pls, i need help. i am currently writing a project using interactive voice response system and i need to interface a gsm modem to a microcontroller using AT commands. anyone with useful info should pls send me help. thanks
You have to use AT commands for interfacing with GSM modem,for that u have to read AT command manual.and modem should interface on UART. after sending command to modem you can observe responce of modem on hyperterminal,If u getting OK then after sucessful communication.and gives ERROR when fails to communate.
"If u getting OK then after sucessful communication. and gives ERROR when fails to communicate."
Remember that there are (at least) two types of "communication" going on here:
1. The "local" communication between the terminal (or microcontroller) and the modem itself;
2. The "remote" communication between the terminal and the remote host - which just goes through the modem.
The OK and ERROR responses are usually part of the "local" communication between the terminal (or microcontroller) and the modem itself.