Dwi259eti Firmware Guide

// registration – called from at_init() void at_register_my_feature(void)

// read 2‑byte temperature cmd = i2c_cmd_link_create(); i2c_master_start(cmd); i2c_master_write_byte(cmd, (0x48 << 1) Keeping the sensor‑reading code isolated makes unit‑testing easier and prevents the AT parser from becoming a monolith. 4.3 Glue Layer – AT Command (if applicable) // at_cmd_myfeat.c #include "at.h" #include "my_feature.h"

Write this spec in a short markdown file ( FEATURE_SPEC.md ). It will be your contract with the code. Below is a generic flow; adapt the file names and APIs to the DWI259ETI SDK you have. 4.1 Add New Source Files (or extend existing ones) src/ ├─ feature/ │ ├─ my_feature.c // core logic │ └─ my_feature.h └─ at/ └─ at_cmd_myfeat.c // AT parser glue (if needed) 4.2 Core Logic ( my_feature.c ) #include "my_feature.h" #include "driver/gpio.h" #include "driver/i2c.h" #include "nvs.h" #include "esp_log.h" Dwi259eti Firmware

Add the registration call in the AT subsystem init routine (often at_init.c ). If the feature needs user‑configurable thresholds:

nvs_handle_t h; ESP_ERROR_CHECK(nvs_open("my_feat", NVS_READWRITE, &h)); ESP_ERROR_CHECK(nvs_set_blob(h, "threshold", &thr, sizeof(thr))); ESP_ERROR_CHECK(nvs_commit(h)); nvs_close(h); return ESP_OK; Below is a generic flow; adapt the file

void my_feature_task(void *arg)

float temperature; if (my_feature_get_temperature(&temperature) == 0) at_reply("%0.2f", temperature); else at_reply_error(); Below is a generic flow

If the feature is periodic, spawn a FreeRTOS task: