Sending and Receiving SMS with a SIM800 GSM Module - Tutorial (#124)

The SIM800 is a low cost SMS module that you can use in electronic/IoT projects. It does have a few quirks, though. I set one up here and show how to send and receive text messages. See also: Tutorial on the SIM900 modue:    • Sending and Receiving SMS with a SIM900 GS...   Tutorial on the M590 module:    • Sending and Receiving SMS with a M590E GSM...   My github site: https://github.com/magiccow/sim900 AT command reference for the SIM800: https://www.elecrow.com/wiki/images/2...