How to Add Support for a Module

[中文]

The ESP-AT project supports multiple modules, and provides configuration for them in the factory_param_data.csv table and the files in the module_config folder. See the table below for the supported platforms (chip series) and modules, as well as locations of the default configuration files.

default configuration files

Platform

Module

Default

ESP32

  • WROOM-32

  • PICO-D4

  • SOLO-1

  • MINI-1

ESP32

WROVER-32

ESP32

ESP32-D2WD

ESP32-C2

ESP32C2-2MB (all ESP32-C2 (ESP8684) series with 2 MB flash)

ESP32-C2

ESP32C2-4MB (all ESP32-C2 (ESP8684) series with 4 MB flash)

ESP32-C3

MINI-1

ESP32-C6

ESP32C6-4MB (all ESP32-C6 series with 4 MB flash)

Note

  • When the silence mode in ./build.py menuconfig is 0, the default sdkconfig corresponding to the module is sdkconfig.defaults.

  • When the silence mode in ./build.py menuconfig is 1, the default sdkconfig corresponding to the module is sdkconfig_silence.defaults.

If you want to add support for an ESP32-C6 module in your ESP-AT project, you need to modify those configuration files. The “ESP32-C6 module” here means:

  • Modules that the ESP-AT project has not supported yet, including those of supported platform and not supported platform. However, adding support for the latter requires extra huge work, thus not recommended and not explained in this document.

  • Modules that the ESP-AT project supports, but you want to modify the default configuration.

The document uses an example to explain how to add support for an ESP32-C6 module in the ESP-AT project. The example module is ESP32-WROOM-32 that uses SDIO instead of the default UART interface.

Add Module to factory_param_data.csv

Open your local factory_param_data.csv , insert a new row at the end, set the parameters as needed. In the example, we set platform to PLATFORM_ESP32, module_name to WROOM32-SDIO, as well as other parameters as follows (see Factory Parameter Configuration for what each parameter represents):

  • platform: PLATFORM_ESP32

  • module_name: WROOM32-SDIO

  • description:

  • version: 4

  • max_tx_power: 78

  • uart_port: 1

  • start_channel: 1

  • channel_num: 13

  • country_code: CN

  • uart_baudrate: -1

  • uart_tx_pin: -1

  • uart_rx_pin: -1

  • uart_cts_pin: -1

  • uart_rts_pin: -1

Modify esp_at_module_info Structure

Add customized module information in the esp_at_module_info structure in at/src/at_default_config.c.

The esp_at_module_info structure provides OTA upgrade verification token:

typedef struct {
    char* module_name;
    char* ota_token;
    char* ota_ssl_token;
} esp_at_module_info_t;

If you do not want to use OTA features, member 2 ota_token and member 3 ota_ssl_token should be set to NULL. Member 1 module_name must correspond to the field module_name in the factory_param_data.csv file.

The modified esp_at_module_info structure is as follows:

static const esp_at_module_info_t esp_at_module_info[] = {
#if defined(CONFIG_IDF_TARGET_ESP32)
  ...
#endif

#if defined(CONFIG_IDF_TARGET_ESP32C3)
  ...
#endif

#if defined(CONFIG_IDF_TARGET_ESP32C2)
  ...
#endif

#if defined(CONFIG_IDF_TARGET_ESP32C6)
  ...
#endif

#if defined(CONFIG_IDF_TARGET_ESP32C6)
  {"MY_MODULE",       CONFIG_ESP_AT_OTA_TOKEN_MY_MODULE,      CONFIG_ESP_AT_OTA_SSL_TOKEN_MY_MODULE },     // MY_MODULE
#endif
};

Macro CONFIG_ESP_AT_OTA_TOKEN_MY_MODULE and macro CONFIG_ESP_AT_OTA_SSL_TOKEN_MY_MODULE are defined in the header file at/private_include/at_ota_token.h.

#if defined(CONFIG_IDF_TARGET_ESP32C6)
...
#define CONFIG_ESP_AT_OTA_TOKEN_MY_MODULE       CONFIG_ESP_AT_OTA_TOKEN_DEFAULT

...
#define CONFIG_ESP_AT_OTA_SSL_TOKEN_MY_MODULE       CONFIG_ESP_AT_OTA_SSL_TOKEN_DEFAULT

Configure the Module

Firstly, enter module_config folder, and create a new folder to store all the configuration files for your module. Note that the folder name should be in lower case. Then, add the configuration files in the new folder: IDF_VERSION, at_customize.csv, partitions_at.csv, sdkconfig.defaults, and sdkconfig_silence.defaults.

In this example, we copy the module_esp32_default folder as well as the files within it and rename it as module_wroom32-sdio. The copied IDF_VERSION, at_customize.csv, and partitions_at.csv do not need any modification in our case. We only need to modify the sdkconfig.defaults and sdkconfig_silence.defaults:

  • Modify the two files to use the partition table in the module_wroom32-sdio folder as follows:

    CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="module_config/module_wroom32-sdio/partitions_at.csv"
CONFIG_PARTITION_TABLE_FILENAME="module_config/module_wroom32-sdio/partitions_at.csv"
CONFIG_AT_CUSTOMIZED_PARTITION_TABLE_FILE="module_config/module_wroom32-sdio/at_customize.csv"

  • Modify the two files to use the SDIO configuration and remove the UART configuration as follows:

    • Remove the UART configuration

      CONFIG_AT_BASE_ON_UART=n

    • Add the SDIO configuration

      CONFIG_AT_BASE_ON_SDIO=y

After finishing the above steps, you can recompile the ESP-AT project to generate the firmware for your module. In this example, we choose PLATFORM_ESP32 and WROOM32-SDIO when configuring the project to generate the firmware for it.

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