The given code covers all the basic needs to communicate with A7672s SIMCom Module with ESP32 to post data on MQTT

I am using ESP32 Devkit V1

• GPIO 2 : Builtin LED ( Devkit V1 )
• GPIO 17 : UART TX
• GPIO 16 : UART RX
• GPIO 21 : ENABLE of A7672s

• This code is developed for ESP32 on Embedded C Language using FreeRTOS.
• Entire Communication is based on UART protocol between ESP and A7672s SIMCom.
• The default baud of SIMCom is 115200 with 8 data bits, None parity and 1 stop bit.
• There are several "AT" Commands over which SIMCom understands, performance and responses tasks.
• The code initializes AT Commands, followed by getting the IP of simcard used.
• Further, through SNTP we get the date-time for specified location.
• Lastly, MQTT is started with specified broker and payload is posted on "4GBOARD_SIMCOMM".
• We also subscribe to a topic "4GBOARD_SIMCOMM/cmd" to receive payload.
• Note :
• 1) Simcard used need to have whitelisting of SNTP or broker being used ( if simcard is not general one ).
• 2) If SIMCom loses given MQTT Connection, then it would disconnect and stop MQTT by executing those AT Commands before restarting.

• There is nothing to conclude this time, it's super cool and works flawlessly.
• I have used basic AT Commands to perform few task but there's a big list of things one can discover and do!
• I hope you all like it :-D

• https://microchip.ua/simcom/LTE/A76xx/A7682/A76XX%20Series_AT_Command_Manual_V1.06.pdf
• https://manuals.plus/m/d70efb93e7bade7e6e61c78447a99e33b2f6607d08d3fa59b8ac5c65f8bb201d.pdf
• https://m5stack.oss-cn-shenzhen.aliyuncs.com/resource/docs/datasheet/module/sim7680/A76XX%20Series_UART_Application%20Note_V1.02.pdf