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
For information about the AT commands supported by your GSM modem and how to use them you will, obviously, have to read the Manual for your particular make and model of modem.
See: www.8052.com/.../160143
As far as the GSM modem is concerned, it is entirely irrelevant that the commands are being sent by a microcontroller.
As far as the microcontroller is concerned, it is simply a matter of sending and recieving serial data - the fact that it's a GSM modem is entirely irrelevant.
how then do you think i should go about it, since it is the microcontroller that will feed the gsm module
How would you go about it if you want your microcontroller to use its serial port to send GSM commands to _you_. No much difference from sending "hello world" messages to you. Then only addition is that "hello world" is one-direction while the GSM module needs two-way communication.
Any sample code you can find that implements a menu system will contain both output and input for the serial port.
Don't invent problems where no problems exists. Instead, concentrate on exactly how you use a terminal program on your PC to send data to the GSM module, and to wait for information back.
You should follow the procedure given earlier: www.8052.com/.../160143
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.