[51] SMS receiving through sim300 with 8051

[Sudhp]

HI,
I am trying to read msg from gsm modem, Sometimes it happens bt sometimes i m unable to read msg,it is giving a junk value on lcd.

I m using below codes to read msg from modem. I have downloaded these codes from net can u guys please help me by providing me mistakes in these codes. So i read msg properly.

void main (void)
{
rw=0;
clear();
init();
lcd_init();

SMSString("AT\r"); // AT commands to initialize gsm modem
delay_sms(1000);

SMSString( "ATe0\r"); // turn off echo
delay_sms(1000);

SMSString( "AT&W\r"); // save settings
delay_sms(1000);

SMSString( "AT+CMGF=1\r"); // select text mode for sms
delay_sms(1000);

SMSString( "AT+CNMI=2,2,0,0,0\r"); // notification of new sms
delay_sms(1000);

SMSString( "AT+CMGR=1\r"); // AT command to read sms

IE=0X90;   // Enable serial interrupt
delay_sms(5000);



// read sms and store in buffer msg1

read_text(msg1,rec_no,time_date);
clear();
IE=0X00;     // Disable all interrupt
while(1);
}
void read_text( unsigned char *msg,unsigned char *no ,unsigned char *time)
{
unsigned char *temp;
temp=msg;
do
msg++;
while(*msg!='+');        
do
msg++;
while(*msg!='+');         //  reaching at no
do
*no++=*msg++;
while(*msg!='"');         // reaching at time
*no++='\0';
msg++;
msg++;
msg++;
do
*time++=*msg++;
while(*msg!='+');         // raching at message
*time='\0';
do
msg++;
while(*msg!='\n');
msg++;
do
*temp++=*msg++;
while(*msg!='\r');       // reaching at end of message
*temp='\0';

lcd_cmd(0x80);            // ist line address
lcd_str(rec_no);          // array having receipt no
lcd_cmd(0xc0);            // 2nd line address
lcd_str(msg1);            // array having message
}

 

[Azzy anxious]

can anybody tell me that why this command is used?
AT+CNMI=2,2,0,0,0\r
And what these no. 2,2,0,0,1 stands for...........

How can the msgs be deleted position-vise ?
And on deleting the msgs by at command the other msgs shifts there position or not ?