched on or off with AT+SYSSTORE command, which is mentioned in the Note section of these commands.

AT Messages ¶

There are two types of ESP-AT messages returned from the ESP-AT command port:

ESP-AT Response Messages (passive)

Each ESP-AT command input returns response messages to tell the sender the result of the ESP-AT command.

ESP-AT Response Messages¶
AT Response Messages	Description
OK	AT command process done and return OK
ERROR	AT command error or error occurred during the execution
SEND OK	Data has been sent to the protocol stack (specific to AT+CIPSEND and AT+CIPSENDEX command). It doesn’t mean that the data has been sent to the opposite end
SEND FAIL	Error occurred during sending the data to the protocol stack (specific to AT+CIPSEND and AT+CIPSENDEX command
+<Command Name>:`...`	Response to the sender that describes AT command process results in details

ESP-AT Message Reports (active)

ESP-AT will report important state changes or messages in the system.

ESP-AT Message Reports¶
ESP-AT Message Report	Description
ready	The ESP-AT firmware is ready
busy p…	Busy processing. The system is in process of handling the previous command, thus CANNOT accept the new input
ERR CODE:`<0x%08x>`	Error code for different commands
Will force to restart!!!	Module restart right now
smartconfig type:`<xxx>`	Smartconfig type
Smart get wifi info	Smartconfig has got the SSID and PASSWORD information
smartconfig connected wifi	Smartconfig done. ESP-AT has connected to the Wi-Fi
WIFI CONNECTED	Wi-Fi station interface has connected to an AP
WIFI GOT IP	Wi-Fi station interface has got the IPv4 address
WIFI GOT IPv6 LL	Wi-Fi station interface has got the IPv6 LinkLocal address
WIFI GOT IPv6 GL	Wi-Fi station interface has got the IPv6 Global address
WIFI DISCONNECT	Wi-Fi station interface has disconnected from an AP
+ETH_CONNECTED	Ethernet interface has connected
+ETH_GOT_IP	Ethernet interface has got the IPv4 address
+ETH_DISCONNECTED	Ethernet interface has disconnected
[<conn_id>,]CONNECT	A network connection of which ID is `<conn_id>` is established (ID=0 by default)
[<conn_id>,]CLOSED	A network connection of which ID is `<conn_id>` ends (ID=0 by default)
+LINK_CONN	Detailed connection information of TCP/UDP/SSL
+STA_CONNECTED: <sta_mac>	A station has connected to the Wi-Fi softAP interface of ESP-AT
+DIST_STA_IP: <sta_mac>,<sta_ip>	The Wi-Fi softAP interface of ESP-AT distributes an IP address to the station
+STA_DISCONNECTED: <sta_mac>	A station disconnected from the Wi-Fi softAP interface of ESP-AT
>	ESP-AT is waiting for more data to be received
Recv `<xxx>` bytes	ESP-AT has already received `<xxx>` bytes from the ESP-AT command port
+IPD	ESP-AT received the data from the network
SEND Canceled	Cancel to send in Wi-Fi normal sending mode
Have `<xxx>` Connections	Has reached the maximum connection counts for server
+QUITT	ESP-AT quits from the Wi-Fi Passthrough Mode
NO CERT FOUND	No valid device certificate found in custom partition
NO PRVT_KEY FOUND	No valid private key found in custom partition
NO CA FOUND	No valid CA certificate found in custom partition
+MQTTCONNECTED	MQTT connected to the broker
+MQTTDISCONNECTED	MQTT disconnected from the broker
+MQTTSUBRECV	MQTT received the data from the broker
+MQTTPUB:FAIL	MQTT failed to publish data
+MQTTPUB:OK	MQTT publish data done
+BLECONN	A Bluetooth LE connection established
+BLEDISCONN	A Bluetooth LE connection ends
+READ	A read operation from Bluetooth LE connection
+WRITE	A write operation from Bluetooth LE connection
+NOTIFY	A notification from Bluetooth LE connection
+INDICATE	An indication from Bluetooth LE connection
+BLESECNTFYKEY	Bluetooth LE SMP key
+BLESECREQ:<conn_index>	Received encryption request which index is <conn_index>
+BLEAUTHCMPL:<conn_index>,<enc_result>	Bluetooth LE SMP pairing completed

AT Command Examples¶

[中文]

TCP/IP AT Examples¶

Example 1. ESP as a TCP Client in Single Connection
Example 2. ESP as a TCP Server in Multiple Connections
Example 3. UDP Transmission
Example 4. UART-Wi-Fi Passthrough Transmission

Example 1. ESP as a TCP Client in Single Connection ¶

Set the Wi-Fi mode:

Command:
AT+CWMODE=3                  // SoftAP+Station mode

Response:
OK

Connect to the router:

AT+CWJAP="SSID","password"               // SSID and password of router

Response:
OK

Query the device’s IP:

AT+CIFSR

Response:
192.168.3.106                            // device got an IP from router

Connect the PC to the same router which ESP is connected to. Use a network tool on the PC to create a TCP server. For example, the TCP server on PC is 192.168.3.116, port 8080.

ESP is connected to the TCP server as a client:

AT+CIPSTART="TCP","192.168.3.116",8080   // protocol、server IP & port

Send data:
```
AT+CIPSEND=4             // set date length which will be sent, such as 4 bytes
>TEST                     // enter the data, no CR

Response:
SEND OK
```
Note： If the number of bytes inputted are more than the length (n) set by AT+CIPSEND, the system will reply busy, and send the first n bytes. And after sending the first n bytes, the system will reply SEND OK.

Receive data:

+IPD,n:xxxxxxxxxx               // received n bytes, data=xxxxxxxxxxx

Example 2. ESP as a TCP Server in Multiple Connections ¶

When ESP works as a TCP server, multiple connections should be enabled; that is to say, there should be more than one client connecting to ESP.
Below is an example showing how a TCP server is established when ESP works in the SoftAP mode. If ESP works as a Station, set up a server in the same way after connecting ESP to the router.

Set the Wi-Fi mode:

Command:
AT+CWMODE=3                  // SoftAP+Station mode

Response:
OK

Enable multiple connections.
```
AT+CIPMUX=1

Response:
OK
```

Set up a TCP server.

AT+CIPSERVER=1                           // default port = 333

Response:
OK

Connect the PC to the ESP SoftAP.
Using a network tool on PC to create a TCP client and connect to the TCP server that ESP created.
Notice:
When ESP works as a TCP server, there is a timeout mechanism. If the TCP client is connected to the ESP TCP server, while there is no data transmission for a period of time, the server will disconnect from the client. To avoid such a problem, please set up a data transmission cycle every two seconds.

Send data:

// ID number of the first connection is defaulted to be 0
AT+CIPSEND=0,4             // send 4 bytes to connection NO.0
>TEST                      // enter the data, no CR

Response:
SEND OK

Note： If the number of bytes inputted are more than the length (n) set by AT+CIPSEND, the system will reply busy, and send the first n bytes. And after sending the first n bytes, the system will reply SEND OK.

Receive data:

+IPD,0,n:xxxxxxxxxx               // received n bytes, data=xxxxxxxxxxx

Close the TCP connection.
```
AT+CIPCLOSE=0

Response:
0,CLOSED
OK
```

Example 3. UDP Transmission ¶

Set the Wi-Fi mode:

Command:
AT+CWMODE=3                  // SoftAP+Station mode

Response:
OK

Connect to the router:

AT+CWJAP="SSID","password"               // SSID and password of router

Response:
OK

Query the device’s IP:

AT+CIFSR

Response:
+CIFSR:STAIP,"192.168.101.104"              // device got an IP from router

Connect the PC to the same router which ESP is connected to. Use a network tool on the PC to create UDP transmission. For example, the PC’s IP address is 192.168.101.116, port 8080.
Below are two examples of UDP transmission.

Example 3.1. UDP Transmission with Fixed Remote IP and Port¶

In UDP transmission, whether the remote IP and port are fixed or not is determined by the last parameter of AT+CIPSTART. 0 means that the remote IP and port are fixed and cannot be changed. A specific ID is given to such a connection, ensuring that the data sender and receiver will not be replaced by other devices.

Enable multiple connections:
```
AT+CIPMUX=1

Response:
OK
```
Create a UDP transmission, with the ID being 4, for example.
```
AT+CIPSTART=4,"UDP","192.168.101.110",8080,1112,0

Response:
4,CONNECT
OK
```
Notes:
- "192.168.101.110" and 8080 are the remote IP and port of UDP transmission on the remote side, i.e., the UDP configuration set by PC.
- 1112 is the local port number of ESP. Users can define this port number. A random port will be used if this parameter is not set.
- 0 means that the remote IP and port are fixed and cannot be changed. For example, if another PC also creates a UDP entity and sends data to ESP port 1112, ESP can receive the data sent from UDP port 1112. But when data are sent using AT command AT+CIPSEND=4,X, it will still be sent to the first PC end. If parameter 0 is not used, the data will be sent to the new PC.
Send data:
```
AT+CIPSEND=4,7              // send 7 bytes to transmission NO.4
>UDPtest                    // enter the data, no CR

Response:
SEND OK
```
Note： If the number of bytes inputted are more than the length (n) set by AT+CIPSEND, the system will reply busy, and send the first n bytes. And after sending the first n bytes, the system will reply SEND OK.

Receive data:

+IPD,4,n:xxxxxxxxxx               // received n bytes, data=xxxxxxxxxxx

Close UDP transmission No.4
```
AT+CIPCLOSE=4

Response:
4,CLOSED
OK
```

Example 3.2. UDP Transmission with Changeable Remote IP and Port¶

Create a UDP transmission with the last parameter being 2.
```
AT+CIPSTART="UDP","192.168.101.110",8080,1112,2

Response:
CONNECT
OK
```
Notes:
- "192.168.101.110" and 8080 here refer to the IP and port of the remote UDP transmission terminal which is created on a PC in above Example 2.
- 1112 is the local port of ESP. Users can define this port. A random port will be opened if this parameter is not set.
- 2 means the means the opposite terminal of UDP transmission can be changed. The remote IP and port will be automatically changed to those of the last UDP connection to ESP.
Send data:
```
AT+CIPSEND=7                // send 7 bytes 
>UDPtest                    // enter the data, no CR

Response:
SEND OK
```
Note： If the number of bytes inputted are more than the length (n) set by AT+CIPSEND, the system will reply busy, and send the first n bytes. And after sending the first n bytes, the system will reply SEND OK.

If you want to send data to any other UDP terminals, please designate the IP and port of the target terminal in the command.

AT+CIPSEND=6,"192.168.101.111",1000          // send six bytes
>abcdef                                      // enter the data, no CR

Response:
SEND OK

Receive data:

+IPD,n:xxxxxxxxxx               // received n bytes, data=xxxxxxxxxxx

Close UDP transmission.
```
AT+CIPCLOSE

Response:
CLOSED
OK
```

Example 4. UART-Wi-Fi Passthrough Transmission ¶

ESP-AT supports UART-Wi-Fi passthrough transmission only when ESP works as a TCP client in single connection or UDP transmission.

Example 4.1. ESP as a TCP Client in UART-Wi-Fi Passthrough (Single Connection Mode)¶

Set the Wi-Fi mode:

Command:
AT+CWMODE=3                  // SoftAP+Station mode

Response:
OK

Connect to the router:

AT+CWJAP="SSID","password"               // SSID and password of router

Response:
OK

Query the device’s IP:

AT+CIFSR

Response:
+CIFSR:STAIP,"192.168.101.105"              // device got an IP from router

Connect the PC to the same router which ESP is connected to. Use a network tool on the PC to create a TCP server. For example, the PC’s IP address is 192.168.101.110, port 8080.

Connect the ESP device to the TCP server as a TCP client.

AT+CIPSTART="TCP","192.168.101.110",8080

Response:
CONNECT
OK

Enable the UART-WiFi transmission mode.
```
AT+CIPMODE=1

Response:
OK
```

Send data.

AT+CIPSEND                

Response:
>                // From now on, data received from UART will be transparent transmitted to server

Stop sending data.
When receiving a packet that contains only +++, the UART-WiFi passthrough transmission process will be stopped. Then please wait at least 1 second before sending next AT command.
Please be noted that if you input +++ directly by typing, the +++, may not be recognised as three consecutive + because of the Prolonged time when typing.
Notice:
The aim of ending the packet with +++ is to exit transparent transmission and to accept normal AT commands, while TCP still remains connected. However, users can also deploy command AT+CIPSEND to go back into transparent transmission.
Exit the UART-WiFi passthrough mode.
```
AT+CIPMODE=0

Response:
OK
```
Close the TCP connection.

AT+CIPCLOSE

Response:
CLOSED
OK

Example 4.2. UDP Transmission in UART-Wi-Fi Passthrough Mode ¶

Here is an example of the ESP working as a SoftAP in UDP transparent transmission.

Set the Wi-Fi mode:

Command:
AT+CWMODE=3                  // SoftAP+Station mode

Response:
OK

Connect the PC to the ESP SoftAP.
Use a network tool on PC to create a UDP endpoint. For example, the PC’s IP address is 192.168.4.2 and the port is 1001.
Create a UDP transmission between ESP32 and the PC with a fixed remote IP and port.
```
AT+CIPSTART="UDP","192.168.4.2",1001,2233,0

Response:
CONNECT
OK
```
Enable the UART-WiFi transmission mode.
```
AT+CIPMODE=1

Response:
OK
```

Send data.

AT+CIPSEND                

Response:
>                // From now on, data received from UART will be transparent transmitted to server

Stop sending data.
When receiving a packet that contains only +++, the UART-WiFi passthrough transmission process will be stopped. Then please wait at least 1 second before sending next AT command.
Please be noted that if you input +++ directly by typing, the +++, may not be recognised as three consecutive + because of the Prolonged time when typing.
Notice:
The aim of ending the packet with +++ is to exit transparent transmission and to accept normal AT commands, while TCP still remains connected. However, users can also deploy command AT+CIPSEND to go back into transparent transmission.
Exit the UART-WiFi passthrough mode.
```
AT+CIPMODE=0

Response:
OK
```
Close the UDP transmission.
```
AT+CIPCLOSE

Response:
CLOSED
OK
```

[ESP32 Only] BLE AT Examples¶

Example 1. [ESP32 Only] BLE AT Examples
Example 2. [ESP32 Only] iBeacon Examples
Example 3. [ESP32 Only] UART-BLE Passthrough Mode

Example 1. [ESP32 Only] BLE AT Example ¶

Below is an example of using two ESP32 modules, one as a BLE server (hereafter named “ESP32 Server”), the other one as a BLE client (hereafter named “ESP32 Client”). The example shows how to use BLE functions with AT commands.
Notice:

The ESP32 Server needs to download a “service bin” into Flash to provide BLE services.
- To learn how to generate a “service bin”, please refer to esp-at/tools/readme.md.
- The download address of the “service bin” is the address of “ble_data” in esp-at/partitions_at.csv.

BLE initialization:

ESP32 Server:

 Command:
 AT+BLEINIT=2                              // server role

 Response:
 OK

ESP32 Client:

 Command:
 AT+BLEINIT=1                              // client role

 Response:
 OK

Establish BLE connection:

ESP32 Server:
(1) Query the BLE address. For example, its address is “24:0a:c4:03:f4:d6”.
```
 Command:
 AT+BLEADDR?                              // get server's BLE address

 Response:
 +BLEADDR:24:0a:c4:03:f4:d6
 OK
```
(2) Start advertising.
```
 Command:
 AT+BLEADVSTART

 Response:
 OK
```
ESP32 Client:
(1) Start scanning.
```
 Command:
 AT+BLESCAN=1,3

 Response:
 +BLESCAN:<BLE address>,<rssi>,<adv_data>,<scan_rsp_data>
 OK
```
(2) Establish the BLE connection, when the server is scanned successfully.
```
 AT+BLECONN=0,"24:0a:c4:03:f4:d6"

 Response:
 OK
 +BLECONN:0,"24:0a:c4:03:f4:d6"
```
Notes:
- If the BLE connection is established successfully, it will prompt +BLECONN:<conn_index>,<remote_BLE_address>
- If the BLE connection is broken, it will prompt +BLEDISCONN:<conn_index>,<remote_BLE_address>
Read/Write a characteristic:

ESP32 Server:
(1) Create services.
```
 AT+BLEGATTSSRVCRE

 Response:
 OK
```
(2) Start services.
```
 AT+BLEGATTSSRVSTART

 Response:
 OK
```
(3) Discover characteristics.
```
 AT+BLEGATTSCHAR?          

 Response:
 +BLEGATTSCHAR:"char",1,1,0xC300
 +BLEGATTSCHAR:"desc",1,1,1
 +BLEGATTSCHAR:"char",1,2,0xC301
 +BLEGATTSCHAR:"desc",1,2,1
 +BLEGATTSCHAR:"char",1,3,0xC302
 +BLEGATTSCHAR:"desc",1,3,1
 OK
```
ESP32 Client:
(1) Discover services.
```
 AT+BLEGATTCPRIMSRV=0   

 Response:
 +BLEGATTCPRIMSRV:0,1,0x1801,1
 +BLEGATTCPRIMSRV:0,2,0x1800,1
 +BLEGATTCPRIMSRV:0,3,0xA002,1
 OK
```
Notice:
- When discovering services, the ESP32 Client will get two more default services (UUID:0x1800 and 0x1801) than what the ESP32 Server will get.
- So, for the same service, the <srv_index> received by the ESP32 Client equals the <srv_index> received by ESP32 Server + 2.
- For example, the <srv_index> of the above-mentioned service, 0xA002, is 3 when the ESP32 Client is in the process of discovering services. But if the ESP32 Server tries to discover it with command AT+BLEGATTSSRV?, the <srv_index> will be 1.
(2) Discover characteristics.
```
 AT+BLEGATTCCHAR=0,3

 Response:
 +BLEGATTCCHAR:"char",0,3,1,0xC300,2
 +BLEGATTCCHAR:"desc",0,3,1,1,0x2901
 +BLEGATTCCHAR:"char",0,3,2,0xC301,2
 +BLEGATTCCHAR:"desc",0,3,2,1,0x2901
 +BLEGATTCCHAR:"char",0,3,3,0xC302,8
 +BLEGATTCCHAR:"desc",0,3,3,1,0x2901
 +BLEGATTCCHAR:"char",0,3,4,0xC303,4
 +BLEGATTCCHAR:"desc",0,3,4,1,0x2901
 +BLEGATTCCHAR:"char",0,3,5,0xC304,8
 +BLEGATTCCHAR:"char",0,3,6,0xC305,16
 +BLEGATTCCHAR:"desc",0,3,6,1,0x2902
 +BLEGATTCCHAR:"char",0,3,7,0xC306,32
 +BLEGATTCCHAR:"desc",0,3,7,1,0x2902
 OK  
```
(3) Read a characteristic. Please note that the target characteristic’s property has to support the read operation.
```
 AT+BLEGATTCRD=0,3,1

 Response:
 +BLEGATTCRD:0,1,30
 OK
```
Note:
- If the ESP32 Client reads the characteristic successfully, message +READ:<conn_index>,<remote BLE address> will be prompted on the ESP32 Server side.
(4) Write a characteristic. Please note that the target characteristic’s property has to support the write operation.
```
 AT+BLEGATTCWR=0,3,3,,2

 Response:
 >       // waiting for data
 OK
```
Note:
- If the ESP32 Client writes the characteristic successfully, message +WRITE:<conn_index>,<srv_index>,<char_index>,[<desc_index>],<len>,<value> will be prompted on the ESP32 Server side.
Notify of a characteristic:

ESP32 Client:
(1) Configure the characteristic’s descriptor. Please note that the target characteristic’s property has to support notifications.
```
 AT+BLEGATTCWR=0,3,6,1,2       

 Response:
 >       // waiting for data
 OK
```
Note:
- If the ESP32 Client writes the descriptor successfully, message +WRITE:<conn_index>,<srv_index>,<char_index>,<desc_index>,<len>,<value> will be prompted on the ESP32 Server side.
ESP32 Server:
(1) Notify of a characteristic. Please note that the target characteristic’s property has to support notifications.
```
 AT+BLEGATTSNTFY=0,1,6,3

 Response:
 >       // waiting for data
 OK
```
Note:
- If the ESP32 Client receives the notification, it will prompt message +NOTIFY:<conn_index>,<srv_index>,<char_index>,<len>,<value>.
- For the same service, the <srv_index> on the ESP32 Client side equals the <srv_index> on the ESP32 Server side + 2.
Indicate a characteristic:

ESP32 Client:
(1) Configure the characteristic’s descriptor. Please note that the target characteristic’s property has to support the indicate operation.
```
 AT+BLEGATTCWR=0,3,7,1,2       

 Response:
 >       // waiting for data
 OK
```
Note:
- If the ESP32 Client writes the descriptor successfully, message +WRITE:<conn_index>,<srv_index>,<char_index>,<desc_index>,<len>,<value> will be prompted on the ESP32 Server side.
ESP32 Server:
(1) Indicate characteristic. Please note that the target characteristic’s property has to support the indicate operation.
```
 AT+BLEGATTSIND=0,1,7,3

 Response:
 >       // waiting for data
 OK
```
Note:
- If the ESP32 Client receives the indication, it will prompt message +INDICATE:<conn_index>,<srv_index>,<char_index>,<len>,<value>
- For the same service, the <srv_index> on the ESP32 Client side equals the <srv_index> on the ESP32 Server side + 2.

