I am looking for some code to connect SIM800 ( or similar ) GSM module to ESP8266 as alternative
WWW connection in case WiFI not present . There is lost of Arduino based code for this purpose but I am running Espressif SDK on ESP . I have implemented softuart code for creating serial Uart connection to SIM800
and carried over some Arduino drivers for SIM800 . But I am looking for native SDK source code for AT command communication with these GSM modules ( SIM800 or similar ) .
Thanks for info .