Extracting response from TC35i GSM using PIC16f690

Discussion in 'The Projects Forum' started by White Coral, May 4, 2011.

  1. White Coral

    Thread Starter New Member

    May 4, 2011
    Hi all,

    I am now trying to extract the response from TC35i GSM using pic16f690. When I send "AT" to GSM, the GSM suppose to give me an "OK" response. However, the PIC16f690 cannot receive the response properly. I actually use MAX232 to connect GSM with PIC and I use another MAX232 to connect PIC with Hyperterminal. From Hyperterminal I can see the received response from the GSM. From the result, I know that instead of receiving only an "OK", the PIC will also receive the echo of "AT". Below is my code,

    for(j=0; j<2; j++)
    TXREG=C[j]; // Sending "AT"
    for(i=0; i<500; i++) // Delay

    TXREG = 0x0D; // Sending "Enter"

    if (RCREG=='T') // If receive "T"
    PORTC = 0x01; // LED will turn on

    Even if i try with RCREG=='O' or RCREG=='K', the LED will not turn on. How to make PIC16f690 be able to read the response from GSM correctly?

    I need your help earnestly. I will truly appreciate any help from you guys. Thank you so much.