Example 2. [ESP32 Only] iBeacon Examples ¶

The following demonstrates two examples of iBeacon for ESP32 modules:

ESP32 advertising iBeacons, which can be discovered by the “Shake Nearby” function of WeChat.
ESP32 scanning iBeacons.

This is the structure of iBeacon Frame.

Type	Length (byte)	Description
iBeacon prefix	9	02 01 06 1A FF 4C 00 02 15
Proximity UUID	16	Used to identify vendor
Major	2	Used to identify store
Minor	2	Used to identify the location of a specific Beacon within a store
TX power	1	Used to calculate the distance between the ESP32 device and the phone

Example 2.1. ESP32 Device Advertising iBeacons¶

Initialize the role of the ESP32 device as a BLE server:

AT+BLEINIT=2                              // server role  

Response：
OK

Start advertising. Configure the parameters of the iBeacon advertisement as the following table shows:

Type	Content
iBeacon prefix	02 01 06 1A FF 4C 00 02 15
Proximity UUID	FDA50693-A4E2-4FB1-AFCF-C6EB07647825
Major	27 B7
Minor	F2 06
TX power	C5

The AT command should be as below:

```
AT+BLEADVDATA="0201061aff4c000215fda50693a4e24fb1afcfc6eb0764782527b7f206c5"

OK

AT+BLEADVSTART               // Start advertising

OK
```

Open WeChat on your mobile phone and then select “Shake Nearby” to discover the ESP32 device that is advertising. avatar

Example 2.2. ESP32 Device Scanning for iBeacons¶

Not only can the ESP32 device transmits iBeacons, but it can also work as a BLE client that scans for iBeacons and gets the advertisement data which can then be parsed by the host MCU.
Notice:
If the ESP32 device has already been initialized as a BLE server, you need to call AT+BLEINIT=0 to de-init it first, and then re-init it as a BLE client.

Initialize the role of the ESP32 device as a BLE client:

AT+BLEINIT=1                              // client role 

Response：
OK

Enable a scanning for three seconds:
```
AT+BLESCAN=1,3

Response：
OK
```

You will get a scanning result that looks like:

```
+BLESCAN:24:0a:c4:02:10:0e,-33,0201061aff4c000215fda50693a4e24fb1afcfc6eb0764782527b7f206c5,
+BLESCAN:24:0a:c4:01:4d:fe,-74,02010207097a4f68664b43020aeb051220004000,
+BLESCAN:24:0a:c4:02:10:0e,-33,0201061aff4c000215fda50693a4e24fb1afcfc6eb0764782527b7f206c5,
```

Example 3. [ESP32 Only] UART-BLE Passthrough Mode ¶

Below is an example of using two ESP32 modules, one as a BLE server (hereafter named “ESP32 Server”), the other one as a BLE client (hereafter named “ESP32 Client”). The example shows how to build BLE SPP (Serial Port Profile, UART-BLE passthrough mode) with AT commands. Notice:

The ESP32 Server needs to download a “service bin” into Flash to provide BLE services.
- To learn how to generate a “service bin”, please refer to esp-at/tools/readme.md.
- The download address of the “service bin” is the address of “ble_data” in esp-at/partitions_at.csv.

BLE initialization:

ESP32 Server:

 AT+BLEINIT=2                              // server role

 OK

 AT+BLEGATTSSRVCRE                         // Create services

 OK

 AT+BLEGATTSSRVSTART                       // Start services

 OK

ESP32 Client:

 AT+BLEINIT=1                              // client role

 OK

Establish BLE connection:

ESP32 Server:
(1) Query the BLE address. For example, its address is “24:0a:c4:03:f4:d6”.

 Command:
 AT+BLEADDR?                              // get server's BLE address

 Response:
 +BLEADDR:24:0a:c4:03:f4:d6

 OK

(2) Optional Configuration, configure advertisement data. Without the configuration, the payload of the broadcasting packet will be empty.

 Command:
 AT+BLEADVDATA="0201060A09457370726573736966030302A0"

 /*  The adv data is 
  *  02 01 06  //<length>,<type>,<data>
  *  0A 09 457370726573736966 //<length>,<type>,<data> 
  *  03 03 02A0  //<length>,<type>,<data> 
  */

 Response:
 OK

(3) Start advertising.

 Command:
 AT+BLEADVSTART

 Response:
 OK

ESP32 Client:
(1) Start scanning.

 Command:
 AT+BLESCAN=1,3

 Response:
 +BLESCAN:<BLE address>,<rssi>,<adv_data>,<scan_rsp_data>

 OK

(2) Establish the BLE connection, when the server is scanned successfully.

 AT+BLECONN=0,"24:0a:c4:03:f4:d6"

 Response:
 OK
 +BLECONN:0,"24:0a:c4:03:f4:d6"

Notes:

If the BLE connection is established successfully, it will prompt +BLECONN:<conn_index>,<remote_BLE_address>
If the BLE connection is broken, it will prompt +BLEDISCONN:<conn_index>,<remote_BLE_address>

Discover services.

ESP32 Server:
(1) Discover local services.

 AT+BLEGATTSSRV?     

 Response:
 +BLEGATTSSRV:1,1,0xA002,1

 OK

(2) Discover characteristics.

 AT+BLEGATTSCHAR?          

 Response:
 +BLEGATTSCHAR:"char",1,1,0xC300
 +BLEGATTSCHAR:"desc",1,1,1
 +BLEGATTSCHAR:"char",1,2,0xC301
 +BLEGATTSCHAR:"desc",1,2,1
 +BLEGATTSCHAR:"char",1,3,0xC302
 +BLEGATTSCHAR:"desc",1,3,1

 OK

ESP32 Client:
(1) Discover services.

 AT+BLEGATTCPRIMSRV=0   

 Response:
 +BLEGATTCPRIMSRV:0,1,0x1801,1
 +BLEGATTCPRIMSRV:0,2,0x1800,1
 +BLEGATTCPRIMSRV:0,3,0xA002,1

 OK

Notice:

When discovering services, the ESP32 Client will get two more default services (UUID:0x1800 and 0x1801) than what the ESP32 Server will get.
So, for the same service, the <srv_index> received by the ESP32 Client equals the <srv_index> received by ESP32 Server + 2.
For example, the <srv_index> of the above-mentioned service, 0xA002, is 3 when the ESP32 Client is in the process of discovering services. But if the ESP32 Server tries to discover it with command AT+BLEGATTSSRV?, the <srv_index> will be 1.

(2) Discover characteristics.

 AT+BLEGATTCCHAR=0,3

 Response:
 +BLEGATTCCHAR:"char",0,3,1,0xC300,2
 +BLEGATTCCHAR:"desc",0,3,1,1,0x2901
 +BLEGATTCCHAR:"char",0,3,2,0xC301,2
 +BLEGATTCCHAR:"desc",0,3,2,1,0x2901
 +BLEGATTCCHAR:"char",0,3,3,0xC302,8
 +BLEGATTCCHAR:"desc",0,3,3,1,0x2901
 +BLEGATTCCHAR:"char",0,3,4,0xC303,4
 +BLEGATTCCHAR:"desc",0,3,4,1,0x2901
 +BLEGATTCCHAR:"char",0,3,5,0xC304,8
 +BLEGATTCCHAR:"char",0,3,6,0xC305,16
 +BLEGATTCCHAR:"desc",0,3,6,1,0x2902
 +BLEGATTCCHAR:"char",0,3,7,0xC306,32
 +BLEGATTCCHAR:"desc",0,3,7,1,0x2902

 OK  

Configure BLE SPP:

ESP32 Client:
(1) Set a characteristic that enables writing permission to TX channel for sending data. Set another characteristic that supports notification or indication to RX channel for receiving data.
```
 AT+BLESPPCFG=1,3,5,3,7

 Response:
 OK
```
(2) Enable BLE SPP:
```
 AT+BLESPP

 Response:
 OK
 >	                 // waiting for serial data
```

Note: After ESP32 Client enabling BLE SPP, data received from serial port will be transmitted to the BLE server directly.

ESP32 Server:  
(1) Set a characteristic that supports notification or indication to TX channel for sending data. Set another characteristic that enables writing permission to RX channel for receiving data.

    AT+BLESPPCFG=1,1,7,1,5
    
    Response:
    OK
(2) Enable BLE SPP:

    AT+BLESPP
    
    Response:
    OK
    >	                 // waiting for serial data

Notes:

After ESP32 Server enables BLE SPP, the data received from serial port will be transmitted to the BLE client directly.
If the ESP32 Client does not enable BLE SPP first, or uses other device as BLE client, then the BLE client needs to listen to the notification or indication first. For example, if the ESP32 Client does not enable BLE SPP first, then it should enable listening with command AT+BLEGATTCWR=0,3,7,1,1 first for the ESP32 Server to transmit successfully.
For the same service, the <srv_index> on the ESP32 Client side equals the <srv_index> on the ESP32 Server side plus 2.

Example 1: MQTT over TCP (with a Local MQTT Broker)¶

Create a local MQTT broker. For example, the MQTT broker’s IP address is “192.168.31.113”, port 1883. Then the example of communicating with the MQTT broker will be as the following steps.

AT+MQTTUSERCFG=0,1,"ESP32","espressif","1234567890",0,0,""
AT+MQTTCONN=0,"192.168.31.113",1883,0
AT+MQTTSUB=0,"topic",1
AT+MQTTPUB=0,"topic","test",1,0
AT+MQTTCLEAN=0

Example 2: MQTT over TLS (with a Local MQTT Broker)¶

Create a local MQTT broker. For example, the MQTT broker’s IP address is “192.168.31.113”, port 1883. Then the example of communicating with the MQTT broker will be as the following steps.

AT+CIPSNTPCFG=1,8,"ntp1.aliyun.com"
AT+CIPSNTPTIME?
AT+MQTTUSERCFG=0,3,"ESP32","espressif","1234567890",0,0,""
AT+MQTTCONNCFG=0,0,0,"lwtt","lwtm",0,0
AT+MQTTCONN=0,"192.168.31.113",1883,0
AT+MQTTSUB=0,"topic",1
AT+MQTTPUB=0,"topic","test",1,0
AT+MQTTCLEAN=0

Example 3: MQTT over WSS ¶

This is an example of communicating with MQTT broker: iot.eclipse.org, of which port is 443.

AT+CIPSNTPCFG=1,8,"ntp1.aliyun.com"
AT+CIPSNTPTIME?
AT+MQTTUSERCFG=0,7,"ESP32","espressif","1234567890",0,0,"wss"
AT+MQTTCONN=0,"iot.eclipse.org",443,0
AT+MQTTSUB=0,"topic",1
AT+MQTTPUB=0,"topic","test",1,0
AT+MQTTCLEAN=0

[ESP32 Only] Ethernet AT Examples¶

Note

Before you run any Ethernet AT commands, please make sure you have followed the Prerequisite.

Establish a TCP Connection on Ethernet Network

Establish a TCP Connection on Ethernet Network¶

Enable multiple connections.
- Command
```
AT+CIPMUX=1
```
- Response
```
OK
```
Create a TCP server.
- Command
```
AT+CIPSERVER=1,8081
```
- Response
```
OK
```

Obtain the IP address of the server.

Command
```
AT+CIPETH?
```

Response

+CIPETH:ip:192.168.105.24
+CIPETH:gateway:192.168.105.1
+CIPETH:netmask:255.255.255.0
OK

Use a network tool on PC to create a TCP client and connect to the TCP server that ESP created. (IP: 192.168.105.24, Port: 8081).
Send data in Normal Transmission Mode.
- Command
```
AT+CIPSEND=0,4    // send 4 bytes to connection ID 0
```
- Response
```
OK
>
```
- Enter the data.
- Response
```
SEND OK
```
Note: If the length of the data you entered is more than the value of <length> (n) set by AT+CIPSEND, the system will prompt busy, and send the first n bytes. After sending the first n bytes, the system will reply SEND OK.
Receive data in Normal Transmission Mode.

When the ESP server receives data, AT will prompt:
```
+IPD,n:xxxxxxxxxx    // received n bytes, data=xxxxxxxxxxx
```
Close TCP Connection.
- Command
```
AT+CIPCLOSE=0
```
- Response
```
OK
```
Delete the TCP server.
- Command
```
AT+CIPSERVER=0
```
- Response
```
OK
```

Web Server AT Example¶

[中文]

This document mainly introduces the use of AT web server, mainly involving the following applications:

Wi-Fi Provisioning Using a Browser
OTA Firmware Upgrade Using a Browser
Wi-Fi Provisioning Using a WeChat Applet
OTA Firmware Upgrade Using a WeChat Applet
[ESP32][ESP32-S Series][ESP32-C Series] Using Capture Portal

Note

The default firmware does not support web server AT commands, please refer to Web server AT Commands to enable the web server.

Wi-Fi Provisioning Using a Browser ¶

Introduction¶

With the web server, mobile phone or PC is able to control ESP device‘s Wi-Fi provisioning service. You can use a mobile phone or computer to connect to the SoftAP of the ESP device, open the web pages via browser, start provisioning service, and then the ESP device can connect to the target router as you set.

Introduction to Operation Steps¶

The whole process can be divided into the following three steps:

Use STA Device to Connect to ESP Device
Use the Browser to Send Wi-Fi Connection Information
Get the Result of Wi-Fi Connection

Use STA Device to Connect to ESP Device ¶

Firstly, ESP device needs to be configured to softAP + STA mode, and creates a web server to wait for Wi-Fi provisioning messages. In this case, a mobile phone or a PC can connect to the ESP softAP as a station. The corresponding AT commands are as follows:

Clear the previous Wi-Fi provisioning information.
- Command
```
AT+RESTORE
```
Set the Wi-Fi mode to Station+SoftAP.
- Command
```
AT+CWMODE=3
```
Set the configuration of an ESP SoftAP.（For example, set the default connection ssid to “pos_softap”, Wi-Fi without password.）
- Command
```
AT+CWSAP="pos_softap","",11,0,3
```
Enable multiple connections.
- Command
```
AT+CIPMUX=1
```
Create a web server, port: 80, connection timeout: 25 s (default maximum is 60 s).
- Command
```
AT+WEBSERVER=1,80,25
```

After starting the web sever according to the above commands, you can turn on the Wi-Fi connection function on your STA device, and connect it to the softAP of the ESP device:

connects_to_the_ESP_AP — The browser connects to the ESP AP¶

Use the Browser to Send Wi-Fi Connection Information ¶

After your STA device connected to the ESP softAP, it can send Wi-Fi connection information to ESP in an HTTP request. Please note that if your target AP is the hotspot of the device which opens the web pages, you may not receive the Wi-Fi connection result. You can enter the default IP address of the web server in the browser (the default IP is 192.168.4.1, or you can query the current SoftAP IP address by command AT+CIPAP?), open the Wi-Fi provisioning interface, and enter the ssid and password of the router to be connected, click “Connect” to let ESP device start connecting to the router:

opens_the_Wi-Fi_configuration_interface — The browser opens the Wi-Fi provisioning interface¶

Or you can click the drop-down box of SSID to list all APs nearby, select the target AP and enter the password, and then click “Connect” to let the ESP device start connecting to the router:

Schematic_diagram_of_browser_obtaining_Wi-Fi_AP_list — Schematic diagram of browser obtaining Wi-Fi AP list¶

Get the Result of Wi-Fi Connection ¶

After the Wi-Fi connection is established successfully, the web page will be displayed as follows:

Browser_Wi-Fi_configuration_is_successful — Wi-Fi connection is established successfully¶

Note 1: After the Wi-Fi connection is established successfully, the webpage will be closed automatically. If you want to continue to access the webpage, please re-enter the IP address of the ESP device and reopen the webpage.

At the same time, the following messages will be returned from the ESP-AT command port:

+WEBSERVERRSP:1      // meaning that ESP device has received Wi-Fi connection information
WIFI CONNECTED       // meaning that ESP device is connecting
WIFI GOT IP          // meaning that ESP device connect successfully to the destination rounter
+WEBSERVERRSP:2      // meaning that STA device has received Wi-Fi connection result, and web resources can be released

If the ESP device fails to connect to the router, the web page will display:

ESP_device_connects_fail — ESP device fails to connect to the router¶

At the same time, the following messages will be returned from the ESP-AT command port:

+WEBSERVERRSP:1      // meaning that ESP device has received Wi-Fi connection information, but failed to connect to the rounter.

