Good day! I have Arduino uno and GSM Module. I have attached legs to GSM Shield and put them together like sandwich, but I can’t get correct responce in Port Monitor when I use AT commands, what code I need to use to make it works?
Where did you buy the GSM shield?
Have you checked your soldering on the headers?
Ebay, soldering is ok.
Put the two jumpers near the antenna connection to D7 & D8. Use SerialRelay in the link in my signature to send commands.
I don't know if that shield has software power control, but you always try it and see.