[poll] Vehicle Tracking using GPS

hey ajay,
i started developing the uC code for the above project. but i am going through a lot of probs..

I am trying to send data through GPRS via SIM300 modem. The logic of my program should be.
t should send the data till it receives "dieman" from the server.

AT
OK
AT+CGATT=1
OK
AT+CGDCONT=1,"IP","airtelgprs.com"
OK
AT+CSTT="airtelgprs.com","",""
OK
AT+CIICR
OK
AT+CIFSR
212.22.22.22                  //EG OF AN IP ADDRESS
AT+CIPSTART="TCP","http://www.google.com","80"
OK

CONNECT OK
AT+CIPSEND
>
THIS IS THE DATA I WANNA SEND             // YOU CAN SEND THE DATA VIA GPRS NOW
 [CTRL+Z]
SEND OK

this is the code which i would like to implement

now i implemented the C version but my code is very inefficient. I could have ignored the response from the modem by simply inserting delays but i want my code such that if the reply from the modem is not "OK" it should transmit the command again.
the C code is as follows

#include<reg52.h>

#include<string.h>


unsigned char msg1[100],x=0;
unsigned char *s1="AT";
unsigned char *s2="AT+CGATT=1";
unsigned char *s3="AT+CGDCONT=1,\”airtelgprs.com\”";
unsigned char *s4="AT+CSTT=\”airtelgprs.com\”,\""\",\"""\";
unsigned char *s5="AT+CIICR";
unsigned char *s6="AT+CIFSR";
unsigned char *s7="AT+CIPSTART=\”TCP\”,\”http://www.google.com\”,\”80\””;
unsigned char *s8="AT+CIPSEND";
unsigned char *s9="AT+CLOSE";
unsigned char *s10="AT+SHUT";

void send(unsigned char *x)
{
    while(*x!='0')
    tx(*x);
}

void tx(unsigned char x)
{
   SBUF=x;
   while(TI==0);
   TI=0;
}

void delay(void)
{
  unsigned int i;
  for(i=0,i<=65535;i++);
}
void serialinit()
{
   IE=0X90;
   TMOD=0X20;
   TH1=0XFD;
   SCON=0X50H;
   TRI=1;
}

void serialrx(void) interrupt 4
{
   msg1[x]=SBUF;
   RI=0;
   x++;
}

void main()
{
char ch;
serialinit();

do
{
send(s1);                                    //send AT
delay();
if(!strncmp(msg,"\r\nOK",4))                   //compare if OK is received
   ch=1;
else ch=0;
}
while(ch==0);

do
{
send(s2);                                    //send AT+CGATT=1
delay();
if(!strncmp(msg,"\r\nOK",4))                   //compare if OK is received
   ch=1;
else ch=0;
}
while(ch==0);

do
{
send(s3);                                    //send AT+CGDCONT=1,"IP","airtelgprs.com"

delay();
if(!strncmp(msg,"\r\nOK",4))                   //compare if OK is received
   ch=1;
else ch=0;
}
while(ch==0);

do
{
send(s4);                                    //send AT+CSTT="airtelgprs.com","",""

delay();
if(!strncmp(msg,"\r\nOK",4))                   //compare if OK is received
   ch=1;
else ch=0;
}
while(ch==0);

do
{
send(s5);                                    //send AT+CIICR

delay();
if(!strncmp(msg,"\r\nOK",4))                   //compare if OK is received
   ch=1;
else ch=0;
}
while(ch==0);

do
{
send(s6);                                    //send AT+CIFSR

delay();
if(msg[3]>
=48 || msg<=57)  // its an ip address so it has to be a no. so ascii value compared
   ch=1;
else ch=0;
}
while(ch==0);

send(s7);             // SEND   AT+CIPSTART="TCP","http://www.google.com","80"

delay();              // now here there are 2 responses OK   CONNECT OK i dont how to compare
                       // and hence i am just waiting for sometime

send(s8);
while(msg(0)!='>
');
while(strncmp(msg,"\r\ndieman")!=0)
     send("this is what i want to send");
do
{
send(s9);                                    //send AT+CIPCLOSE
delay();
if(!strncmp(msg,"\r\nOK",4))                   //compare if OK is received
   ch=1;
else ch=0;
}
while(ch==0);

do
{
send(s10);                                    //send AT+CIPSHUT
delay();
if(!strncmp(msg,"\r\nOK",4))                   //compare if OK is received
   ch=1;
else ch=0;
}
while(ch==0);
}

pls help me find the correct code

@ shirazi2589
directly going to a full code in GSM is difficult task
do it step by step even with a simple AT command
now there are some commands that has other parameters not OK response then u ahs to check that also if u use that and if u use simple commands that has only OK response then has to concentrate on this
do it as
suppose u send this command
AT+CIPSEND
after this u has to send enter as in ur code ur not sending it
send it as
unsigned char *s1="AT/r";
instead of
unsigned char *s1="AT";
after this u has to wait for ok

while(RI==0);
if(SBUF=='O')
{
RI=0;
while(RI==0);
if(SBUF=='K')
{
RI=0;
// u receive ok now send next command
}
}
else
{
// send command again
}

go ahead step by step then it will be easy

hello,
can u plz tell me ,is gps has also At command like GSM?
how i can extract data(ALT,Long,speeed etc) from gps masg.
plz remove my confusion.

@ yashshailesh
GPS send a string of data in NMEA format
see this
http://www.kh-gps.de/nmea-faq.htm
normally it send a string @ 1HZ
then u has to find out the data u want from the string

hey ajay and all,

i am having a problem in setting remote connection via telnet..this is what i am doing.

in my services.msc i have activated TELNET and disabled firewall there.
i asked my friend to do the same. i then asked for his ip from whatsmyip.com. he then gave me the ip. i then asked him to activate the TCP SERVER at port 4444. i the typed on my cmd.

telnet IP add 4444

but Connecting To IP add..Could not open connection to the host, on port 4444:
Connect failed

what should i do..

as you said

make one of your PC as a server, put WAMPP and Java app on it to make a server.

how should i do it..

pls help

but Connecting To IP add..Could not open connection to the host, on port 4444:
Connect failed

shirazi2589

Have disabled your firewall in Settings ->Firewall.

Does your friend have a router, and if so, has he set up port forewarding ?

What TCP SERVER is he setting up ?

Have disabled your firewall in Settings ->Firewall.

yes i have disabled my and his firewall

Does your friend have a router, and if so, has he set up port forewarding ?

He has a router and the port 4444 is forwarded...

What TCP SERVER is he setting up ?

he is setting up a server called Hercules SW...below is the image