by ober » Mon Mar 15, 2010 12:39 pm
Try to understand the operation of GSM modem that you have, using computer. Since computer have the software (HyperTerminal) and straight forward input (keyboard), you can easily see the feedback from GSM modem and input command.
If you are familiar with the operation, develop the software to communicate with GSM modem on your microcontroller. Hardware come first, you will need to ensure serial communication is ready from microcontroller to GSM modem, will need to take UART to RS232.
Sound easy, but is very challenging, so good luck and share your progress with us.