Troubleshooting¶

Note 1: The network configuration page received a prompt “Connection failed”. Please check whether the Wi-Fi AP of the ESP module is correctly turned on, and the relevant configuration of the AP, and confirm that the correct AT command has been entered to successfully enable the web server.

OTA Firmware Upgrade Using a Browser ¶

Introduction¶

After the browser opens the web page of the web server, you can choose to enter the OTA upgrade page to upgrade the firmware of the ESP device through the web page.

Introduction to Operation Steps¶

Open the OTA Configuration Page
Select and Send the New Firmware
Get the Result of OTA

Open the OTA Configuration Page ¶

As shown in the figure, click on the “OTA” option in the lower right corner of the web page, and after opening the OTA configuration page, you can view the current firmware version and AT Core version:

Note 1: The configuration interface can only be opened when the STA device is connected to the AP of the ESP device, or the STA device accessing the OTA configuration page is connected to the ESP device in the same subnet.

Note 2: The “current app version” displayed on the webpage is the version number of the application. You can change the version number through ./build.py menuconfig –> Component config –> AT –> AT firmware version (see Build Your Own ESP-AT Project). In this case, you can manage your application firmware version.

Select and Send the New Firmware ¶

As shown in the figure, click the “Browse” button on the page and select the new firmware to be sent:

Select_the_new_version_of_firmware_to_be_sent — Select the new version of firmware to be sent¶

Note 1: Before sending the new firmware, the system will check the selected firmware. The suffix of the firmware name must be .bin, and its size should not exceed 2M.

Get the Result of OTA ¶

As shown in the figure, if the ESP device OTA successfully, it will prompt “OTA Succeeded”:

The_new_firmware_was_sent_successfully — The new firmware was sent successfully¶

At the same time, the following messages will be returned from the ESP-AT command port:

+WEBSERVERRSP:3      // meaning that ESP device begin to receive ota data
+WEBSERVERRSP:4      // meaning that ESP device has received all firmware data，and you can choose to restart the ESP device to apply the new firmware

If the received firmware data verification fails, the following message will be received on the serial port:

+WEBSERVERRSP:3      // meaning that ESP device begin to receive ota data
+WEBSERVERRSP:5      // meaning that the received OTA data verification failed. You can choose to reopen the OTA configuration interface and follow the above steps to restart the firmware upgrade

Wi-Fi Provisioning Using a WeChat Applet ¶

Introduction¶

The WeChat applet can automatically connect to the WiFi AP of the ESP device, and then send the ssid and password required by the ESP device to connect to the network.

Introduction to Operation Steps¶

The whole process can be divided into the following four steps:

Configure ESP Device Parameters
Load WeChat Applet
Target AP Selection
Use the WeChat Applet to Send Wi-Fi Connection Information

Configure ESP Device Parameters ¶

Firstly, ESP device needs to be configured to softAP + STA mode, and creates a web server to wait for Wi-Fi provisioning messages. In this case, a mobile phone or a PC can connect to the ESP softAP as a station. The corresponding AT commands are as follows:

Clear the previous Wi-Fi provisioning information.
- Command
```
AT+RESTORE
```
Set the Wi-Fi mode to Station+SoftAP.
- Command
```
AT+CWMODE=3
```
Set the configuration of an ESP SoftAP.（For example, set the default connection ssid to “pos_softap” , and password to “espressif”.）
- Command
```
AT+CWSAP="pos_softap","espressif",11,3,3
```

Note

By default, the WeChat applet initiates a connection to the SoftAP whose ssid is pos_softap and password is espressif. Please make sure to set the parameters of the ESP device according to the above configuration.

Enable multiple connections.
- Command
```
AT+CIPMUX=1
```
Create a web server, port: 80, connection timeout: 40 s (default maximum is 60 s).
- Command
```
AT+WEBSERVER=1,80,40
```

Load WeChat Applet ¶

Open the mobile phone WeChat, scan the following QR code:

Get_the_QR_code_of_the_applet — Get the QR code of the applet¶

Open the WeChat applet and enter the Wi-Fi provisioning interface:

Wi-Fi_configuration_interface — Wi-Fi provisioning interface¶

Target AP Selection ¶

After loading the WeChat applet, there are two situations according to different target AP:

Situation 1. If your target AP is the hotspot of the mobile phone which running the WeChat applet, please select the “Local phone hotspot” option box on the WeChat applet page.

Situation 2. If your target AP is just another AP, not as the special situation one as above, then please do not select the “Local phone hotspot” option box.

Use the WeChat Applet to Send Wi-Fi Connection Information ¶

The target AP to be accessed is not the hotspot provided by the mobile phone which loading the WeChat applet.¶

Here, take connecting to a router as an example, the process of Wi-Fi Connection configuration is introduced:

1.Turn on the mobile Wi-Fi and connect to the router:

connect_to_the_rounter — connect to the rounter¶

2.Open the WeChat applet, you can see that the applet page has automatically displayed the ssid of the current router as “FAST_FWR310_02”.

get_rounter_info — The applet obtains the information of the router to be connected¶

Note: If the ssid of the connected router is not displayed on the current page, please click “Re-enter applet” in the following figure to refresh the current page:

Re-enter_the_applet — Re-enter the applet¶

3.After entering the password of the router, click “Connect”.

wechat_rounter_connecting — The applet starts the ESP device to connect to the router¶

4.After the Wi-Fi connection is established successfully, the web page will be displayed as follows:

wechat_rounter_connect_success — The applet Wi-Fi provisioning is successful¶

At the same time, the following messages will be returned from the ESP-AT command port:

+WEBSERVERRSP:1      // meaning that ESP device has received Wi-Fi connection information
WIFI CONNECTED       // meaning that ESP device is connecting
WIFI GOT IP          // meaning that ESP device connect successfully to the destination rounter
+WEBSERVERRSP:2      // meaning that STA device has received Wi-Fi connection result, and web resources can be released

5.If the ESP device fails to connect to the router, the page will display:

wechat_rounter_connect_fail — The applet Wi-Fi provisioning is failed¶

At the same time, the following messages will be returned from the ESP-AT command port:

+WEBSERVERRSP:1      // meaning that ESP device has received Wi-Fi connection information, but failed to connect to the rounter.

The target AP to be accessed is the hotspot provided by the mobile phone which loading the WeChat applet.¶

If the target AP to be accessed is the hotspot provided by the mobile phone which loading the WeChat applet, it is not necessary to enter the ssid, but only needs to enter the password of the AP, and turn on the mobile AP in time according to the prompts.

1.Select the “Local phone hotspot” option box on the WeChat applet page, enter the password of the local hotspot, and click “Connect”.

wechat_enter_local_password — Enter the password of the AP¶

2.After receiving the prompt “Connecting to the mobile phone hotspot”, please check that the local mobile phone hotspot is turned on. At this time, the ESP device will automatically scan the surrounding hotspots and initiate a connection.

wechat_start_connect — Start to connect to the AP¶

3.The display of the WiFi connection results on the applet page and the data output from the serial port are the same as the above-mentioned “The target AP to be accessed is not the hotspot provided by the mobile phone which loading the WeChat applet.”, please refer to the above.

Troubleshooting¶

Note 1: The Wi-Fi provisioning page received a prompt “Data transmission failed”. Please check whether the Wi-Fi AP of the ESP device is correctly turned on, and the relevant configuration of the AP, and confirm that the correct AT command has been entered to successfully enable the web server.

Note 2: The Wi-Fi provisioning page receives a prompt “Failed to connect to the AP”. Please check whether the Wi-Fi connection function of the mobile phone is turned on, check whether the Wi-Fi AP of the ESP device is correctly turned on, and whether the ssid and password of the AP are configured according to the above steps.

Note 3: The Wi-Fi provisioning page receives a prompt “The Wi-Fi provisioning saved by the system expired”. Please manually connect the ESP device AP with a mobile phone, and confirm that the ssid and password of the ESP module have been configured according to the above steps.

OTA Firmware Upgrade Using a WeChat Applet ¶

The WeChat applet support online firmware upgrade , please refer to the above-described Configure ESP Device Parameters specific steps performed ESP device configuration (if the configuration has been completed, do not repeat configuration). Once configured, the device performs OTA firmware upgrade processes is similar as OTA Firmware Upgrade Using a Browser .

[ESP32][ESP32-S Series][ESP32-C Series] Using Capture Portal ¶

Introduction¶

Captive Portal is commonly used to present a specified page to newly connected devices of a Wi-Fi or wired network. For more information about Captive Portal, please refer to Captive Portal Wiki .

Note

The default firmware does not support web server Captive Portal, you may enable it by ./build.py menuconfig > Component config > AT > AT WEB Server command support > AT WEB captive portal support and build the project (see Build Your Own ESP-AT Project). In addition, enabling this feature may cause page skipping when using wechat applet for Wi-Fi provisioning or OTA firmware upgrade. It is recommended that this feature be enabled only when accessing at web using browser.

Introduction to Operation Steps¶

After Enable Captive Portal support, please refer to Use STA Device to Connect to ESP Device to complete the configuration of the ESP device, and then connect to the AP of the ESP device:

auth_pages — Connect to the AP with Captive Portal enabled¶

As shown in the figure above, after the Station device is connected to the AP of the ESP device with the Captive Portal function enabled, it will prompt “requires login/authentication”, and then the browser will automatically open and jump to the main interface of AT Web. If it cannot be redirected automatically, please follow the instructions of the Station device, click “Authentication” or click the name of the “pos_softap” hotspot in the figure above to manually trigger the Captive Portal to automatically open the browser and enter the main interface of AT Web.

Troubleshooting¶

Note 1: Both Station device and AP device support the Captive Portal function to ensure the normal use of this function. Therefore, if the device is connected to the AP of the ESP device, but it does not prompt “Login/Authentication”, it may be that the Station device does not support this function. In this case, please refer to the specific steps of Use the Browser to Send Wi-Fi Connection Information above to open the main interface of AT Web.

How to compile and develop your own AT project¶

[中文]

Build Your Own ESP-AT Project¶

This document details how to build your own ESP-AT project and flash the generated binary files into your ESP devices, including ESP32, ESP32-S2, ESP32-C3, and ESP8266. It comes in handy when the default AT Binary Lists cannot meet your needs, for example, to customize the AT port pins, Bluetooth service, partitions, and so on.

The structure of this document is as follows:

Overview: Overview of the steps to build an ESP-AT project.
ESP32, ESP32-S2 and ESP32-C3 Series: Details steps to build a project for ESP32, ESP32-S2, and ESP32-C3 series.
ESP8266 Series: Details steps to build a project for ESP8266.

Overview¶

Before compiling an ESP-AT project, you need first get started with ESP-IDF and set up the environment for ESP-IDF, because ESP-AT is based on ESP-IDF.

After the environment is ready, install the tools and ESP-AT SDK. Then, connect your ESP device to PC. Use ./build.py menuconfig to set up some configuration for the project. Build the project and flash the generated bin files onto your ESP device.

Note

Please pay attention to possible conflicts of pins. If choosing AT through HSPI, you can get the information of the HSPI pin by ./build.py menuconfig –> Component config –> AT –> AT hspi settings.

ESP32, ESP32-S2 and ESP32-C3 Series¶

This section describes how to compile an ESP-AT project for ESP32, ESP32-S2 and ESP32-C3 series.

Get Started with ESP-IDF¶

Get started with ESP-IDF before compiling an ESP-AT project, because ESP-AT is developed based on ESP-IDF, and the supported version varies from series to series:

ESP-IDF Versions for Different Series¶
Project	IDF Version	IDF Documentation Version
ESP32 ESP-AT	release/v4.2	ESP-IDF Get Started Guide v4.2
ESP32-S2 ESP-AT	release/v4.2	ESP-IDF Get Started Guide v4.2
ESP32-C3 ESP-AT	release/v4.3	ESP-IDF Get Started Guide v4.3

First, set up the development environment for ESP-IDF according to Step 1 to 4 of ESP-IDF Get Started Guide (click the corresponding link in the table above to navigate to the documentation).

Then, start a simple project of hello_world according to Step 5 to 10 of ESP-IDF Get Started Guide to make sure your environment works and familiarize yourself with the process of starting a new project based on ESP-IDF. It is not a must, but you are strongly recommended to do so.

After finishing all the ten steps (if not, at least the first four steps), you can move onto the following steps that are ESP-AT specific.

Note

Please do not set IDF_PATH during the process, otherwise, you would encounter some unexpected issues when compiling ESP-AT projects later.

Get ESP-AT¶

To compile an ESP-AT project, you need the software libraries provided by Espressif in the ESP-AT repository.

To get ESP-AT, navigate to your installation directory and clone the repository with git clone, following instructions below specific to your operating system.

Linux or macOS

cd ~/esp
git clone --recursive https://github.com/espressif/esp-at.git

Windows

cd %userprofile%\esp
git clone --recursive https://github.com/espressif/esp-at.git

If you are located in China or have difficulties to access GitHub, you can also use git clone https://gitee.com/EspressifSystems/esp-at.git to get ESP-AT, which may be faster.

ESP-AT will be downloaded into ~/esp/esp-at on Linux or macOS, or %userprofile%\esp\esp-at on Windows.

Note

This guide uses the directory ~/esp on Linux or macOS, or %userprofile%\esp on Windows as an installation folder for ESP-AT. You can use any directory, but you will need to adjust paths for the commands respectively. Keep in mind that ESP-AT does not support spaces in paths.

Connect Your Device¶

Connect your device to the PC with a USB cable to download firmware and log output. See Hardware Connection for more information. Note that you do not need to set up the “AT command/response” connection if you do not send AT commands and receive AT responses during the compiling process. You can change default port pins referring to How to Set AT Port Pins.

Configure¶

In this step, you will clone the esp-idf folder into the esp-at folder, set up the development environment in the newly cloned folder, and configure your project.

Navigate to ~/esp/esp-at directory.
Run the project configuration utility menuconfig to configure.

./build.py menuconfig

Select the following configuration options for your ESP device if it is your first time.

Select the Platform name for your ESP device. For example, select PLATFORM_ESP32 for ESP32 series of products, PLATFORM_ESP32S2 for ESP32-S2 series of products. Platform name is defined in factory_param_data.csv .

Select the Module name for your ESP device. For example, select WROOM-32 for the ESP32-WROOM-32D module. Module name is defined in factory_param_data.csv .

Enable or disable silence mode. If enabled, it will remove some logs and reduce the firmware size. Generally, it should be disabled.

The above three option items will not appear if the file build/module_info.json exists. So please delete it if you want to reconfigure the module information.

Now, the esp-idf folder is created in esp-at folder. This esp-idf is different from that in Step Get Started with ESP-IDF.

If the terminal prompt an error message like the following, please proceed with the next step to set up the develop environment in the esp-at/esp-idf.
The following Python requirements are not satisfied:
...
Please follow the instructions found in the "Set up the tools" section of ESP-IDF Get Started Guide.
If you have compiled an ESP-AT project for an ESP series before and want to switch to another series, you must run rm -rf esp-idf to remove the old esp/idf and then proceed with the next step.

If your esp-idf is upgraded, you are recommended to proceed with the next step.

Set up the development environment in the esp-at/esp-idf.

Set up the tools in the folder if it is the first time you compile the ESP-AT project. See Step 3 of ESP-IDF Get Started Guide.

Set up environment variables in the folder every time you compile an ESP-AT project. See Step 4 of ESP-IDF Get Started Guide.
Install pyyaml and xlrd packages with pip in the folder if you have not done it.
python -m pip install pyyaml xlrd

If the previous steps have been done correctly, the following menu appears after you run ./build.py menuconfig:

You are using this menu to set up project-specific configuration, e.g. changing AT port pins, enabling Classic Bluetooth function, etc. If you made no changes, it will run with the default configuration.

Build the Project¶

Build the project by running:

./build.py build

If Bluetooth feature is enabled, the firmware size will be much larger. Please make sure it does not exceed the ota partition size.
After compiled, the combined factory bin will be created in build/factory. See How to understand the differences of each type of module for more information.

Flash onto the Device¶

Flash the binaries that you just built onto your ESP32 board by running:

./build.py -p (PORT) flash

Note that you may need to replace PORT with your ESP device’s serial port name.
Or you can follow the printed instructions to flash the bin files into flash. Note that you may also need to replace the PORT.
If the ESP-AT bin fails to boot and prints “ota data partition invalid”, you should run ./build.py erase_flash to erase the entire flash, and then re-flash the AT firmware.

ESP8266 Series¶

This section describes how to compile an ESP-AT project for ESP8266 series.

Get Started with ESP-IDF¶

Get started with ESP-IDF before compiling an ESP-AT project, because ESP-AT is developed based on ESP-IDF:

First, set up the development environment according to ESP8266 RTOS SDK Get Started Guide v3.4.

Then, start a simple project of hello_world according to the Guide to make sure your environment works and familiarize yourself with the process of starting a new project based on ESP-IDF. It is not a must, but you are strongly recommended to do so.

After setting up the development environment and starting a simple project, you can move onto the following steps that are ESP-AT specific.

Note

Please do not set IDF_PATH during the process, otherwise, you would encounter some unexpected issues when compiling ESP-AT projects later.

Get ESP-AT¶

To compile an ESP-AT project, you need the software libraries provided by Espressif in the ESP-AT repository.

To get ESP-AT, navigate to your installation directory and clone the repository with git clone, following instructions below specific to your operating system.

Linux or macOS

cd ~/esp
git clone --recursive https://github.com/espressif/esp-at.git

Windows

cd %userprofile%\esp
git clone --recursive https://github.com/espressif/esp-at.git

If you are located in China or have difficulties to access GitHub, you can also use git clone https://gitee.com/EspressifSystems/esp-at.git to get ESP-AT, which may be faster.

ESP-AT will be downloaded into ~/esp/esp-at on Linux or macOS, or %userprofile%\esp\esp-at on Windows.

Note

This guide uses the directory ~/esp on Linux and macOS or %userprofile%\esp on Windows as an installation folder for ESP-AT. You can use any directory, but you will need to adjust paths for the commands respectively. Keep in mind that ESP-AT does not support spaces in paths.

Checkout to ESP8266 Branch¶

git checkout release/v2.2.0.0_esp8266

Connect Your Device¶

Connect your device to the PC with a USB cable to download firmware and log output. See Hardware Connection for more information. Note that you do not need to set up the “AT command/response” connection if you do not send AT commands and receive AT responses during the compiling process. You can change default port pins referring to How to Set AT Port Pins.

Configure¶

In this step, you will clone the esp-idf folder into the esp-at folder, set up the development environment in the newly cloned folder, and configure your project.

Navigate back to your ~/esp/esp-at directory.
Run the project configuration utility menuconfig to configure.

./build.py menuconfig

Select the following configuration options for your ESP device if it is the first time you build the ESP-AT project.

