Problem interfacing LPC2148 with GSM

Hi.. I've written the following code for sending an SMS via the GSM module..
The code runs fine i.e. the entire code executes when the GSM is not connected to the LPC2148 board. This I can tell because I've inserted statements in the code to light LEDs so that I know till where the code has executed.

But, however, when I connect the GSM module to the board, code execution stops at the point indicated in the following code. It does not proceed further.

I've tried and tried but really cannot figure out why this is happening. Someone pls shed some light on this mystery. This is an important part of my college project.

what is the response for at from modem?

on hyperterminal it replied OK

I'm using SIM300 by the way.. Is that the problem?

Twisted_transistor said:

I'm using SIM300 by the way.. Is that the problem?

Click to expand...

try reading responses in hex format ,then you could find out the problem...sim300 is a simple to configure type modem..i have used it in many projects....

hey.. thanks.. The problem was that I was not handling the interrupts caused by the GSM module..
Do you know how to handle the interrupts?
It would really be helpful..

use the following code


#include<lpc214x.h>
#include"Config.h"

#define SW1 (IO0PIN & 0x00001000)
#define SW2 (IO0PIN & 0x00002000)
#define SW3 (IO0PIN & 0x00008000) //Macro Functions to read Push button switches on LPC2148 dev. board
#define SW4 (IO0PIN & 0x40000000)

void enter(void);

void GSM_init(void) ;

void send_sms1(void);
void send_sms2(void);
void send_sms3(void);
void send_sms4(void);

#define BUZZER_ON() IO0CLR=(1<<11) //Macro Functions to turn ON Buzzer

#define BUZZER_OFF() IO0SET=(1<<11) //Macro Functions to turn OFF Buzzer

int main()
{
PINSEL0 = 0x00050005; // Enable UART0 and UART1 Rx and Tx pins
PINSEL1 = 0x00000000;
PINSEL2 = 0x00000000;

IODIR0= (1<<11) ;
IODIR0=(0<<12)|(0<<13)|(0<<15)|(0<<30);
BUZZER_OFF();

lcd_init();
UART1_init();

GSM_init();

lcd_cmd(0x80);

lcd_string("OBJECT IDENTIFICATION");
lcd_cmd(0xC0);

lcd_string("USING RF COMMUNI.");
Delay(400);
while(1)
{

if(!SW1 && SW2 && SW3 && SW4)
{
BUZZER_ON();
Delay(60);
BUZZER_OFF();
lcd_cmd(0x01);
lcd_cmd(0x80);
lcd_string(" OBJECT ONE ");
send_sms1();
Delay(400);
}
if(SW1 && !SW2 && SW3 && SW4)
{
BUZZER_ON();
Delay(60);
BUZZER_OFF();
lcd_cmd(0x01);
lcd_cmd(0x80);
lcd_string(" OBJECT TWO ");
send_sms2();
Delay(400);
}
if(SW1 && SW2 && !SW3 && SW4)
{
BUZZER_ON();
Delay(60);
BUZZER_OFF();
lcd_cmd(0x01);
lcd_cmd(0x80);
lcd_string(" OBJECT THREE ");
send_sms3();
Delay(400);
}
if(SW1 && SW2 && SW3 && !SW4)
{
BUZZER_ON();
Delay(60);
BUZZER_OFF();
lcd_cmd(0x01);
lcd_cmd(0x80);
lcd_string(" OBJECT FOUR ");
send_sms4();
Delay(400);
}


}

}


void GSM_init()
{
u1_print("AT");
enter();
Delay(10);
u1_print( "ATE0");
enter();
Delay(10);
u1_print("AT+CMGF=1");
enter();
Delay(10);


}

void enter()
{
u1_byte(0x0D);
u1_byte(0x0A);
}

void send_sms1()
{
u1_print("AT+CMGS=\"09214659486\"");
enter();

u1_print("Object One Detected");
u1_byte(0x1A);
lcd_cmd(0x01);
lcd_string("MSG SENT");
Delay(200);
}

void send_sms2()
{
u1_print("AT+CMGS=\"09214659486\"");
enter();
u1_print("Second Object Detected");
u1_byte(0x1A);
lcd_cmd(0x01);
lcd_string("MSG SENT");
Delay(200);
}
void send_sms3()
{
u1_print("AT+CMGS=\"9036005512\"");
enter();
u1_print("Third Object Detected");
u1_byte(0x1A);
lcd_cmd(0x01);
lcd_string("MSG SENT");
Delay(200);
}
void send_sms4()
{
u1_print("AT+CMGS=\"9036005512\"");
enter();
u1_print("Fourth Object Detected");
u1_byte(0x1A);
lcd_cmd(0x01);
lcd_string("MSG SENT");
Delay(200);
}

while(1) loop is missing in the main() function.