SIM800L is a minuscule GSM module that offers 2G GSM/GPRS data, and supports SIMCOM enhanced AT commands. Because it uses the serial ... to interface with a microcontroller like the venerable Arduino!

It is very easy to build an “SMS-controlled relay” with the help of a cheap GSM modem module and a small microcontroller board. Here, I’m using the SIM800L and Arduino Nano V3 to develop a nifty ...