ESP32-PICO-KIT V4 / V4.1 Getting Started Guide¶
This guide shows how to get started with the ESP32-PICO-KIT V4 / V4.1 mini development board. For the description of other ESP32-PICO-KIT versions, please check ESP32 Hardware Reference.
This particular description covers ESP32-PICO-KIT V4 and V4.1. The difference is the upgraded USB-UART bridge from CP2102 in V4 with up to 1 Mbps transfer rates to CP2102N in V4.1 with up to 3 Mbps transfer rates.
What You Need¶
- ESP32-PICO-KIT mini development board
- USB 2.0 A to Micro B cable
- Computer running Windows, Linux, or macOS
You can skip the introduction sections and go directly to Section Start Application Development.
ESP32-PICO-KIT is an ESP32-based mini development board produced by Espressif.
The core of this board is ESP32-PICO-D4 - a System-in-Package (SiP) module with complete Wi-Fi and Bluetooth functionalities. Compared to other ESP32 modules, ESP32-PICO-D4 integrates the following peripheral components in one single package, which otherwise would need to be installed separately:
- 40 MHz crystal oscillator
- 4 MB flash
- Filter capacitors
- RF matching links
This setup reduces the costs of additional external components as well as the cost of assembly and testing and also increases the overall usability of the product.
The development board features a USB-UART Bridge circuit which allows developers to connect the board to a computer’s USB port for flashing and debugging.
All the IO signals and system power on ESP32-PICO-D4 are led out to two rows of 20 x 0.1” header pads on both sides of the development board for easy access. For compatibility with Dupont wires, 2 x 17 header pads are populated with two rows of male pin headers. The remaining 2 x 3 header pads beside the antenna are not populated. These pads may be populated later by the user if required.
- The 2 x 3 pads not populated with pin headers are connected to the flash memory embedded in the ESP32-PICO-D4 SiP module. For more details see module’s datasheet in Related Documents.
- ESP32-PICO-KIT comes with male headers by default.
The block diagram below shows the main components of ESP32-PICO-KIT and their interconnections.
The following figure and the table below describe the key components, interfaces, and controls of the ESP32-PICO-KIT board.
Below is the description of the items identified in the figure starting from the top left corner and going clockwise.
|ESP32-PICO-D4||Standard ESP32-PICO-D4 module soldered to the ESP32-PICO-KIT board. The complete ESP32 system on a chip (ESP32 SoC) has been integrated into the SiP module, requiring only an external antenna with LC matching network, decoupling capacitors, and a pull-up resistor for EN signals to function properly.|
|LDO||5V-to-3.3V Low dropout voltage regulator (LDO).|
|USB-UART bridge||Single-chip USB-UART bridge: CP2102 in V4 provides up to 1 Mbps transfer rates and CP2102N in V4.1 offers up to 3 Mbps transfers rates.|
|Micro USB Port||USB interface. Power supply for the board as well as the communication interface between a computer and the board.|
|5V Power On LED||This red LED turns on when power is supplied to the board. For details, see the schematics in Related Documents.|
|I/O||All the pins on ESP32-PICO-D4 are broken out to pin headers. You can program ESP32 to enable multiple functions, such as PWM, ADC, DAC, I2C, I2S, SPI, etc. For details, please see Section Pin Descriptions.|
|BOOT Button||Download button. Holding down Boot and then pressing EN initiates Firmware Download mode for downloading firmware through the serial port.|
|EN Button||Reset button.|
Power Supply Options¶
There are three mutually exclusive ways to provide power to the board:
- Micro USB port, default power supply
- 5V / GND header pins
- 3V3 / GND header pins
The power supply must be provided using one and only one of the options above, otherwise the board and/or the power supply source can be damaged.
The two tables below provide the Name and Function of I/O header pins on both sides of the board, see ESP32-PICO-KIT board layout. The pin numbering and header names are the same as in the schematic given in Related Documents.
