How to add user-defined AT commands

AT firmware is based on the Espressif IoT Development Framework (ESP-IDF). Espressif Systems’ AT commands are provided in libat_core.a, which is included in the AT BIN firmware.

Examples of implementing user-defined AT commands are provided in main/interface/uart/at_uart_task.c.

• The total length of an AT command cannot be longer than 256 bytes.
• Only alphabetic characters (A~Z, a~z), numeric characters (0~9), and some other characters (!, %, -, ., /, :, _) are supported when naming user-defined AT commands.
• The structure, esp_at_cmd_struct, is used to define four types of a command.