Hi everyone,
This page of the forum helped me a lot. I also have arduino mega 2560 and GSM SIM 900. I could see HELLO WORLD using your code on serial terminal. But i am not getting
+CFUN: 1
+CPIN: READY
Call Ready
on the serial terminal
I saw the pin mapping given by solanoan but i am confused with it. Can u elaborate about the pin connection between arduino and modem? Please reply as soon as possible.