Select the Platform name for your ESP device, i.e., select PLATFORM_ESP8266 for your ESP8266 device. Platform name is defined in factory_param_data.csv .

Select the Module name for your ESP device. For example, select WROOM-02 for the ESP-WROOM-02D module. Module name is defined in factory_param_data.csv .

Enable or disable silence mode. If enabled, it will remove some logs and reduce the firmware size. Generally, it should be disabled.

The above three option items will not appear if the file build/module_info.json exists. So please delete it if you want to reconfigure the module information.

Now, the esp-idf folder is created in esp-at folder. This esp-idf is different from that in Step Get Started with ESP-IDF.

If the terminal prompt an error message like the following, please proceed with the next step to set up the develop environment in the esp-at/esp-idf.
The following Python requirements are not satisfied:
...
Please follow the instructions found in the "Set up the tools" section of ESP-IDF Get Started Guide.
If you have compiled an ESP-AT project for an ESP series before and want to switch to another series, you must run rm -rf esp-idf to remove the old esp/idf and then proceed with the next step.

If your esp-idf is upgraded, you are recommended to proceed with the next step.

Set up the development environment in the esp-at/esp-idf.

Set up the tools in the folder if it is the first time you compile an ESP-AT project. See ESP8266 RTOS SDK Get Started Guide v3.4 for more information.

Set up environment variables in the folder every time you compile an ESP-AT project. See ESP8266 RTOS SDK Get Started Guide v3.4 for more information.
Install pyyaml and xlrd packages with pip in the folder if you have not done it.
python -m pip install pyyaml xlrd

If the previous steps have been done correctly, the following menu appears after you run ./build.py menuconfig:

You are using this menu to set up project-specific configuration, e.g. changing AT port pins, enabling Classic Bluetooth function, etc. If you made no changes, it will run with the default configuration.

Build the Project¶

Build the project by running:

./build.py build

After compiled, the combined factory bin will be created in build/factory. By default, the factory bin is 2 MB flash size, DIO flash mode and 80 MHz flash speed. See How to understand the differences of each type of module for more information.

Flash onto the Device¶

Flash the binaries that you just built onto your ESP8266 board by running:

./build.py -p (PORT) flash

Note that you may need to replace PORT with your ESP device’s serial port name.
Or you can follow the printed instructions to flash the bin files into flash. Note that you may also need to replace the PORT.
If the ESP-AT bin fails to boot and prints “ota data partition invalid”, you should run ./build.py erase_flash to erase the entire flash, and then re-flash the AT firmware.

How to Set AT Port Pins¶

This document introduces how to modify AT port pins in the firmware for ESP32, ESP32-S2, ESP32-C3, and ESP8266 series of products. By default, ESP-AT uses two UART interfaces as AT ports: one is to output logs (named as log port below) and the other to send AT commands and receive responses (named as command port below).

To modify the AT port pins of your ESP device, you should:

clone the esp-at project;
modify the pins either in the menuconfig utility or the factory_param_data.csv table;
compile the project to generate the new bin in build/customized_partitions/factory_param.bin;
flash the new bin to your device.

This document focuses on modifying the pins. Click the links above for details of other steps. Below is the document structure:

ESP32 Series
ESP32-S2 Series
ESP32-C3 Series
ESP8266 Series

Note

To use other interfaces as the AT command port, please refer to AT through SDIO , AT through SPI , or AT through socket for more details.

ESP32 Series¶

The log port and command port pins of ESP32 AT firmware can be user-defined to other pins. Refer to ESP32 Technical Reference Manual for the pins you can use.

Modify Log Port Pins¶

By default, the ESP32 AT firmware provided by Espressif uses the following UART0 pins to output log:

TX: GPIO1
RX: GPIO3

When compiling your esp-at project, you can modify them to other pins with the menuconfig utitlity:

./build.py menuconfig –> Component config –> Common ESP-related –> UART for console output
./build.py menuconfig –> Component config –> Common ESP-related –> UART TX on GPIO#
./build.py menuconfig –> Component config –> Common ESP-related –> UART RX on GPIO#

Modify Command Port Pins¶

By default, UART1 is used to send AT commands and receive AT responses, and its pins are defined in Column uart_port, uart_tx_pin, uart_rx_pin, uart_cts_pin, and uart_rts_pin of the factory_param_data.csv .

You can change them directly in your factory_param_data.csv table:

Open your local factory_param_data.csv file.
Locate the row of your module.
Set uart_port as needed.
Set uart_tx_pin and uart_rx_pin as needed.
Set uart_cts_pin and uart_rts_pin to be -1 if you do not use the hardware flow control function.
Save the table.

ESP32-S2 Series¶

The log port and command port pins of ESP32-S2 AT firmware can be user-defined to other pins. Refer to ESP32-S2 Technical Reference Manual for the pins you can use.

Modify Log Port Pins¶

By default, the ESP32-S2 AT firmware provided by Espressif uses the following UART0 pins to output log:

TX: GPIO43
RX: GPIO44

When compiling your esp-at project, you can modify them to other pins with the menuconfig utitlity:

./build.py menuconfig –> Component config –> Common ESP-related –> UART for console output
./build.py menuconfig –> Component config –> Common ESP-related –> UART TX on GPIO#
./build.py menuconfig –> Component config –> Common ESP-related –> UART RX on GPIO#

Modify Command Port Pins¶

By default, UART1 is used to send AT commands and receive AT responses, and its pins are defined in Column uart_port, uart_tx_pin, uart_rx_pin, uart_cts_pin, and uart_rts_pin of the factory_param_data.csv .

You can change them directly in your factory_param_data.csv table:

Open your local factory_param_data.csv file.
Locate the row of your module.
Set uart_port as needed.
Set uart_tx_pin and uart_rx_pin as needed.
Set uart_cts_pin and uart_rts_pin to be -1 if you do not use the hardware flow control function.
Save the table.

ESP32-C3 Series¶

The log port and command port pins of ESP32-C3 AT firmware can be user-defined to other pins. ESP32-C3 Technical Reference Manual for the pins you can use.

Modify Log Port Pins¶

By default, the ESP32-C3 AT firmware provided by Espressif uses the following UART0 pins to output log:

TX: GPIO21
RX: GPIO20

When compiling your esp-at project, you can modify them to other pins with the menuconfig utitlity:

./build.py menuconfig –> Component config –> Common ESP-related –> UART for console output
./build.py menuconfig –> Component config –> Common ESP-related –> UART TX on GPIO#
./build.py menuconfig –> Component config –> Common ESP-related –> UART RX on GPIO#

Modify Command Port Pins¶

By default, UART1 is used to send AT commands and receive AT responses, and its pins are defined in Column uart_port, uart_tx_pin, uart_rx_pin, uart_cts_pin, and uart_rts_pin of the factory_param_data.csv .

You can change them directly in your factory_param_data.csv table:

Open your local factory_param_data.csv file.
Locate the row of your module.
Set uart_port as needed.
Set uart_tx_pin and uart_rx_pin as needed.
Set uart_cts_pin and uart_rts_pin to be -1 if you do not use the hardware flow control function.
Save the table.

ESP8266 Series¶

The log port and command port pins of the ESP8266 AT firmware can be user-defined to other pins, but with limited options. Please refer to ESP8266 Technical Reference Manual for more details.

Modify Log Port Pins¶

By default, the ESP8266 AT firmware provided by Espressif uses UART1 to log output. UART1 only supports GPIO2 as the TX pin, and the pin should not be modified.

However, you could modify the log port from UART1 to UART0 by:

./build.py menuconfig –> Component config –> Common ESP-related –> UART for console output

Modify Command Port Pins¶

By default, ESP8266 AT firmware uses UART0 to send AT commands and receive AT responses. The UART0 pins are defined in Column uart_port, uart_tx_pin, uart_rx_pin, uart_cts_pin, and uart_rts_pin of the factory_param_data.csv .

The UART pins can be changed, but there are only two choices: GPIO15 as TX pin, GPIO13 as RX or GPIO1 as TX, GPIO3 as RX. Below are the detailed steps:

Open your local factory_param_data.csv file.
Locate the row of your module.
Set uart_port as needed.
Set uart_tx_pin and uart_rx_pin to GPIO15 and GPIO13, or GPIO1 and GPIO3.
Set uart_cts_pin and uart_rts_pin to be -1 if you do not use the hardware flow control function.
Save the table.

For example, if you need to set GPIO1 (TX) and GPIO3 (RX) to be both the log port and command port of ESP-WROOM-02, do as follows:

Set log port to UART0: ./build.py menuconfig –> Component config –> ESP8266-specific –> UART for console output –> Default: UART0
Open your local factory_param_data.csv.
Find the row of WROOM-02, set uart_tx_pin to 1, uart_rx_pin to 3, uart_cts_pin to -1, uart_rts_pin to -1, and then save the table.

How to add user-defined AT commands¶

This document details how to add a user-defined AT command based on the esp-at project. It uses the AT+TEST command as an example to show the sample code for each step.

Customizing a basic and well-functioned command requires at least the two steps below:

Define AT Commands
Register AT Commands

This step checks how the newly defined command works out.

Give it a try

The remaining steps are for relatively complex AT commands and are optional depending on your needs.

Define Return Values
Access Command Parameters
Omit Command Parameters
Block Command Execution
Access Input Data from AT Command Port

The source code of AT command set is not open-source, and is provided in the form of library file . It is also the basis to parse user-defined AT commands.

Define AT Commands¶

Before defining any AT command, you should first decide on the name and type of the AT command you want to define.

Naming rules:

AT command should start with the + character.
Alphabetic characters (A~Z, a~z), numeric characters (0~9), and some other characters (!, %, -, ., /, :, _) are supported. See AT Command Types for more information.

Command types:

Each AT command can have up to four types: Test Command, Query Command, Set Command, and Execute Command. See AT Command Types for more information.

Then, define each type of command. Assuming that AT+TEST supports all the four types. Below is the sample code to define each type.

Test Command:

uint8_t at_test_cmd_test(uint8_t *cmd_name)
{
    uint8_t buffer[64] = {0};

    snprintf((char *)buffer, 64, "this cmd is test cmd: %s\r\n", cmd_name);

    esp_at_port_write_data(buffer, strlen((char *)buffer));

    return ESP_AT_RESULT_CODE_OK;
}

Query Command:

uint8_t at_query_cmd_test(uint8_t *cmd_name)
{
    uint8_t buffer[64] = {0};

    snprintf((char *)buffer, 64, "this cmd is query cmd: %s\r\n", cmd_name);

    esp_at_port_write_data(buffer, strlen((char *)buffer));

    return ESP_AT_RESULT_CODE_OK;
}

Set Command:

uint8_t at_setup_cmd_test(uint8_t para_num)
{
    int32_t para_int_1 = 0;
    uint8_t *para_str_2 = NULL;
    uint8_t num_index = 0;
    uint8_t buffer[64] = {0};

    if (esp_at_get_para_as_digit(num_index++, &para_int_1) != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    }

    if (esp_at_get_para_as_str(num_index++, &para_str_2) != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    }

    snprintf((char *)buffer, 64, "this cmd is setup cmd and cmd num is: %u\r\n", para_num);
    esp_at_port_write_data(buffer, strlen((char *)buffer));

    memset(buffer, 0, 64);
    snprintf((char *)buffer, 64, "first parameter is: %d\r\n", para_int_1);
    esp_at_port_write_data(buffer, strlen((char *)buffer));

    memset(buffer, 0, 64);
    snprintf((char *)buffer, 64, "second parameter is: %s\r\n", para_str_2);
    esp_at_port_write_data(buffer, strlen((char *)buffer));

    return ESP_AT_RESULT_CODE_OK;
}

Execute Command:

uint8_t at_exe_cmd_test(uint8_t *cmd_name)
{
    uint8_t buffer[64] = {0};

    snprintf((char *)buffer, 64, "this cmd is execute cmd: %s\r\n", cmd_name);

    esp_at_port_write_data(buffer, strlen((char *)buffer));

    return ESP_AT_RESULT_CODE_OK;
}

Finally, call esp_at_cmd_struct to define the name and type(s) that your AT command supports. The sample code below defined the name +TEST (omitting AT) and all the four types.

static esp_at_cmd_struct at_custom_cmd[] = {
    {"+TEST", at_test_cmd_test, at_query_cmd_test, at_setup_cmd_test, at_exe_cmd_test},
};

If you do not want to define a particular type, set it to NULL.

Register AT Commands¶

Call API esp_at_custom_cmd_array_regist() to register your AT command. Below is the sample code to register AT+TEST:

esp_at_custom_cmd_array_regist(at_custom_cmd, sizeof(at_custom_cmd) / sizeof(at_custom_cmd[0]));

Note

esp_at_custom_cmd_array_regist is recommended to be added to the at_custom_init() in app_main().

Give it a try¶

If you have finished the above two steps, the command should work after you build the esp-at project and flash the firmware to your device. Give it a try!

Below is how AT+TEST works out.

Test Command:

AT+TEST=?

Response:

AT+TEST=?
this cmd is test cmd: +TEST

OK

Query Command:

AT+TEST?

Response:

AT+TEST?
this cmd is query cmd: +TEST

OK

Set Command:

AT+TEST=1,"espressif"

Response:

AT+TEST=1,"espressif"
this cmd is setup cmd and cmd num is: 2
first parameter is: 1
second parameter is: espressif

OK

Execute Command:

AT+TEST

Response:

AT+TEST
this cmd is execute cmd: +TEST

OK

Define Return Values¶

ESP-AT has defined return values in esp_at_result_code_string_index. See AT Messages for more return values.

In addition to output return values through the return mode, you can also use API esp_at_response_result() to output the execution result of the command. ESP_AT_RESULT_CODE_SEND_OK and ESP_AT_RESULT_CODE_SEND_FAIL can be used with the API in code.

For example, when you send data to the server or MCU with the Execute Command of AT+TEST, you can use esp_at_response_result to output the sending result, and the return mode to output the command execution result. Below is the sample code:

uint8_t at_exe_cmd_test(uint8_t *cmd_name)
{
    uint8_t buffer[64] = {0};

    snprintf((char *)buffer, 64, "this cmd is execute cmd: %s\r\n", cmd_name);

    esp_at_port_write_data(buffer, strlen((char *)buffer));

    // user-defined operation of sending data to server or MCU
    send_data_to_server();

    // output SEND OK
    esp_at_response_result(ESP_AT_RESULT_CODE_SEND_OK);

    return ESP_AT_RESULT_CODE_OK;
}

How it works out:

AT+TEST
this cmd is execute cmd: +TEST

SEND OK

OK

Access Command Parameters¶

ESP-AT provides two APIs to access command parameters:

esp_at_get_para_as_digit() obtains digital parameters.
esp_at_get_para_as_str() obtains string parameters.

See Set Command for an example.

Omit Command Parameters¶

This section describes how to provide optional command parameters:

Omit the First or Middle Parameter
Omit the Last Parameter

Omit the First or Middle Parameter¶

Let’s say you want to make <param_2> and <param_3> of AT+TEST optional. <param_2> is a digital parameter, and <param_3> a string parameter.

AT+TEST=<param_1>[,<param_2>][,<param_3>],<param_4>

Below is the sample code to achieve it:

uint8_t at_setup_cmd_test(uint8_t para_num)
{
    int32_t para_int_1 = 0;
    int32_t para_int_2 = 0;
    uint8_t *para_str_3 = NULL;
    uint8_t *para_str_4 = NULL;
    uint8_t num_index = 0;
    uint8_t buffer[64] = {0};
    esp_at_para_parse_result_type parse_result = ESP_AT_PARA_PARSE_RESULT_OK;

    snprintf((char *)buffer, 64, "this cmd is setup cmd and cmd num is: %u\r\n", para_num);
    esp_at_port_write_data(buffer, strlen((char *)buffer));

    parse_result = esp_at_get_para_as_digit(num_index++, &para_int_1);
    if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    } else {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "first parameter is: %d\r\n", para_int_1);
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    parse_result = esp_at_get_para_as_digit(num_index++, &para_int_2);
    if (parse_result != ESP_AT_PARA_PARSE_RESULT_OMITTED) {
        if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
            return ESP_AT_RESULT_CODE_ERROR;
        } else {
            // sample code
            // user needs to customize the operation
            memset(buffer, 0, 64);
            snprintf((char *)buffer, 64, "second parameter is: %d\r\n", para_int_2);
            esp_at_port_write_data(buffer, strlen((char *)buffer));
        }
    } else {
        // sample code
        // the second parameter is omitted
        // user needs to customize the operation
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "second parameter is omitted\r\n");
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    parse_result = esp_at_get_para_as_str(num_index++, &para_str_3);
    if (parse_result != ESP_AT_PARA_PARSE_RESULT_OMITTED) {
        if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
            return ESP_AT_RESULT_CODE_ERROR;
        } else {
            // sample code
            // user needs to customize the operation
            memset(buffer, 0, 64);
            snprintf((char *)buffer, 64, "third parameter is: %s\r\n", para_str_3);
            esp_at_port_write_data(buffer, strlen((char *)buffer));
        }
    } else {
        // sample code
        // the third parameter is omitted
        // user needs to customize the operation
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "third parameter is omitted\r\n");
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    parse_result = esp_at_get_para_as_str(num_index++, &para_str_4);
    if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    } else {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "fourth parameter is: %s\r\n", para_str_4);
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    return ESP_AT_RESULT_CODE_OK;
}

Note

If the string parameter input is "", it is not omitted.

Omit the Last Parameter¶

Let’s say you want to make the string parameter <param_3> optional, which is also the last parameter.

AT+TEST=<param_1>,<param_2>[,<param_3>]

There are two cases of omission:

AT+TEST=<param_1>,<param_2>
AT+TEST=<param_1>,<param_2>,

Below is the sample code to achieve it:

uint8_t at_setup_cmd_test(uint8_t para_num)
{
    int32_t para_int_1 = 0;
    uint8_t *para_str_2 = NULL;
    uint8_t *para_str_3 = NULL;
    uint8_t num_index = 0;
    uint8_t buffer[64] = {0};
    esp_at_para_parse_result_type parse_result = ESP_AT_PARA_PARSE_RESULT_OK;

    snprintf((char *)buffer, 64, "this cmd is setup cmd and cmd num is: %u\r\n", para_num);
    esp_at_port_write_data(buffer, strlen((char *)buffer));

    parse_result = esp_at_get_para_as_digit(num_index++, &para_int_1);
    if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    } else {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "first parameter is: %d\r\n", para_int_1);
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    parse_result = esp_at_get_para_as_str(num_index++, &para_str_2);
    if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    } else {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "second parameter is: %s\r\n", para_str_2);
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    if (num_index == para_num) {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "third parameter is omitted\r\n");
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    } else {
        parse_result = esp_at_get_para_as_str(num_index++, &para_str_3);
        if (parse_result != ESP_AT_PARA_PARSE_RESULT_OMITTED) {
            if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
                return ESP_AT_RESULT_CODE_ERROR;
            } else {
                // sample code
                // user needs to customize the operation
                memset(buffer, 0, 64);
                snprintf((char *)buffer, 64, "third parameter is: %s\r\n", para_str_3);
                esp_at_port_write_data(buffer, strlen((char *)buffer));
            }
        } else {
            // sample code
            // the third parameter is omitted
            // user needs to customize the operation
            memset(buffer, 0, 64);
            snprintf((char *)buffer, 64, "third parameter is omitted\r\n");
            esp_at_port_write_data(buffer, strlen((char *)buffer));
        }
    }

    return ESP_AT_RESULT_CODE_OK;
}

Note

If the string parameter input is "", it is not omitted.