GPIO8, SD_DATA1, SPID, HS1_DATA1 (See 1) , U2CTS
GPIO7, SD_DATA0, SPIQ, HS1_DATA0 (See 1) , U2RTS
GPIO6, SD_CLK, SPICLK, HS1_CLK (See 1) , U1CTS
GPIO21, VSPIHD, EMAC_TX_EN
GPIO22, VSPIWP, U0RTS, EMAC_TXD1
GPIO19, VSPIQ, U0CTS, EMAC_TXD0
GPIO23, VSPID, HS1_STROBE
GPIO18, VSPICLK, HS1_DATA7
GPIO5, VSPICS0, HS1_DATA6, EMAC_RX_CLK
GPIO10, SD_DATA3, SPIWP, HS1_DATA3, U1TXD
GPIO9, SD_DATA2, SPIHD, HS1_DATA2, U1RXD
GPIO3, U0RXD (See 3) , CLK_OUT2
GPIO1, U0TXD (See 3) , CLK_OUT3, EMAC_RXD2
GPIO38, ADC1_CH2, RTC_GPIO2
GPIO37, ADC1_CH1, RTC_GPIO1
3.3V power supply
GPIO16, HS1_DATA4 (See 1) , U2RXD, EMAC_CLK_OUT
GPIO17, HS1_DATA5 (See 1) , U2TXD, EMAC_CLK_OUT_180
GPIO11, SD_CMD, SPICS0, HS1_CMD (See 1) , U1RTS
GPIO36, ADC1_CH0, RTC_GPIO0
GPIO39, ADC1_CH3, RTC_GPIO3
GPIO25, DAC_1, ADC2_CH8, RTC_GPIO6, EMAC_RXD0
GPIO26, DAC_2, ADC2_CH9, RTC_GPIO7, EMAC_RXD1
32K_XP (See 2a) , ADC1_CH4, TOUCH9, RTC_GPIO9
32K_XN (See 2b) , ADC1_CH5, TOUCH8, RTC_GPIO8
GPIO27, ADC2_CH7, TOUCH7, RTC_GPIO17
ADC2_CH6, TOUCH6, RTC_GPIO16, MTMS, HSPICLK,
HS2_CLK, SD_CLK, EMAC_TXD2
ADC2_CH5, TOUCH5, RTC_GPIO15, MTDI (See 4) , HSPIQ,
HS2_DATA2, SD_DATA2, EMAC_TXD3
ADC2_CH4, TOUCH4, RTC_GPIO14, MTCK, HSPID,
HS2_DATA3, SD_DATA3, EMAC_RX_ER
ADC2_CH3, TOUCH3, RTC_GPIO13, MTDO, HSPICS0
HS2_CMD, SD_CMD, EMAC_RXD3
ADC2_CH2, TOUCH2, RTC_GPIO12, HSPIWP,
ADC2_CH0, TOUCH0, RTC_GPIO10, HSPIHD,
HS2_DATA1, SD_DATA1, EMAC_TX_ER
ADC2_CH1, TOUCH1, RTC_GPIO11, CLK_OUT1
3.3V power supply
5V power supply
The following notes give more information about the items in the tables above.
- This pin is connected to the flash pin of ESP32-PICO-D4.
- 32.768 kHz crystal oscillator: a) input b) output
- This pin is connected to the pin of the USB bridge chip on the board.
- The operating voltage of ESP32-PICO-KIT’s embedded SPI flash is 3.3V. Therefore, the strapping pin MTDI should hold bit zero during the module power-on reset. If connected, please make sure that this pin is not held up on reset.
Start Application Development¶
Before powering up your ESP32-PICO-KIT, please make sure that the board is in good condition with no obvious signs of damage.
The dimensions are 52 x 20.3 x 10 mm (2.1” x 0.8” x 0.4”).
For the board physical construction details, please refer to its Reference Design listed below.