GSM MODEM with 8051

Hi mojaka,

In read_text () if i do like as below its working.

void read_msg()
{
unsigned char temp[20],i,j;
i=0;
j=0;
do
{
i++;
}while(msg1[i]!='+');
do
{
 i++;
}while(msg1[i]!='\n');
do
{
i++;  // I REMOVED TEMP[j]
}while(msg1[i]!='\r');
       
lcdcmd(0x80);          
lcdstr(msg1);            // array having message
delay(20);
}  

Now the LCD displays whatever in msg1[] Fyi controller auto resetting problem is solved after removing temp[j++]=msg1[i];
But now how do i format the msg1 array. I tried your pointer method also but controller reset problem occurs.

hi kirangowle
i try to change ur code according to my thinking
try is is any improvement occur
see it and update
i change Proteus schmetic as i want to say u
connect modem to pc serial port no 1 through a max 232
now u will see both commands r going tto modem and modem is responding
u will see it in Proteus

Hi,

Is SIM 300 Modem supports GPS,
Because i m planning to learn GPS/GPRS, since now i have modem what ever i can extract from it.
Pls help.

hi kirangowle

Is SIM 300 Modem supports GPS,

refer to its data sheet and also let me know
i think it not support

Hi Mojaka,
SIM 300 doesnt support GPS. It only supports GSM and GPRS.

How to send msgs via GSM modem through 8051.
I know the commands, but at last how to send ctrl+z strings.

First connect GSM modem to PC and then to microcontroller this check out this site

http://www.developershome.com/sms/howToUseHyperTerminal.asp

ctrl+z is not strings its equivalent ascii code is 26 in decimal for more information check out this site

http://www.jimprice.com/jim-asc.shtml

hi kirangowle

SIM 300 doesnt support GPS. It only supports GSM and GPRS.

thank u i was little confident that it is just gsm modem

How to send msgs via GSM modem through 8051.
I know the commands, but at last how to send ctrl+z strings.

ctrl+z=1A
send 1A at the end of message
for information read these documentations
http://www.jimprice.com/jim-asc.shtml
http://www.bbdsoft.com/ascii.html
download some documentation

1) http://ifile.it/m7afd3k
or
2) http://ifile.it/m7afd3k/GSM.rar

Hi,

SMSString( "AT+CMGF=1\r"); // select text mode for sms
delay(50);
while(1)
{
while(key!=1)
{
SMSString("AT+CMGS=\"9845xxxxxx\"\r");
delay(1);
SMSString("This is a test msg");
tx0(0x1A); // for ctrl+z;
}
}

Is it correct.
But i m not getting the output.

while(key!=1) ??
where are you updating this variable "key"?

Hi,
Key is P1.3. It will be checking for 0, if this pin is 0 then msg should be sent. it is entering into the loop i have checked on LCD. But its not sending msg.