[PIC] PIC microcontoller communicating with two serial ports.

/*******************************************************************************/
//AT command set
char response[] = "OK";
char response2[] = "CONNECT OK";
char at1[] = "AT\r\n";
char csq[] = "AT+CSQ\r\n";
char creg[] = "AT+CREG?\r\n";
char cgatt[] = "AT+CGATT?\r\n";
char cstt[] = "AT+CSTT=\"AIRTELGPRS.COM\",\"\",\"\"\r\n";
char ciicr[] = "AT+CIICR\r\n";
char cifsr[] = "AT+CIFSR\r\n";
char cipstart[] = "AT+CIPSTART=\"TCP\",\"203.197.114.67\",\"6900\"\r\n";
char cipsend[] = "AT+CIPSEND\r\n";
char clts[12] = "AT+CLTS=1\r\n";
char cclk[11] = "AT+CCLK?\r\n";
char cgsn[10] = "AT+CGSN\r\n";
char prompt[] = "> ";
char err[] = "ERROR";
/*******************************************************************************/
char rxchar;                     //variable for storing data from UART1
int i = 0,j=0,count=0,msgs=0;   // array counter and flag to write once the desired pattern is read
char buf[1009];                // array to store the received charaters from UART1
char hexstrn[3],out[9];        //strings to convert hextostring
char *rc_ptr,*tx_ptr;          //pointers to point to the received data and transmitting data
enum{WAIT_FOR_1C,WAIT_FOR_3bytes,RECEIVING} state=WAIT_FOR_1C;   //state to check 
                                                                 //for the required chars
/*********************************************************************************/
char gsmbuf[200];           //storing data from gprs module
char timebuf[19]="14/05/29;15:24:45;"; //manual time buf
unsigned char imei[8];                 //stores imei number
char latlng[22] = "+24.345656;+80.878383" ;  //lat and lng manually entered
char chartosend;                      //check for > 
char databuf[70]="ERF;01;";             //data string
unsigned int packet=0;
/*********************************************************************************/
void Send_AT_cmd(char command[],char gsmbuffer[],char response[],char err[]){
int k=0;
 UART2_Write_Text(command);
  while(1){
  if(strstr(gsmbuffer,response)== 0){
  while(UART2_Data_Ready()==0);
  gsmbuffer[k]=UART2_Read();
  k++;
  }
  else break;
  if (strstr(gsmbuffer,err)!=0){
  LATA0_bit=1;
   }
  }
}
  //get imei number of the device
void getIMEI(unsigned char imei[]){
  int k=0;
  UART2_Write_Text(cgsn);
  while(strstr(gsmbuf,response)==0){
  while(UART2_Data_Ready()==0);
  gsmbuf[k]=UART2_Read();
  k++;
  }
  for(k=0;k<6;k++){
  imei[k]= *(strstr(gsmbuf,"OK") -11 + k);    //store the last 6 but 1 bytes
  }
memset(gsmbuf,'\0',200);  
}
/********************************************************************************/
//char *getTIME(char timebuf[],char gsmbuf[]){
//unsigned int k=0;
//memset(timebuf,'\0',50);
//UART2_Write_Text(cclk);                    //cclk command
//while(strstr(timebuf,"OK")==0){
//gsmbuf[k]=UART2_Read();
//k++;
//}
//*(strstr(gsmbuf,":")+20) = ';';
//*(strstr(gsmbuf,":")+21) = '\0';

//strcpy(timebuf,strstr(gsmbuf,"\"")+1) ;
//*(strstr(timebuf,",")) = ';';

//return(timebuf);
//}

//send data to server
void Send_Data(char databuf[]){
unsigned int k=0;
UART2_Write_Text(cipstart);     //ping the server
while(1){
if(strstr(gsmbuf,response2)!= 0){
   while(UART2_Data_Ready()==0);
   gsmbuf[k]=UART2_Read();
   k++;
  }
  else if(strstr(gsmbuf,"ALREADY CONNECTED")==0){
   break;
   }
  else if(strstr(gsmbuf,"CONNECT FAIL")==0){
     LATA2_bit=0;
    }
   else break;
}
 memset(gsmbuf,'\0',200);
 
