Sim 900a Interfacing with AVR

@ExperimenterUK

Sir i'm not able to understand your first question.

Yes sir im able to send the sms through mobile phone.

I'm using a 12V adapter with 2A current capacity.

whats the PC software that you're using?

@AjayBhargav

I'm using Terminal v1.90b software sir.

@Ajaybhargav

Sir im using PL2303 USB-Serial converter with the gsm module. I also tried with rs-232 cable connected to my serial port but the result is same. Please need help its my project work. I just need to send the sms tats all. Previously i have done this but now i dont know why its not working :(

I am not sure if terminal software sends special key combinations. Please try to use a different software like TeraTerm and see if things work for you.