Block Command Execution¶

Sometimes you want to block the execution of one command to wait for another execution result, and the system may return different values according to the result.

Generally, this kind of command needs to synchronize the results of other tasks.

semaphore is recommended to handle synchronization.

The sample code is as follows:

xSemaphoreHandle at_operation_sema = NULL;

uint8_t at_exe_cmd_test(uint8_t *cmd_name)
{
    uint8_t buffer[64] = {0};

    snprintf((char *)buffer, 64, "this cmd is execute cmd: %s\r\n", cmd_name);

    esp_at_port_write_data(buffer, strlen((char *)buffer));

    // sample code
    // users don't have to create semaphores here
    at_operation_sema = xSemaphoreCreateBinary();
    assert(at_operation_sema != NULL);

    // block command execution
    // wait for another execution result
    // other tasks can call xSemaphoreGive to release the semaphore
    xSemaphoreTake(at_operation_sema, portMAX_DELAY);

    return ESP_AT_RESULT_CODE_OK;
}

Access Input Data from AT Command Port¶

ESP-AT supports accessing input data from AT Command port. It provides two APIs for this purpose.

esp_at_port_enter_specific() sets the callback function which will be called by AT port after receiving the input data.
esp_at_port_exit_specific() deletes the callback function set by esp_at_port_enter_specific.

Approaches to access the data vary depending on whether the data length has been specified or not.

Input Data of Specified Length¶

Assuming that you have specified the data length in <param_1> as follows:

AT+TEST=<param_1>

Below is the sample to access the input data of <param_1> length from AT Command Port:

static xSemaphoreHandle at_sync_sema = NULL;

void wait_data_callback(void)
{
    xSemaphoreGive(at_sync_sema);
}

uint8_t at_setup_cmd_test(uint8_t para_num)
{
    int32_t specified_len = 0;
    int32_t received_len = 0;
    int32_t remain_len = 0;
    uint8_t *buf = NULL;
    uint8_t buffer[64] = {0};

    if (esp_at_get_para_as_digit(0, &specified_len) != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    }

    buf = (uint8_t *)malloc(specified_len);
    if (buf == NULL) {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "malloc failed\r\n");
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    // sample code
    // users don't have to create semaphores here
    if (!at_sync_sema) {
        at_sync_sema = xSemaphoreCreateBinary();
        assert(at_sync_sema != NULL);
    }

    // output input prompt ">"
    esp_at_port_write_data((uint8_t *)">", strlen(">"));

    // set the callback function which will be called by AT port after receiving the input data
    esp_at_port_enter_specific(wait_data_callback);

    // receie input data
    while(xSemaphoreTake(at_sync_sema, portMAX_DELAY)) {
        received_len += esp_at_port_read_data(buf + received_len, specified_len - received_len);

        if (specified_len == received_len) {
            esp_at_port_exit_specific();

            // get the length of the remaining input data
            remain_len = esp_at_port_get_data_length();
            if (remain_len > 0) {
                // sample code
                // if the remaining data length > 0, the actual input data length is greater than the specified received data length
                // users can customize the operation to process the remaining data
                // here is just a simple print out of the remaining data
                esp_at_port_recv_data_notify(remain_len, portMAX_DELAY);
            }

            // sample code
            // output received data
            memset(buffer, 0, 64);
            snprintf((char *)buffer, 64, "\r\nreceived data is: ");
            esp_at_port_write_data(buffer, strlen((char *)buffer));

            esp_at_port_write_data(buf, specified_len);

            break;
        }
    }

    free(buf);

    return ESP_AT_RESULT_CODE_OK;
}

So, if you set AT+TEST=5 and the input data is 1234567890, the ESP-AT output is as follows.

AT+TEST=5
>67890
received data is: 12345
OK

Input Data of Unspecified Length¶

This scenario is similar to the Wi-Fi Passthrough Mode. You do not specify the data length.

AT+TEST

Assuming that ESP-AT ends the execution of the command and returns the execution result, the sample code is as follows:

#define BUFFER_LEN (2048)
static xSemaphoreHandle at_sync_sema = NULL;

void wait_data_callback(void)
{
    xSemaphoreGive(at_sync_sema);
}

uint8_t at_exe_cmd_test(uint8_t *cmd_name)
{
    int32_t received_len = 0;
    int32_t remain_len = 0;
    uint8_t *buf = NULL;
    uint8_t buffer[64] = {0};


    buf = (uint8_t *)malloc(BUFFER_LEN);
    if (buf == NULL) {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "malloc failed\r\n");
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    // sample code
    // users don't have to create semaphores here
    if (!at_sync_sema) {
        at_sync_sema = xSemaphoreCreateBinary();
        assert(at_sync_sema != NULL);
    }

    // output input prompt ">"
    esp_at_port_write_data((uint8_t *)">", strlen(">"));

    // set the callback function which will be called by AT port after receiving the input data
    esp_at_port_enter_specific(wait_data_callback);

    // receie input data
    while(xSemaphoreTake(at_sync_sema, portMAX_DELAY)) {
        memset(buf, 0, BUFFER_LEN);

        received_len = esp_at_port_read_data(buf, BUFFER_LEN);
        // check whether to exit the mode
        // the exit condition is the “+++” string received
        if ((received_len == 3) && (strncmp((const char *)buf, "+++", 3)) == 0) {
            esp_at_port_exit_specific();

            // sample code
            // if the remaining data length > 0, it means that there is still data left in the buffer to be processed
            // users can customize the operation to process the remaining data
            // here is just a simple print out of the remaining data
            remain_len = esp_at_port_get_data_length();
            if (remain_len > 0) {
                esp_at_port_recv_data_notify(remain_len, portMAX_DELAY);
            }

            break;
        } else if (received_len > 0) {
            // sample code
            // users can customize the operation to process the received data
            // here is just a simple print received data
            memset(buffer, 0, 64);
            snprintf((char *)buffer, 64, "\r\nreceived data is: ");
            esp_at_port_write_data(buffer, strlen((char *)buffer));

            esp_at_port_write_data(buf, strlen((char *)buf));
        }
    }

    free(buf);

    return ESP_AT_RESULT_CODE_OK;
}

So, if the first input data is 1234567890, and the second input data is +++, the ESP-AT output is as follows:

AT+TEST
>
received data is: 1234567890
OK

How To Create Factory Parameter Bin¶

Overview¶

In order to adapt the AT firmware to different requirements, for example, different development board, different country code, different RF restriction, we make a table to configure those parameters.

Factory param type¶

The origin table is components/customized_partitions/raw_data/factory_param/factory_param_type.csv, and the factory parameter type is as the following table:

param_name	offset	type	size
platform	-1	String	0
module_name	-1	String	0
description	-1	String	0
magic_flag	0	integer	2
version	2	integer	1
reserved1	3	integer	1
tx_max_power	4	integer	1
uart_port	5	integer	1
start_channel	6	integer	1
channel_num	7	integer	1
country_code	8	String	4
uart_baudrate	12	integer	4
uart_tx_pin	16	integer	1
uart_rx_pin	17	integer	1
uart_cts_pin	18	integer	1
uart_rts_pin	19	integer	1
tx_control_pin	20	integer	1
rx_control_pin	21	integer	1
reserved2	22	String	2
platform	24	String	32
module_name	56	String	32

description:
- prompt information when build the project
version:
- the version of factory param mangement
reserved1
- reserved
tx_max_power
- Wi-Fi maximum tx power
  - For ESP32 Series chip, range[8, 78], more details please refer to ESP32 tx power setting range
  - For ESP8266 Series chip, range[-128, 127], more details please refer to ESP8266 tx power setting range
  - For ESP32S2 Series chip, range[8, 78], more details please refer to ESP32S2 tx power setting range
  - For ESP32-C3 Series chip, range[8, 78], more details please refer to ESP32-C3 tx power setting range
start_chanel
- Wi-Fi start channel
channel_num
- the total channel number of Wi-Fi
country_code
- Country code
uart_baudrate
- uart baudrate
uart_tx_pin
- uart tx pin
uart_rx_pin
- uart rx pin
uart_cts_pin
- uart cts pin, it can be configured -1, if the pin is not used
uart_rts_pin
- uart rts pin, it can be configured -1, if the pin is not used
tx_control_pin
- for some board, tx pin need to be separated from mcu when power on. It can be configured -1, if the pin is not used
rx_control_pin
- for some board, rx pin need to be separated from mcu when power on. It can be configured -1, if the pin is not used
reserved2
- reserved
platform
- Which platform the current firmware runs on
module_name
- Which module the current firmware runs on

Factory param data¶

The origin table is components/customized_partitions/raw_data/factory_param/factory_param_data.csv, and the information each row contains is about one module. The factory parameter data is as the following table:

platform	module_name	description	magic_flag	version	tx_max_power	uart_port	start_channel	channel_num	country_code	uart_baudrate	uart_tx_pin	uart_rx_pin	uart_cts_pin	uart_rts_pin	tx_control_pin	rx_control_pin
PLATFORM_ESP32	WROOM-32		0xfcfc	3	78	1	1	13	CN	115200	17	16	15	14	-1	-1
PLATFORM_ESP32	WROVER-32		0xfcfc	3	78	1	1	13	CN	115200	22	19	15	14	-1	-1
PLATFORM_ESP32	PICO-D4		0xfcfc	3	78	1	1	13	CN	115200	22	19	15	14	-1	-1
PLATFORM_ESP32	SOLO-1		0xfcfc	3	78	1	1	13	CN	115200	17	16	15	14	-1	-1
PLATFORM_ESP32	MINI-1	ESP32-U4WDH chip inside	0xfcfc	3	78	1	1	13	CN	115200	22	19	15	14	-1	-1
PLATFORM_ESP32	ESP32-D2WD	"2MB flash, No OTA"	0xfcfc	3	78	1	1	13	CN	115200	22	19	15	14	-1	-1
PLATFORM_ESP8266	WROOM-02	TX:15 RX:13	0xfcfc	3	78	0	1	13	CN	115200	15	13	3	1	-1	-1
PLATFORM_ESP8266	WROOM-5V2L	5V UART level	0xfcfc	3	78	0	1	13	CN	115200	15	13	3	1	5	-1
PLATFORM_ESP8266	ESP8266_1MB	No OTA	0xfcfc	3	78	0	1	13	CN	115200	15	13	3	1	-1	-1
PLATFORM_ESP8266	WROOM-02-N	TX:1 RX:3	0xfcfc	3	78	0	1	13	CN	115200	1	3	-1	-1	-1	-1
PLATFORM_ESP8266	WROOM-S2		0xfcfc	3	78	0	1	13	CN	115200	15	13	3	1	-1	-1
PLATFORM_ESP32S2	WROOM		0xfcfc	3	78	1	1	13	CN	115200	17	21	20	19	-1	-1
PLATFORM_ESP32S2	WROVER		0xfcfc	3	78	1	1	13	CN	115200	17	21	20	19	-1	-1
PLATFORM_ESP32S2	SOLO		0xfcfc	3	78	1	1	13	CN	115200	17	21	20	19	-1	-1
PLATFORM_ESP32S2	MINI		0xfcfc	3	78	1	1	13	CN	115200	17	21	20	19	-1	-1
PLATFORM_ESP32C3	MINI-1	TX:7 RX:6	0xfcfc	3	78	1	1	13	CN	115200	7	6	5	4	-1	-1

Add customized module¶

if you want to add a module named as “MY_MODULE”, of which country code is JP, and Wi-Fi channel is from 1 to 14, the table should be as the following one:

platform	module_name	description	magic_flag	version	tx_max_power	uart_port	start_channel	channel_num	country_code	uart_baudrate	uart_tx_pin	uart_rx_pin	uart_cts_pin	uart_rts_pin	tx_control_pin	rx_control_pin
PLATFORM_ESP32	WROOM-32		0xfcfc	3	78	1	1	13	CN	115200	17	16	15	14	-1	-1
PLATFORM_ESP32	WROVER-32		0xfcfc	3	78	1	1	13	CN	115200	22	19	15	14	-1	-1
PLATFORM_ESP32	PICO-D4		0xfcfc	3	78	1	1	13	CN	115200	22	19	15	14	-1	-1
PLATFORM_ESP32	SOLO-1		0xfcfc	3	78	1	1	13	CN	115200	17	16	15	14	-1	-1
PLATFORM_ESP32	MINI-1	ESP32-U4WDH chip inside	0xfcfc	3	78	1	1	13	CN	115200	22	19	15	14	-1	-1
PLATFORM_ESP32	ESP32-D2WD	"2MB flash, No OTA"	0xfcfc	3	78	1	1	13	CN	115200	22	19	15	14	-1	-1
PLATFORM_ESP8266	WROOM-02	TX:15 RX:13	0xfcfc	3	78	0	1	13	CN	115200	15	13	3	1	-1	-1
PLATFORM_ESP8266	WROOM-5V2L	5V UART level	0xfcfc	3	78	0	1	13	CN	115200	15	13	3	1	5	-1
PLATFORM_ESP8266	ESP8266_1MB	No OTA	0xfcfc	3	78	0	1	13	CN	115200	15	13	3	1	-1	-1
PLATFORM_ESP8266	WROOM-02-N	TX:1 RX:3	0xfcfc	3	78	0	1	13	CN	115200	1	3	-1	-1	-1	-1
PLATFORM_ESP8266	WROOM-S2		0xfcfc	3	78	0	1	13	CN	115200	15	13	3	1	-1	-1
PLATFORM_ESP32S2	WROOM		0xfcfc	3	78	1	1	13	CN	115200	17	21	20	19	-1	-1
PLATFORM_ESP32S2	WROVER		0xfcfc	3	78	1	1	13	CN	115200	17	21	20	19	-1	-1
PLATFORM_ESP32S2	SOLO		0xfcfc	3	78	1	1	13	CN	115200	17	21	20	19	-1	-1
PLATFORM_ESP32S2	MINI		0xfcfc	3	78	1	1	13	CN	115200	17	21	20	19	-1	-1
PLATFORM_ESP32C3	MINI-1	TX:7 RX:6	0xfcfc	3	78	1	1	13	CN	115200	7	6	5	4	-1	-1
MY_PLATFORM	MY_MODULE	MY_DESCRIPTION	0xfcfc	3	78	1	1	14	JP	115200	17	16	15	14	-1	-1

Then add module information in esp_at_module_info in at_default_config.c, like

static const esp_at_module_info_t esp_at_module_info[] = {
#if defined(CONFIG_IDF_TARGET_ESP32)
    {"WROOM-32",        CONFIG_ESP_AT_OTA_TOKEN_WROOM32,       CONFIG_ESP_AT_OTA_SSL_TOKEN_WROOM32 },        // default:ESP32-WROOM-32
    {"WROOM-32",        CONFIG_ESP_AT_OTA_TOKEN_WROOM32,       CONFIG_ESP_AT_OTA_SSL_TOKEN_WROOM32 },        // ESP32-WROOM-32
    {"WROVER-32",       CONFIG_ESP_AT_OTA_TOKEN_WROVER32,      CONFIG_ESP_AT_OTA_SSL_TOKEN_WROVER32 },       // ESP32-WROVER
    {"PICO-D4",         CONFIG_ESP_AT_OTA_TOKEN_ESP32_PICO_D4, CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32_PICO_D4},   // ESP32-PICO-D4
    {"SOLO-1",          CONFIG_ESP_AT_OTA_TOKEN_ESP32_SOLO_1,  CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32_SOLO_1 },   // ESP32-SOLO-1
    {"MINI-1",          CONFIG_ESP_AT_OTA_TOKEN_ESP32_MINI_1,  CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32_MINI_1 },   // ESP32-MINI-1
#endif

#if defined(CONFIG_IDF_TARGET_ESP8266)
    {"WROOM-02",        CONFIG_ESP_AT_OTA_TOKEN_WROOM_02,       CONFIG_ESP_AT_OTA_SSL_TOKEN_WROOM_02 },
    {"WROOM-S2",        CONFIG_ESP_AT_OTA_TOKEN_WROOM_S2,       CONFIG_ESP_AT_OTA_SSL_TOKEN_WROOM_S2 },
#endif

#if defined(CONFIG_IDF_TARGET_ESP32S2)
    {"WROOM",        CONFIG_ESP_AT_OTA_TOKEN_ESP32S2_WROOM,       CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32S2_WROOM },
    {"WROVER",       CONFIG_ESP_AT_OTA_TOKEN_ESP32S2_WROVER,      CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32S2_WROVER },
    {"SOLO",         CONFIG_ESP_AT_OTA_TOKEN_ESP32S2_SOLO,        CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32S2_SOLO },
    {"MINI",         CONFIG_ESP_AT_OTA_TOKEN_ESP32S2_MINI,        CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32S2_MINI },
#endif

#if defined(CONFIG_IDF_TARGET_ESP32C3)
    {"MINI-1",         CONFIG_ESP_AT_OTA_TOKEN_ESP32C3_MINI,        CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32C3_MINI },
#endif
};

Add customized data¶

If you want to add more parameter, for example, add a string “20181225” as the date, you need to add the type of date in the factory_param_type.csv, as the following table.

param_name	offset	type	size
platform	-1	String	0
module_name	-1	String	0
description	-1	String	0
magic_flag	0	integer	2
version	2	integer	1
reserved1	3	integer	1
tx_max_power	4	integer	1
uart_port	5	integer	1
start_channel	6	integer	1
channel_num	7	integer	1
country_code	8	String	4
uart_baudrate	12	integer	4
uart_tx_pin	16	integer	1
uart_rx_pin	17	integer	1
uart_cts_pin	18	integer	1
uart_rts_pin	19	integer	1
tx_control_pin	20	integer	1
rx_control_pin	21	integer	1
reserved2	22	String	2
platform	24	String	32
module_name	56	String	32
date	88	String	8

