Unable to connect 900a GSM module with PIC micro controller
Hello Guys,
I purchase a GSM SIM900a modem. I connected it to PC using RS232 port and able to give command to GSM modem via PC and GSM modem sending message as expected.
When I try to fire same set of commands to GSM modem via PIC microcontroller. No message is getting sent to outside world.
1. I have checked RX, TX pin connection. (CROSSED connection with GSM modem).
2. GND is also common.
Could you please suggest, How can I troubleshoot whats going wrong?