Edit factory_param_data.csv with reference to Add customized module, and add the date into the last column, as the following table,

platform	module_name	description	magic_flag	version	reserved1	tx_max_power	uart_port	start_channel	channel_num	country_code	uart_baudrate	uart_tx_pin	uart_rx_pin	uart_cts_pin	uart_rts_pin	tx_control_pin	rx_control_pin
PLATFORM_ESP32	WROOM-32		0xfcfc	3	0	78	1	1	13	CN	115200	17	16	15	14	-1	-1
PLATFORM_ESP32	WROVER-32		0xfcfc	3	0	78	1	1	13	CN	115200	22	19	15	14	-1	-1
PLATFORM_ESP32	PICO-D4		0xfcfc	3	0	78	1	1	13	CN	115200	22	19	15	14	-1	-1
PLATFORM_ESP32	SOLO-1		0xfcfc	3	0	78	1	1	13	CN	115200	17	16	15	14	-1	-1
PLATFORM_ESP32	MINI-1	ESP32-U4WDH chip inside	0xfcfc	3	0	78	1	1	13	CN	115200	22	19	15	14	-1	-1
PLATFORM_ESP32	ESP32-D2WD	"2MB flash, No OTA"	0xfcfc	3	0	78	1	1	13	CN	115200	22	19	15	14	-1	-1
PLATFORM_ESP8266	WROOM-02	TX:15 RX:13	0xfcfc	3	0	78	0	1	13	CN	115200	15	13	3	1	-1	-1
PLATFORM_ESP8266	WROOM-5V2L	5V UART level	0xfcfc	3	0	78	0	1	13	CN	115200	15	13	3	1	5	-1
PLATFORM_ESP8266	ESP8266_1MB	No OTA	0xfcfc	3	0	78	0	1	13	CN	115200	15	13	3	1	-1	-1
PLATFORM_ESP8266	WROOM-02-N	TX:1 RX:3	0xfcfc	3	0	78	0	1	13	CN	115200	1	3	-1	-1	-1	-1
PLATFORM_ESP8266	WROOM-S2		0xfcfc	3	0	78	0	1	13	CN	115200	15	13	3	1	-1	-1
PLATFORM_ESP32S2	WROOM		0xfcfc	3	0	78	1	1	13	CN	115200	17	21	20	19	-1	-1
PLATFORM_ESP32S2	WROVER		0xfcfc	3	0	78	1	1	13	CN	115200	17	21	20	19	-1	-1
PLATFORM_ESP32S2	SOLO		0xfcfc	3	0	78	1	1	13	CN	115200	17	21	20	19	-1	-1
PLATFORM_ESP32S2	MINI		0xfcfc	3	0	78	1	1	13	CN	115200	17	21	20	19	-1	-1
PLATFORM_ESP32C3	MINI-1	TX:7 RX:6	0xfcfc	3	0	78	1	1	13	CN	115200	7	6	5	4	-1	-1
MY_PLATFORM	MY_MODULE	MY_DESCRIPTION	0xfcfc	2	5	78	1	1	14	JP	115200	17	16	15	14	-1	-1

It is important to know that the total size of the AT factory parameter is controlled by the ESP_AT_FACTORY_PARAMETER_SIZE in at_default_config.h, and can be adjusted as needed

Notes: It’s recommended that do not change the first 2048 bytes, which may be used by Espressif.

Then, you can add code to parse date in esp_at_factory_parameter_init or other api.

Modify Factory param data¶

If you simply need to modify factory_param on an existing module, the following three methods are recommended:

method one
- Premise: you need to have the entire esp-at project.

Find the factory_param_data.csv file through the following path: components/customized_partitions/raw_data/factory_param/factory_param_data.csv, and modify the parameters.
Recompile the esp-at project, download the new factory_param.bin into flash.

method two
- Premise: you need to have the entire esp-at project.

Find the factory_param_data.csv file through the following path: components/customized_partitions/raw_data/factory_param/factory_param_data.csv, and modify the parameters.
Open the terminal in the following path: esp-at, execute the following command.
- Commandline: python tools/factory_param_generate.py --platform PLATFORM_ESP32S2 --module WROVER --define_file components/customized_partitions/raw_data/factory_param/factory_param_type.csv --module_file components/customized_partitions/raw_data/factory_param/factory_param_data.csv --bin_name factory_param.bin --log_file ./factory_parameter.log
- The value of the -- platform -- module parameter in the command needs to be changed as the case may be.
It will generate factory_param.bin at esp-at folder, download the new factory_param.bin into flash.
If you want to know how to use the commands in step 2, you can study the factory_param_generate.py file in the ‘esp-at/tools’’.

method three
- Premise: you need to have the factory_param.bin file.

Open this file directly with a binary tool, and directly modify the parameters in the corresponding position according to the parameters offset in factory_param_type.csv.
Download the new factory_param.bin into flash.

How To Customize ble services¶

Where is the `BLE Services` source file¶

The path of BLE service source file is esp-at/components/customized_partitions/raw_data/ble_data/example.csv. If user wants to customize the BLE services, You need to:

Modify the BLE Service file
use esp-at/tools/BLEService.py to generate ble_data.bin
Download generated ble_data.bin to address defined in module_config/module_esp32_default/partitions_at.csv(ESP32 modules).

Description of the structure of the BLE service¶

The BLE Services are defined as a multivariate array of GATT structures, each element of the array always consist of a service, declarations, characteristics and optional descriptors.

User can define more than one services. For example, if you want to define three services(Server_A, Server_B and Server_C), then these three services need to be arranged in order. Since the definition of each service is similar, here we define one service as example, and then you can define others one by one accordingly.

Each service always consist of a service definition and several characteristics. Each characteristic may be followed by some descriptions.

the service definition must be in the first line, it always be a primary service (UUID 0x2800) which determines with its value which service is described(for example, a predefined one such as 0x180A or a self generated one).

For example, the following line defines a primary service with UUID 0xA002.

index	uuid_len	uuid	perm	val_max_len	val_cur_len	value
0	16	0x2800	0x01	2	2	A002

Definition of characteristics starts from the second line. It contains at least two lines, one is the characteristic declaration, another is to define the characteristic. UUID 0x2803 means the characteristic declaration, value of this line sets its permission, for example, 02 means both readable and writable, user can keep this configuration. Then the next line defines this characteristic, UUID of this line will be the characteristic’s UUID, you can define it as you need, value will be the characteristic’s value.

For example, the following lines define a readable and writable characteristic with UUID 0xC300, whose value is 0x30.

index	uuid_len	uuid	perm	val_max_len	val_cur_len	value
1	16	0x2803	0x01	1	1	02
2	16	0xC300	0x01	1	1	30

The attribute can be described further by descriptors. A special one is the descriptor “Client Characteristic Configuration” (UUID 0x2902) which should be present if the Notify bit has been activated in the Characteristic Declaration (UUID 0x2803). This descriptor should always be writable and readable.

For example, the following lines define a readable and writable characteristic with UUID 0xC306, and able to notify.

index	uuid_len	uuid	perm	val_max_len	val_cur_len	value
3	16	0x2803	0x01	1	1	02
4	16	0xC306	0x01	1	1	30
5	16	0x2902	0x011	2	2	0000

The Secondary Partitions Table¶

Overview¶

The primary partition table is for system usage, it will generate a “partitions_at.bin” according to the “partitions_at.csv” in compilation. And if the primary partition table goes wrong, the system will fail to startup. So generally, we should not change the “partitions_at.csv”.

In this case, we provide a secondary partition table for custom usage, “at_customize.csv”. We have already defined some user partitions in it. Custom can add new partitions in the “at_customize.csv”, and generate a new “at_customize.bin” according to it. The partition table can be updated by flashing the new “at_customize.bin” into flash, or be revised by command “AT+SYSFLASH”.

How to use the secondary partition table¶

Enter the project esp32-at, run command python esp-idf/components/partition_table/gen_esp32part.py -q at_customize.csv at_customize.bin to generate a “at_customize.bin”.
Download the “at_customize.bin” into flash, the default address is 0x20000.

Notes of revising at_customize.csv¶

Users should not change the “name” and “type” of the user partitions which we defined in the “at_customize.csv”. But “offset” and “size” can be changed, if necessary.
If you need to add a new user partition, please check if it has already been defined in the ESP-IDF (esp_partition.h) first.
- If it is defined in the ESP-IDF, you should keep the “type” value to be the same when adding it into the at_customize.csv.
- If it is not defined in the ESP-IDF, please set the “type” to be “0x40” when adding it into the at_customize.csv.
A user partition’s name should NOT be longer than 16 bytes.
The default size of the entire “at_customize” partition is 0xE0000, which is defined in the first partition. Please do NOT over the range when adding new user partitions.

When a “at_customize.bin” is needed¶

To use below AT commands, the “at_customize.bin” should be downloaded into flash.

AT+SYSFLASH — Set User Partitions in Flash
AT+FS — Filesystem Operations
SSL server relevant commands
BLE server relevant commands

How to use ESP-AT Classic Bluetooth¶

Overview¶

Classic bluetooth is Disabled by default. If you want to use classic bluetooth commands, you need to enable BT commands in menuconfig.

Component config -> AT -> [*] AT bt command support.

Command Description¶

initialization¶

There are two initialization-related commands. Firstly, initializing the bluetooth protocol stack, and then initializing the profile, such as:

AT+BTINIT=1      // init BT statck
AT+BTSPPINIT=2   // init SPP profile, the role is slave

Basic parameters setting¶

After initialization, there are some basic parameter setting commands that may be need to be invoked.

1. device name¶

The default device name is esp32, If use command to set the device name, it will be stored in NVS.

AT+BTNAME="EXAMPLE"

2. scan mode¶

Sets whether it can be discovered and connected.

AT+BTSCANMODE=2    // both discoverable and connectable

3. security parameters¶

ESP32 supports both Simple pair and Legacy pair by default.

Using this command, you can set the IO capability, PIN type and PIN code of the device.

AT+BTSECPARAM=3,1,"9527"  // NO input NO output, fixed PIN code, 9527

If the PIN type is variable, the PIN code will be ignored. If use the Simple pair encryption, the PIn code will be ignored.

BT SPP EXAMPLE¶

1. PC CONNECTS TO ESP32¶

In this case, generally PC is master and ESP32 is slave. ESP32 needs to do this before the connection is established:

initialization

AT+BTINIT=1     // init BT stack
AT+BTSPPINIT=2  // init spp profile as shave
AT+BTSPPSTART   // if role is client, this command is not required

parameters setting

AT+BTNAME="EXAMPLE"       // set device name
AT+BTSCANMODE=2           // discoverable and connectable
AT+BTSECPARAM=3,1,"9527"  // NoInputNoOutput, fixed PIN code

At this point, the PC should be able to find the bluetooth device with name “EXAMPLE”. If the PC initiates a connection and the connection succeed, ESP32 will print this log:

+BTSPPCONN:<conn index>,<remote_addr>

ESP32 can also initiate connections, before initiating a connection, please scan the surrounding devices at first:

// General inquiry mode, inquiry duration: 10, inquiry response: 10
AT+BTSTARTDISC=0,10,10

The scanning results are as follows:

+BTSTARTDISC:<bt_addr>,<dev_name>,<major_dev_class>,<minor_dev_class>,<major_srv_class>

Initiate the connection using the connection command：

// conn_index: 0, sec_mode: 0 -> No security, remote_address
AT+BTSPPCONN=0,0,"24:0a:c4:09:34:23"

After the connection is established, the data can be sent and received：

// conn_index: 0, data length: 30
AT+BTSPPSEND=0,30

>
OK

If you want to enter passthrough mode:

AT+BTSPPSEND

If you want to exit passthrough mode, you can input +++.

ESP32 CONNECTS TO ESP32¶

If you use two ESP32 boards connected to each other，The process is basically the same as described above, The only difference is the initialization. the client initialization is as follow:

AT+BTINIT=1     // init BT stack
AT+BTSPPINIT=1  // init spp profile as master

All other steps are the same as described above.

How to enable ESP-AT Ethernet¶

Overview¶

Initialises the Ethernet interface and enables it, then sends DHCP requests and tries to obtain a DHCP lease. If successful then you will be able to ping the device.

PHY Configuration¶

Use ./build.py menuconfig to set the PHY model. These configuration items will vary depending on the hardware configuration you are using.

The default configuration is correct for Espressif’s Ethernet board with TP101 PHY. ESP32 AT supports up to four Ethernet PHY: LAN8720, IP101, DP83848 and RTL8201. TLK110 PHY is no longer supported because TI stoped production. If you want to use other phy, follow the document to design.

Compiling¶

./build.py menuconfig -> Component config -> AT -> AT ethernet support to enable ethernet.
./build.py menuconfig -> Component config -> AT -> Ethernet PHY to choose ethernet.
Recompile the esp-at project, download AT bin into flash.

How to Add a New Platform¶

Since the esp-at project supports different platform, for example, ESP32 UART AT, ESP32 SDIO AT, even supports ESP8266 AT, when compiling the esp-at project, users can set different configurations to generate AT firmware for different ESP modules. The detailed information are in the esp-at/module_config directory. Default configuration is the “PLATFORM_ESP32” for ESP-WROOM-32.
Please note that if you use a different bus (for example, SDIO, SPI or other buses) instead of UART, then you cannot use the default module_espxxxx_default directly, you need to re-configure it in the menuconfig.
Herein, we provide an example of the ESP32 SDIO AT to show how to set a new platform for the esp-at project.

1. Create a New Platform¶

For example, to name the platform as “PLATFORM_ESP32”, the module as “WROOM32-SDIO”, we need to open the components/customized_partitions/raw_data/factory_param/factory_param_data.csv and add a new row of the new platform at the end.

platform	module_name	magic_flag	version	module_id	tx_max_power	start_channel	channel_num	country_code	uart_baudrate	uart_tx_pin	uart_rx_pin	uart_ctx_pin	uart_rts_pin	tx_control_pin	rx_control_pin
-xxx-	-xxx-	-xxx-	-xxx-	-xxx-	-xxx-	-xxx-	-xxx-	-xxx-	-xxx-	-xxx-	-xxx-	-xxx-	-xxx-	-xxx-	-xxx-
PLATFORM_ESP32	ESP32-SDIO	0xfcfc	1	1	1	1	13	CN	-1	-1	-1	-1	-1	-1	-1

2. Set Makefile¶

Open the Makefile and set to the new platform. Please use capital letters.

export ESP_AT_PROJECT_PLATFORM ?= PLATFORM_ESP32
export ESP_AT_MODULE_NAME ?= ESP32-SDIO

3. Configure the New Platform¶

3.1. Enter module_config folder, copy the module_esp32_default to make a new module_esp32-sdio.
3.2. In this example, we need not to change the partition table and the ESP-IDF version, so the at_customize.csv, IDF_VERSION and partitions_at.csv all need not to be changed.

3.3. Revise the sdkconfig.defaults

Configure to use the partition table in the module_esp32-sdio folder, revise the following items：

CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="module_config/module_esp32-sdio/partitions_at.csv"

CONFIG_PARTITION_TABLE_FILENAME="module_config/module_esp32-sdio/partitions_at.csv"

CONFIG_AT_CUSTOMIZED_PARTITION_TABLE_FILE="module_config/module_esp32-sdio/at_customize.csv"

Since the esp-at project already supports the SDIO configuration, we only need to add it into the sdkconfig.defaults.
- Remove the UART AT configuration in the sdkconfig.defaults.
```
CONFIG_AT_BASE_ON_UART=y
CONFIG_AT_UART_PORT=1
CONFIG_AT_UART_PORT_RX_PIN=16
CONFIG_AT_UART_PORT_TX_PIN=17
CONFIG_AT_UART_PORT_RTS_PIN=14
CONFIG_AT_UART_PORT_CTS_PIN=15
```
And add the following configuration.
```
CONFIG_AT_BASE_ON_SDIO=y
```

4. Revise the at_core lib¶

Since the ESP32 SDIO AT and the ESP32 UART AT are based on the same platform, ESP32, they will share the same at_core.lib. In this case, we need not to add any new at_core lib.
If you need to use a new at_core lib, put the lib into the components/at/lib, rename the lib as libxxxx_at_core.a, xxxx is the platform name. For example, if you set the ESP_AT_PROJECT_PLATFORM ?= PLATFORM_ESP8848 in the Makefile in Step 2, then the lib should be named as libesp8848_at_core.a.

ESP32 SDIO AT Guide¶

Overview¶

SDIO AT is based on ESP32 AT, using SDIO, instead of UART, to communicate with host MCU. The ESP32 SDIO AT runs as an SDIO slave.
SDIO communication needs at least 4 pins: CMD, CLK, DAT0, DAT1;

for one line mode, DAT1 runs as the interrupt pin;
for four lines mode, two more pins (DAT2 and DAT3) are needed.

SDIO SLAVE pins is as below:

CLK is GPIO14
CMD is GPIO15
DAT0 is GPIO2
DAT1 is GPIO4
DAT2 is GPIO12 (for four lines mode only)
DAT3 is GPIO13 (for four lines mode only)

Flashing Firmware¶

ESP-SDIO-TESTBOARD-V1¶

Turn switch 1, 2, 3, 4, 5 “ON”; and others are “OFF”.
Flashing firmware to the master. After the flashing completed, the light on ESP32 slave will turn on, it means that the master runs successfully, and power on the slave.
Flashing the SDIO AT firmware to the slave.

Note:
If you use ESP32-DevKitC or ESP-WROVER-KIT V2 (or earlier versions), please refer to the board-compatibility to set strapping pins, and run the SDIO demo firstly, to make sure the SDIO communication works properly. If it is, then you can start your SDIO AT journey.

SDIO Data Transimission¶

SDIO HOST¶

Power on the SDIO SLAVE (this step is for ESP-SDIO-TESTBOARD-V1 only)
- ESP-SDIO-TESTBOARD-V1 contains one master and three slaves (ESP32, ESP8266 and ESP8089).
- To use ESP32 as SDIO slave, you need to pull down GPIO5, see slave_power_on.
Intialize SDIO HOST
- To initialize SDIO, including configure one line or four lines mode, SDIO frequency, initialize SD mode.
Negotiate SDIO Communication
- Negotiate SDIO parameters with the slave according to SDIO spec. Please note that SDIO HOST must wait till the slave startup done, then to start the negotiation. Usually the host needs to delay some time to wait.
Receive Data
- When the SDIO host detects an interrupt from DAT1, if it is the slave sends new packet to the host, the host will read those data by CMD53.
Send Data
- In SDIO AT demo, the data inputs from serial port, when the SDIO host gets it, the host will send it to the slave through SDIO by CMD53.
- Please note that if the sending time out, there may be something wrong with the slave, then we will re-initiate both SDIO host and slave.
- Also, after AT+RST or AT+RESTORE, both SDIO host and slave should be initiated again.

SDIO SLAVE¶

When SDIO slave receives data from SDIO host, the slave will inform the AT core and give the data to the AT core to handle. After the AT core finished the work, the slave will send data to the host as feedback.

Initialize SDIO Slave
- Call sdio_slave_initialize to initialize SDIO slave driver
- Call sdio_slave_recv_register_buf to register receiving buffer. To make it receive data faster, you can register multiple buffers.
- Call sdio_slave_recv_load_buf to load the receiving buffer, ready to receive data.
- Call sdio_slave_set_host_intena to set interrupt for host, which mainly used is the SDIO_SLAVE_HOSTINT_SEND_NEW_PACKET, to notify that there is a new packet sent from the host.
- Call sdio_slave_start to start SDIO hardware transmission.
Send Data
- Since the SDIO slave data transmission via DMA, you need to copy the data from AT core to the memory which DMA can read firstly.
- Call sdio_slave_transmit to send the data.
Receive Data
- To speed up the data transmission, after receiving data by sdio_slave_recv, we use a circular linked list to transmit the received data to the AT core.

SPI AT Guide¶

[中文]

ESP8266 AT does not support SPI transmission. It is recommended to use ESP32-C3 AT for SPI transmission. For details, please refer to ESP32-C3 SPI AT Guide.

How to implement OTA update¶

The following steps guide the users in creating a device on iot.espressif.cn and updating the OTA BIN on it.

Open the website http://iot.espressif.cn. If using SSL OTA, it should be https://iot.espressif.cn.

Open iot.espressif.cn website¶
Click “Join” in the upper right corner of the webpage, and enter your name, email address, and password.

Join iot.espressif.cn website¶
Click on “Device” in the upper right corner of the webpage, and click on “Create” to create a device.

Click on “Device”¶

Click on “Create”¶
A key is generated when the device is successfully created, as the figure below shows.

A key has been generated¶
Use the key to compile your own OTA BIN. The process of configuring the AT OTA token key is as follows:

Configuring the AT OTA token key - Step 1¶

Configuring the AT OTA token key - Step 2 and 3¶

Note

If using SSL OTA, the option “OTA based upon ssl” should be selected.
Click on “Product” to enter the webpage, as shown below. Click on the device created. Enter version and corename under “ROM Deploy”. Rename the BIN compiled in Step 5 as “ota.bin” and save the configuration.

Enter version and corename¶
Click on the ota.bin to save it as the current version.

Save the current version of ota.bin¶
Run the command AT+CIUPDATE on the ESP device. If the network is connected, OTA update will be done.

How to update the esp-idf version¶

The esp-at project supports two platforms by default, ESP32 UART AT and ESP8266 UART AT. Each of the platform has a set of configurations, you can configure its directory by setting the ESP_AT_MODULE_CONFIG_DIR in the Makefile. The default directory of ESP32 UART AT is module_config/module_esp32_default, and the ESP8266 UART AT is module_config/module_esp8266_default, version information is in the file IDF_VERSION. For example, the version info of module_esp32_default is:

branch:master
commit:7fa98593bc179ea50a1bc8244d5b94bac59c9a10
repository:https://github.com/espressif/esp-idf.git

branch: branch of the idf
commit: commit id of the idf
repository: url of the idf

To update the idf/SDK, you need to change the branch, commit and repository to be the ones that you want to update to.

It is suggested that you can delete the original idf/SDK after updating the file IDF_VERSION. In this case, the esp-at will clone the new idf/SDK according to the file IDF_VERSION firstly in next compilation.

Notice: If you changed the repository url in the file IDF_VERSION, then you have to delete the original idf/SDK in the project. Otherwise, the update may fail.

How to understand the differences of each type of module¶

Since the esp-at project supports different module, for example, WROOM-32, WROVER-32, ESP8266_1MB, even supports WROOM-5V2L, when compiling the esp-at project, users can set different configurations to generate AT firmware for different ESP modules. The detailed information are in the esp-at/module_config directory.
In order to facilitate customers to understand the differences between different modules of the same platform, they will be summarized in the following list.

1. ESP32 Platform¶

1. Command differences supported¶

command	ESP32-WROOM-32_AT_Bin	ESP32-WROVER-32_AT_Bin	ESP32-PICO-D4_AT_Bin	ESP32-SOLO-1_AT_Bin	ESP32-D2WD_AT_Bin
AT base command support	√	√	√	√	√
AT wifi command support	√	√	√	√	√
AT MDNS command support	√	√	√	√	√
AT net command support	√	√	√	√	√
AT WPS command support	√	√	√	√	√
AT ping command support	√	√	√	√	√
AT smartconfig command support	√	√	√	√	√
AT MQTT command support	√	√	√	√	√
AT http command support	√	√	√	√	√
AT ble command support	√	√	√	√	√
AT ble hid command support	√	√	√	√	√
AT blufi command support	×	×	×	×	×
AT bt spp command support	×	√	×	×	×
AT bt a2dp command support	×	×	×	×	×
AT ethernet support	×	×	×	×	×
AT FS command support	×	×	×	×	×
AT driver command support	×	×	×	×	×
AT WPA2 Enterprise command support	×	×	×	×	×
AT OTA command support	√	√	√	√	×

2. Hardware differences¶

	ESP32-WROOM-32_AT_Bin	ESP32-WROVER-32_AT_Bin	ESP32-PICO-D4_AT_Bin	ESP32-SOLO-1_AT_Bin	ESP32-D2WD_AT_Bin
flash_size(MB)	4	4	4	4	2
PSRAM(MB)	×	8	×	×	×
UART level(Volt)	3.3	3.3	3.3	3.3	3.3
UART pin(TX,RX,CTS,RTS)	17, 16, 15, 14	22, 19, 15, 14	22, 19, 15, 14	17, 16, 15, 14	22, 19, 15, 14

For factory param, see: components/customized_partitions/raw_data/factory_param/factory_param_data.csv

3. AT pin¶

See: https://docs.espressif.com/projects/esp-at/en/latest/AT_Binary_Lists/index.html

4. Firmware supported modules¶

module/chip	ESP32-WROOM-32_AT_Bin	ESP32-WROVER-32_AT_Bin	ESP32-PICO-D4_AT_Bin	ESP32-SOLO-1_AT_Bin	ESP32-D2WD_AT_Bin
ESP32-WROOM-32E	√	×	√	√	√
ESP32-WROOM-32UE	√	×	√	√	√
ESP32-WROOM-32D	√	×	√	√	√
ESP32-WROOM-32U	√	×	√	√	√
ESP32-WROOM-32	√	×	√	√	√
ESP32-WROOM-32SE	×	×	×	×	×
ESP32-WROVER-E	×	√	√	×	√
ESP32-WROVER-IE	×	√	√	×	√
ESP32-WROVER-B	×	√	√	×	√
ESP32-WROVER-IB	×	√	√	×	√
ESP32-WROVER	×	√	√	×	√
ESP32-WROVER-I	×	√	√	×	√
ESP32-SOLO-1	√	×	√	√	√
ESP32-D2WD	×	×	×	×	√
ESP32-MINI-1	×	×	√	×	√
ESP32-PICO-D4	×	×	√	×	√

2. ESP8266 Platform¶

1. Command differences supported¶

command	ESP8266-WROOM-02_AT_Bin	ESP8266-WROOM-5V2L_AT_Bin	ESP8266_1MB_AT_Bin	ESP8266-WROOM-02-N_AT_Bin
AT base command support	√	√	√	√
AT wifi command support	√	√	√	√
AT MDNS command support	√	√	√	√
AT WPS command support	√	√	√	√
AT ping command support	√	√	√	√
AT smartconfig command support	√	√	√	√
AT MQTT command support	√	√	√	√
AT http command support	×	×	×	×
AT signaling test command support	√	√	√	√
AT WPA2 Enterprise command support	×	×	×	×
AT OTA command support	√	√	×	√

2. Hardware differences¶

	ESP8266-WROOM-02_AT_Bin	ESP8266-WROOM-5V2L_AT_Bin	ESP8266_1MB_AT_Bin	ESP8266-WROOM-02-N_AT_Bin
flash_size(MB)	2	2	1	2
PSRAM(MB)	×	×	×	×
UART level(Volt)	3.3	5	3.3	3.3
UART pin(TX,RX,CTS,RTS)	15, 13, 3, 1	15, 13, 3, 1	15, 13, 3, 1	1, 3, -1, -1

For factory param, see: components/customized_partitions/raw_data/factory_param/factory_param_data.csv

3. AT pin¶

See: https://docs.espressif.com/projects/esp-at/en/latest/AT_Binary_Lists/index.html

4. Firmware supported modules¶

module/chip	ESP8266-WROOM-02_AT_Bin	ESP8266-WROOM-5V2L_AT_Bin	ESP8266_1MB_AT_Bin	ESP8266-WROOM-02-N_AT_Bin
ESP-WROOM-02D	√	×	√	√
ESP-WROOM-02U	√	×	√	√
ESP-WROOM-02	√	×	√	√
ESP-WROOM-5V2L	×	√	×	×
ESP-WROOM-S2	×	×	×	×
ESP8285N08	×	×	√	×
ESP8285H08	×	×	√	×
ESP8285H16	√	×	√	√

3. ESP32S2 Platform¶

1. Command differences supported¶

command	ESP32-S2-WROOM_AT_Bin	ESP32-S2-WROVER_AT_Bin	ESP32-S2-SOLO_AT_Bin	ESP32-S2-MINI_AT_Bin
AT base command support	√	√	√	√
AT wifi command support	√	√	√	√
AT net command support	√	√	√	√
AT MDNS command support	√	√	√	√
AT WPS command support	√	√	√	√
AT ping command support	√	√	√	√
AT smartconfig command support	√	√	√	√
AT MQTT command support	√	√	√	√
AT http command support	√	√	√	√
AT FS command support	×	×	×	×
AT driver command support	×	×	×	×
AT WPA2 Enterprise command support	×	×	×	×
AT OTA command support	√	√	√	√

2. Hardware differences¶

	ESP32-S2-WROOM_AT_Bin	ESP32-S2-WROVER_AT_Bin	ESP32-S2-SOLO_AT_Bin	ESP32-S2-MINI_AT_Bin
flash_size(MB)	2	2	2	2
PSRAM(MB)	×	×	×	×
UART level(Volt)	3.3	3.3	3.3	3.3
UART pin(TX,RX,CTS,RTS)	17, 21, 20, 19	17, 21, 20, 19	17, 21, 20, 19	17, 21, 20, 19

For factory param, see: components/customized_partitions/raw_data/factory_param/factory_param_data.csv

3. AT pin¶

See: https://docs.espressif.com/projects/esp-at/en/latest/AT_Binary_Lists/index.html

4. Firmware supported modules¶

module/chip	ESP32-S2-WROOM_AT_Bin	ESP32-S2-WROVER_AT_Bin	ESP32-S2-SOLO_AT_Bin	ESP32-S2-MINI_AT_Bin
ESP32-S2-WROOM	√	√	√	√
ESP32-S2-WROOM-I	√	√	√	√
ESP32-S2-WROVER	√	√	√	√
ESP32-S2-WROVER-I	√	√	√	√
ESP32-S2-SOLO	√	√	√	√
ESP32-S2-SOLO-U	√	√	√	√
ESP32-S2-MINI-1	√	√	√	√
ESP32-S2-MINI-1U	√	√	√	√

4. ESP32-C3 Platform¶

1. Command differences supported¶

command	ESP32-C3-MINI-1_AT_Bin
AT base command support	√
AT wifi command support	√
AT MDNS command support	√
AT net command support	√
AT WPS command support	√
AT ping command support	√
AT smartconfig command support	√
AT MQTT command support	√
AT http command support	√
AT ble command support	×
AT ble hid command support	×
AT blufi command support	×
AT bt spp command support	×
AT bt a2dp command support	×
AT ethernet support	×
AT FS command support	×
AT driver command support	×
AT WPA2 Enterprise command support	×
AT OTA command support	√
AT WEB Server command support	×

2. Hardware differences¶

	ESP32-C3-MINI-1_AT_Bin
flash_size(MB)	4
PSRAM(MB)	×
UART level(Volt)	3.3
UART pin(TX,RX,CTS,RTS)	7, 6, 5, 4

For factory param, see: components/customized_partitions/raw_data/factory_param/factory_param_data.csv

3. AT pin¶

See: https://docs.espressif.com/projects/esp-at/en/latest/AT_Binary_Lists/index.html

4. Firmware supported modules¶

module/chip	ESP32-C3-MINI-1_AT_Bin
ESP32-C3-MINI-1	√

AT API Reference¶

Header File¶

at/include/esp_at_core.h

Functions¶

void esp_at_module_init(uint32_t netconn_max, const uint8_t *custom_version)¶

This function should be called only once, before any other AT functions are called.

Parameters

netconn_max: the maximum number of the link in the at module
custom_version: version information by custom

esp_at_para_parse_result_type esp_at_get_para_as_digit(int32_t para_index, int32_t *value)¶

Parse digit parameter from command string.

Return

ESP_AT_PARA_PARSE_RESULT_OK : succeed
ESP_AT_PARA_PARSE_RESULT_FAIL : fail
ESP_AT_PARA_PARSE_RESULT_OMITTED : this parameter is OMITTED

Parameters

para_index: the index of parameter
value: the value parsed

esp_at_para_parse_result_type esp_at_get_para_as_str(int32_t para_index, uint8_t **result)¶

Parse string parameter from command string.

Return

ESP_AT_PARA_PARSE_RESULT_OK : succeed
ESP_AT_PARA_PARSE_RESULT_FAIL : fail
ESP_AT_PARA_PARSE_RESULT_OMITTED : this parameter is OMITTED

Parameters

para_index: the index of parameter
result: the pointer that point to the result.

void esp_at_port_recv_data_notify_from_isr(int32_t len)¶

Calling the esp_at_port_recv_data_notify_from_isr to notify at module that at port received data. When received this notice,at task will get data by calling get_data_length and read_data in esp_at_device_ops. This function MUST be used in isr.

Parameters

len: data length

bool esp_at_port_recv_data_notify(int32_t len, uint32_t msec)¶

Calling the esp_at_port_recv_data_notify to notify at module that at port received data. When received this notice,at task will get data by calling get_data_length and read_data in esp_at_device_ops. This function MUST NOT be used in isr.

Return

true : succeed
false : fail

Parameters

len: data length
msec: timeout time,The unit is millisecond. It waits forever,if msec is portMAX_DELAY.

void esp_at_transmit_terminal_from_isr(void)¶: terminal transparent transmit mode,This function MUST be used in isr.

void esp_at_transmit_terminal(void)¶: terminal transparent transmit mode,This function MUST NOT be used in isr.

bool esp_at_custom_cmd_array_regist(const esp_at_cmd_struct *custom_at_cmd_array, uint32_t cmd_num)¶

regist at command set, which defined by custom,

Parameters

custom_at_cmd_array: at command set
cmd_num: command number

void esp_at_device_ops_regist(esp_at_device_ops_struct *ops)¶

regist device operate functions set,

Parameters

ops: device operate functions set

bool esp_at_custom_net_ops_regist(int32_t link_id, esp_at_custom_net_ops_struct *ops)¶

bool esp_at_custom_ble_ops_regist(int32_t conn_index, esp_at_custom_ble_ops_struct *ops)¶

void esp_at_custom_ops_regist(esp_at_custom_ops_struct *ops)¶

regist custom operate functions set interacting with AT,

Parameters

ops: custom operate functions set

uint32_t esp_at_get_version(void)¶

get at module version number,

Return: at version bit31~bit24: at main version bit23~bit16: at sub version bit15~bit8 : at test version bit7~bit0 : at custom version

void esp_at_response_result(uint8_t result_code)¶

response AT process result,

Parameters

result_code: see esp_at_result_code_string_index

int32_t esp_at_port_write_data(uint8_t *data, int32_t len)¶

write data into device,

Return

>= 0 : the real length of the data written
others : fail.

Parameters

data: data buffer to be written
len: data length

int32_t esp_at_port_active_write_data(uint8_t *data, int32_t len)¶

call pre_active_write_data_callback() first and then write data into device,

Return

>= 0 : the real length of the data written
others : fail.

Parameters

data: data buffer to be written
len: data length

int32_t esp_at_port_read_data(uint8_t *data, int32_t len)¶

read data from device,

Return

>= 0 : the real length of the data read from device
others : fail

Parameters

data: data buffer
len: data length

bool esp_at_port_wait_write_complete(int32_t timeout_msec)¶

wait for transmitting data completely to peer device,

Return

true : succeed,transmit data completely
false : fail

Parameters

timeout_msec: timeout time,The unit is millisecond.

int32_t esp_at_port_get_data_length(void)¶

get the length of the data received,

Return

>= 0 : the length of the data received
others : fail

bool esp_at_base_cmd_regist(void)¶: regist at base command set. If not,you can not use AT base command

bool esp_at_user_cmd_regist(void)¶: regist at user command set. If not,you can not use AT user command

bool esp_at_wifi_cmd_regist(void)¶: regist at wifi command set. If not,you can not use AT wifi command

bool esp_at_net_cmd_regist(void)¶: regist at net command set. If not,you can not use AT net command

bool esp_at_mdns_cmd_regist(void)¶: regist at mdns command set. If not,you can not use AT mdns command

bool esp_at_driver_cmd_regist(void)¶: regist at driver command set. If not,you can not use AT driver command

bool esp_at_wps_cmd_regist(void)¶: regist at wps command set. If not,you can not use AT wps command

bool esp_at_smartconfig_cmd_regist(void)¶: regist at smartconfig command set. If not,you can not use AT smartconfig command

bool esp_at_ping_cmd_regist(void)¶: regist at ping command set. If not,you can not use AT ping command

bool esp_at_http_cmd_regist(void)¶: regist at http command set. If not,you can not use AT http command

bool esp_at_mqtt_cmd_regist(void)¶: regist at mqtt command set. If not,you can not use AT mqtt command

bool esp_at_ble_cmd_regist(void)¶: regist at ble command set. If not,you can not use AT ble command

bool esp_at_ble_hid_cmd_regist(void)¶: regist at ble hid command set. If not,you can not use AT ble hid command

bool esp_at_blufi_cmd_regist(void)¶: regist at blufi command set. If not,you can not use AT blufi command

bool esp_at_bt_cmd_regist(void)¶: regist at bt command set. If not,you can not use AT bt command

bool esp_at_bt_spp_cmd_regist(void)¶: regist at bt spp command set. If not,you can not use AT bt spp command

bool esp_at_bt_a2dp_cmd_regist(void)¶: regist at bt a2dp command set. If not,you can not use AT bt a2dp command

bool esp_at_fs_cmd_regist(void)¶: regist at fs command set. If not,you can not use AT fs command

bool esp_at_eap_cmd_regist(void)¶: regist at WPA2 Enterprise AP command set. If not,you can not use AT EAP command

bool esp_at_eth_cmd_regist(void)¶: regist at ethernet command set. If not,you can not use AT ethernet command

bool esp_at_custom_cmd_line_terminator_set(uint8_t *terminator)¶

Set AT command terminator, by default, the terminator is “\r\n” You can change it by calling this function, but it just supports one character now.

Return

true : succeed,transmit data completely
false : fail

Parameters

terminator: the line terminator

uint8_t *esp_at_custom_cmd_line_terminator_get(void)¶

Get AT command line terminator,by default, the return string is “\r\n”.

Return: the command line terminator

const esp_partition_t *esp_at_custom_partition_find(esp_partition_type_t type, esp_partition_subtype_t subtype, const char *label)¶

Find the partition which is defined in at_customize.csv.

Return

pointer to esp_partition_t structure, or NULL if no partition is found. This pointer is valid for the lifetime of the application

Parameters

type: the type of the partition
subtype: the subtype of the partition
label: Partition label

void esp_at_port_enter_specific(esp_at_port_specific_callback_t callback)¶

Set AT core as specific status, it will call callback if receiving data. for example:

static void wait_data_callback (void)
{
    xSemaphoreGive(sync_sema);
}

void process_task(void* para)
{
    vSemaphoreCreateBinary(sync_sema);
    xSemaphoreTake(sync_sema,portMAX_DELAY);
    esp_at_port_write_data((uint8_t *)">",strlen(">"));
    esp_at_port_enter_specific(wait_data_callback);
    while(xSemaphoreTake(sync_sema,portMAX_DELAY)) {
        len = esp_at_port_read_data(data, data_len);
        // TODO:
    }
}

Parameters

callback: which will be called when received data from AT port

void esp_at_port_exit_specific(void)¶: Exit AT core as specific status.

const uint8_t *esp_at_get_current_cmd_name(void)¶: Get current AT command name.

esp_err_t esp_at_wifi_event_handler(void *ctx, system_event_t *event)¶

Wi-Fi event handler callback, which used in AT core.

Return

ESP_OK: succeed
others: fail

Parameters

ctx: reserved for user
event: event type defined in this file

void at_handle_result_code(esp_at_result_code_string_index code, void *pbuf)¶

Structures¶

struct esp_at_cmd_struct¶

esp_at_cmd_struct used for define at command

Public Members

char *at_cmdName¶: at command name

uint8_t (*at_testCmd)(uint8_t *cmd_name)¶: Test Command function pointer

uint8_t (*at_queryCmd)(uint8_t *cmd_name)¶: Query Command function pointer

uint8_t (*at_setupCmd)(uint8_t para_num)¶: Setup Command function pointer

uint8_t (*at_exeCmd)(uint8_t *cmd_name)¶: Execute Command function pointer

struct esp_at_device_ops_struct¶

esp_at_device_ops_struct device operate functions struct for AT

Public Members

int32_t (*read_data)(uint8_t *data, int32_t len)¶: read data from device

int32_t (*write_data)(uint8_t *data, int32_t len)¶: write data into device

int32_t (*get_data_length)(void)¶: get the length of data received

bool (*wait_write_complete)(int32_t timeout_msec)¶: wait write finish

struct esp_at_custom_net_ops_struct¶

esp_at_custom_net_ops_struct custom socket callback for AT

Public Members

int32_t (*recv_data)(uint8_t *data, int32_t len)¶: callback when socket received data

void (*connect_cb)(void)¶: callback when socket connection is built

void (*disconnect_cb)(void)¶: callback when socket connection is disconnected

struct esp_at_custom_ble_ops_struct¶

esp_at_custom_ble_ops_struct custom ble callback for AT

Public Members

int32_t (*recv_data)(uint8_t *data, int32_t len)¶: callback when ble received data

void (*connect_cb)(void)¶: callback when ble connection is built

void (*disconnect_cb)(void)¶: callback when ble connection is disconnected

struct esp_at_custom_ops_struct¶

esp_at_ops_struct some custom function interacting with AT

Public Members

void (*status_callback)(esp_at_status_type status)¶: callback when AT status changes

void (*pre_sleep_callback)(at_sleep_mode_t mode)¶: callback before enter modem sleep and light sleep

void (*pre_deepsleep_callback)(void)¶: callback before enter deep sleep

void (*pre_restart_callback)(void)¶: callback before restart

void (*pre_active_write_data_callback)(at_write_data_fn_t)¶: callback before write data

Macros¶

at_min(x, y)¶

at_max(x, y)¶

ESP_AT_ERROR_NO(subcategory, extension)¶

ESP_AT_CMD_ERROR_OK¶: No Error

ESP_AT_CMD_ERROR_NON_FINISH¶: terminator character not found (“\r\n” expected)

ESP_AT_CMD_ERROR_NOT_FOUND_AT¶: Starting “AT” not found (or at, At or aT entered)

ESP_AT_CMD_ERROR_PARA_LENGTH(which_para)¶: parameter length mismatch

ESP_AT_CMD_ERROR_PARA_TYPE(which_para)¶: parameter type mismatch

ESP_AT_CMD_ERROR_PARA_NUM(need, given)¶: parameter number mismatch

ESP_AT_CMD_ERROR_PARA_INVALID(which_para)¶: the parameter is invalid

ESP_AT_CMD_ERROR_PARA_PARSE_FAIL(which_para)¶: parse parameter fail

ESP_AT_CMD_ERROR_CMD_UNSUPPORT¶: the command is not supported

ESP_AT_CMD_ERROR_CMD_EXEC_FAIL(result)¶: the command execution failed

ESP_AT_CMD_ERROR_CMD_PROCESSING¶: processing of previous command is in progress

ESP_AT_CMD_ERROR_CMD_OP_ERROR¶: the command operation type is error

Type Definitions¶

typedef int32_t (*at_write_data_fn_t)(uint8_t *data, int32_t len)¶

typedef void (*esp_at_port_specific_callback_t)(void)¶: AT specific callback type.

Enumerations¶

enum esp_at_status_type¶

esp_at_status some custom function interacting with AT

Values:

ESP_AT_STATUS_NORMAL = 0x0¶: Normal mode.Now mcu can send AT command

ESP_AT_STATUS_TRANSMIT¶: Transparent Transmition mode

enum at_sleep_mode_t¶

Values:

AT_DISABLE_SLEEP = 0¶

AT_MIN_MODEM_SLEEP¶

AT_LIGHT_SLEEP¶

AT_MAX_MODEM_SLEEP¶

AT_SLEEP_MAX¶

enum esp_at_module¶

module number,Now just AT module

Values:

ESP_AT_MODULE_NUM = 0x01¶: AT module

enum esp_at_error_code¶

subcategory number

Values:

ESP_AT_SUB_OK = 0x00¶: OK

ESP_AT_SUB_COMMON_ERROR = 0x01¶: reserved

ESP_AT_SUB_NO_TERMINATOR = 0x02¶: terminator character not found (“\r\n” expected)

ESP_AT_SUB_NO_AT = 0x03¶: Starting “AT” not found (or at, At or aT entered)

ESP_AT_SUB_PARA_LENGTH_MISMATCH = 0x04¶: parameter length mismatch

ESP_AT_SUB_PARA_TYPE_MISMATCH = 0x05¶: parameter type mismatch

ESP_AT_SUB_PARA_NUM_MISMATCH = 0x06¶: parameter number mismatch

ESP_AT_SUB_PARA_INVALID = 0x07¶: the parameter is invalid

ESP_AT_SUB_PARA_PARSE_FAIL = 0x08¶: parse parameter fail

ESP_AT_SUB_UNSUPPORT_CMD = 0x09¶: the command is not supported

ESP_AT_SUB_CMD_EXEC_FAIL = 0x0A¶: the command execution failed

ESP_AT_SUB_CMD_PROCESSING = 0x0B¶: processing of previous command is in progress

ESP_AT_SUB_CMD_OP_ERROR = 0x0C¶: the command operation type is error

enum esp_at_para_parse_result_type¶

the result of AT parse

Values:

ESP_AT_PARA_PARSE_RESULT_FAIL = -1¶: parse fail,Maybe the type of parameter is mismatched,or out of range

ESP_AT_PARA_PARSE_RESULT_OK = 0¶: Successful

ESP_AT_PARA_PARSE_RESULT_OMITTED¶: the parameter is OMITTED.

enum esp_at_result_code_string_index¶

the result code of AT command processing

Values:

ESP_AT_RESULT_CODE_OK = 0x00¶: “OK”

ESP_AT_RESULT_CODE_ERROR = 0x01¶: “ERROR”

ESP_AT_RESULT_CODE_FAIL = 0x02¶: “ERROR”

ESP_AT_RESULT_CODE_SEND_OK = 0x03¶: “SEND OK”

ESP_AT_RESULT_CODE_SEND_FAIL = 0x04¶: “SEND FAIL”

ESP_AT_RESULT_CODE_IGNORE = 0x05¶: response nothing, just change internal status

ESP_AT_RESULT_CODE_PROCESS_DONE = 0x06¶: response nothing, just change internal status

ESP_AT_RESULT_CODE_OK_AND_INPUT_PROMPT = 0x07¶: response nothing, just change internal status

ESP_AT_RESULT_CODE_MAX¶

Header File¶

at/include/esp_at.h

Functions¶

const char *esp_at_get_current_module_name(void)¶: get current module name

const char *esp_at_get_module_name_by_id(uint32_t id)¶: get module name by index

uint32_t esp_at_get_module_id(void)¶: get current module id

void esp_at_board_init(void)¶: init peripheral and default parameters in factory_param.bin

bool esp_at_web_server_cmd_regist(void)¶: regist WiFi config via web command. If not,you can not use web server to config wifi connect

Macros¶

ESP_AT_PORT_TX_WAIT_MS_MAX¶

ESP_AT_FACTORY_PARAMETER_SIZE¶

Customized AT Commands and Firmware¶

Tencent Cloud IoT AT Commands and Firmware¶

Tencent Cloud IoT AT Command Set¶

Please refer to [Chinese version]. The English version is not provided since the firmware and commands are applicable to the Chinese market (Tencent).

Tencent Cloud IoT AT Firmware¶

ESP8266¶

ESP8266-WROOM-02 Series

QCloud_AT_ESP8266_v2.2.0

QCloud_AT_ESP8266_v2.1.1

Index of Abbreviations¶

A2DP

Advanced Audio Distribution Profile

高级音频分发框架

ADC

Analog-to-Digital Converter

模拟数字转换器

ALPN

Application Layer Protocol Negotiation

应用层协议协商

AT port

AT port is the general name of AT log port (that is used to output log) and AT command port (that is used to send AT commands and receive responses). Please refer to Hardware Connection for default AT port pins and How to Set AT Port Pins for how to customize them.

AT 端口是 AT 日志端口（用于输出日志）和 AT 命令端口（用于发送 AT 命令和接收响应）的总称。请参考 Hardware Connection 了解默认的 AT 端口管脚，参考 How to Set AT Port Pins 了解如何自定义 AT 端口管脚。

Bluetooth LE

Bluetooth Low Energy

低功耗蓝牙

BluFi

Wi-Fi network configuration function via Bluetooth channel

BluFi 是一款基于蓝牙通道的 Wi-Fi 网络配置功能

DHCP

Dynamic Host Configuration Protocol

动态主机配置协议

DNS

Domain Name System

域名系统

DTIM

Delivery Traffic Indication Map

延迟传输指示映射

GATTC

Generic Attributes client

GATT 客户端

GATTS

Generic Attributes server

GATT 服务器

HID

Human Interface Device

人机接口设备

I2C

Inter-Integrated Circuit

集成电路总线

ICMP

Intemet Control Message Protocol

因特网控制报文协议

LWT

Last Will and Testament

遗嘱

MAC

Media Access Control

MAC 地址

mDNS

Multicast Domain Name System

多播 DNS

MSB

Most Significant Bit

最高有效位

MTU

maximum transmission unit

最大传输单元

NVS

Non-Volatile Storage

非易失性存储器

Normal Transmission Mode

Default Transmission Mode

In normal transmission mode, users can send AT commands. For examples, users can send MCU data received by AT command port to the opposite end of transmission by AT+CIPSEND; and the data received from the opposite end of transmission will also be returned to MCU through AT command port with additional prompt: +IPD.

During a normal transmission, if the connection breaks, ESP devices will give a prompt and will not attempt to reconnect.

More details are in Transmission Mode Shift Diagram.

普通传输模式

默认传输模式

在普通传输模式下，用户可以发送 AT 命令。例如，用户可以通过 AT+CIPSEND 命令，发送 AT 命令口收到的 MCU 数据到传输对端。从传输对端收到的数据，会通过 AT 命令口返回给 MCU，同时会附带 +IPD 信息。

普通传输模式时，如果连接断开，ESP 不会重连，并提示连接断开。

更多介绍请参考 Transmission Mode Shift Diagram。

Passthrough Mode

Also called as “Passthrough Sending & Receiving Mode”.

In passthrough mode, users cannot send AT commands except special +++ command. All MCU data received by AT command port will be sent to the opposite end of transmission without any modification; and the data received from the opposite end of transmission will also be returned to MCU through AT command port without any modification.

During the Wi-Fi passthrough transmission, if the connection breaks, ESP devices will keep trying to reconnect until +++ is input to exit the passthrough transmission.

More details are in Transmission Mode Shift Diagram.

透传模式

也称为 “透传发送接收模式”。

在透传模式下，用户不能发送其它 AT 命令，除了特别的 +++ 命令。AT 命令口收到的所有的 MCU 数据都将无修改地，发送到传输对端。从传输对端收到的数据也会通过 AT 命令口无修改地，返回给 MCU。

Wi-Fi 透传模式传输时，如果连接断开，ESP 会不停地尝试重连，此时单独输入 +++ 退出透传，则停止重连。

更多介绍请参考 Transmission Mode Shift Diagram。

Transmission Mode Shift Diagram

More details are in the following introduction.

Normal Transmission Mode (普通传输模式)
Passthrough Receiving Mode (透传接收模式)
Passthrough Mode (透传模式)
AT+CIPMODE
AT+CIPSEND
+++
AT+SAVETRANSLINK

Passthrough Receiving Mode

The temporary mode between Normal Transmission Mode and Passthrough Mode.

In passthrough receiving mode, AT cannot send any data to the opposite end of transmission; but the data received from the opposite end of transmission can be returned to MCU through AT command port without any modification. More details are in Transmission Mode Shift Diagram.

透传接收模式

在普通传输模式和透传模式之间的一个临时模式。

在透传接收模式，AT 不能发送数据到传输对端；但 AT 可以收到来自传输对端的数据，通过 AT 命令口无修改地返回给 MCU。更多介绍请参考 Transmission Mode Shift Diagram。

PBC

Push Button Configuration

按钮配置

PCI Authentication

Payment Card Industry Authentication. In ESP-AT project, it refers to all Wi-Fi authentication modes except OPEN and WEP.

PCI 认证，在 ESP-AT 工程中指的是除 OPEN 和 WEP 以外的 Wi-Fi 认证模式。

PLCP

Physical Layer Convergence Procedure

PLCP 协议，即物理层会聚协议

PMF

protected management frame

受保护的管理帧

PSK

Pre-shared Key

预共享密钥

PWM

Pulse-Width Modulation

脉冲宽度调制

QoS

Quality of Service

服务质量

RTC

Real Time Controller. A group of circuits in SoC that keeps working in any chip mode and at any time.

实时控制器，为 SoC 中的一组电路，在任何芯片模式下都能随时保持工作。

SMP

Security Manager Protocol

安全管理协议

SNI

Server Name Indication

服务器名称指示

SNTP

Simple Network Time Protocol

简单网络时间协议

SPI

Serial Peripheral Interface

串行外设接口

SPP

Serial Port Profile

SPP 协议，即串口协议

SSL

Secure Sockets Layer

SSL 协议，即安全套接字协议

TLS

Transport Layer Security

TLS 协议，即传输层安全性协议

URC

Unsolicited Result Code

非请求结果码，一般为模组给 MCU 的串口返回

UTC

Coordinated Universal Time

协调世界时

UUID

universally unique identifier

通用唯一识别码

WEP

Wired-Equivalent Privacy

WEP 加密方式，即有线等效加密

WPA

Wi-Fi Protected Access

Wi-Fi 保护访问

WPA2

Wi-Fi Protected Access II

Wi-Fi 保护访问 II

WPS

Wi-Fi Protected Setup

Wi-Fi 保护设置

Index

Provide feedback about this document

set value	actual value	actual dBm
[34,43]	34	8.5
[44,51]	44	11
[52,55]	52	13
[56,59]	56	14
[60,65]	60	15
[66,71]	66	16.5
[72,77]	72	18
78	78	19.5

set value	actual value	actual dBm
[40,47]	32	8
[48,55]	48	12
[56,63]	56	14
[64,67]	64	16
[68,73]	68	17
[74,77]	74	18.5
[78,81]	78	19.5
82	82	20.5

ESP-AT User Guide¶

Get Started¶

What is ESP-AT¶

Hardware Connection¶

What You Need¶

ESP32 Series¶

ESP32-WROOM-32 Series¶

ESP32-WROVER Series¶

ESP32-PICO Series¶

ESP32-SOLO Series¶

ESP32-S2 Series¶

ESP32-C3 Series¶

ESP8266 Series¶

Downloading Guide¶

Download AT Firmware¶

Flash AT Firmware into Your Device¶

Windows¶

Linux or macOS¶

Check Whether AT Works¶

AT Binary Lists¶

Released Firmware¶

ESP32-WROOM-32 Series¶

ESP32-WROVER-32 Series¶

ESP32-PICO Series¶

ESP32-SOLO Series¶

Released Firmware¶

ESP32-S2-WROOM Series¶

ESP32-S2-WROVER Series¶

ESP32-S2-SOLO Series¶

ESP32-S2-MINI Series¶

Released Firmware¶

ESP-WROOM-02 Series¶

AT Command Set¶

Basic AT Commands¶

AT: Test AT Startup¶

Execute Command¶

AT+RST: Restart a Module¶

Execute Command¶

AT+GMR: Check Version Information¶

Execute Command¶

Parameters¶

Note¶

Example¶

AT+CMD: List all AT commands and types supported in current firmware¶

Query Command¶

Parameters¶

AT+GSLP: Enter Deep-sleep Mode¶

Set Command¶

Parameter¶

Notes¶

ATE: Configure AT Commands Echoing¶

Execute Command¶

Parameters¶

AT+RESTORE: Restore Factory Default Settings¶

Execute Command¶

Notes¶

AT+UART_CUR: Current UART Configuration, Not Saved in Flash¶

Query Command¶

Set Command¶

Parameters¶

Notes¶

Example¶

AT+UART_DEF: Default UART Configuration, Saved in Flash¶

Query Command¶

Set Command¶

Parameters¶

Notes¶

Example¶

AT+SLEEP: Set the Sleep Mode¶

Query Command¶

Set Command¶

Parameter¶

Note¶

Example¶

AT+SYSRAM: Query Current Remaining Heap Size and Minimum Heap Size¶

Query Command¶

Parameters¶

Example¶

AT+SYSMSG: Query/Set System Prompt Information¶

Query Command¶