UART2_Write_Text(cipsend);   //command to send data
while(1){
while(UART2_Data_Ready()==0);
chartosend = UART2_Read();
                            if(chartosend=='>'){
                             while(UART2_Data_Ready()==0);     //wait for the prompt >
                             chartosend = UART2_Read();
                              if(chartosend==' ') break;
                            }
}
UART2_Write_Text(databuf);   //send the data to gprs
UART2_Write(0x1A);
UART2_Read_Text(gsmbuf,"CLOSED",255); //close the connection
memset(gsmbuf,'\0',200);
}

/*******************************************************************************/
//interrupt service routine to read data from uart1
void interrupt () {
  if (RC1IF_bit == 1) {  
   LATC0_bit=1;   // test the interrupt for uart rx
     rxchar = UART1_Read();  //read a byte from UART1
      switch(state){
               case WAIT_FOR_1C:   //wait till 31 is arrived
              if(rxchar == 0x31) {
              state = WAIT_FOR_3bytes;
             
                
              }
                break;
               case WAIT_FOR_3bytes:
                i++;
                if(i>=3){
                 for(i=0;i<18;i++){
                 *rc_ptr=timebuf[i];    //I am attaching a manual time string 
                                               //please find the getTime function above which i thought to use
                                               //for getting date and time
                                               //getTime func is giving reentrancy errors
                 rc_ptr++;              
                 }
                 i=0;
                 state=RECEIVING;
                }
               break;
               case RECEIVING:
               if(count==168){
                  count=0;
                  rc_ptr=buf;
               }
               *rc_ptr=rxchar;
               rc_ptr++;
               count++;
               if(count%4==0){
               rc_ptr=rc_ptr+2;
               msgs=msgs+1;
               state=WAIT_FOR_1C ;
               }
               break;
   } // end interrupt
  }
  if(OERR1_bit){
    LATA=0xFF;
  }
  }
  /******************************************************************************/
/*******************************************************************************/
void main() {

     ANSELA = 0x00;
     ANSELB = 0x00;
     ANSELC = 0x00;
     ANSELD = 0x00;

     TRISA = 0xFF;
     PORTA = 0x00;
     LATA = 0xFF;
     TRISB = 0x00;
     PORTB = 0x00;
     LATB = 0x00;
     TRISC = 0xC0;
     PORTC = 0x00;
     LATC = 0x00;
     TRISD = 0xC0;
     PORTD = 0x00;
     LATD = 0x00;
     
      UART2_Init(9600);
     Delay_ms(2000);
      //RC2IE_bit = 1; 
     UART1_Init(19200);
 Delay_ms(100);
 

 //INTCON.GIE = 1;      //enable global interrupt
 //INTCON.PEIE = 1;
 //PIE1.RCIE = 1; //enable receive interrupt.
 RC1IE_bit = 1;                    // turn ON interrupt on UART1 receive
  RC1IF_bit = 0;                    // Clear interrupt flag
  PEIE_bit  = 1;                    // Enable peripheral interrupts
  GIE_bit   = 1;                    // Enable GLOBAL interrupts

    rc_ptr=buf;
    tx_ptr=buf;
    UART1_Write_Text("start");
     
     Send_AT_cmd(at1,gsmbuf,response,err);        //send at
     memset(gsmbuf,'\0',200);
     
     getIMEI(imei);                     //get imei
     
     Send_AT_cmd(creg,gsmbuf,response,err);          //send at+creg
     if(*(strstr(gsmbuf,":")+4) != ('1'||'5')) {
         LATA1_bit =0;
     }
     memset(gsmbuf,'\0',200);
     Send_AT_cmd(cgatt,gsmbuf,response,err);
     if(*(strstr(gsmbuf,":")+2) == '1'){
     LATB=0xFF;
     }
      memset(gsmbuf,'\0',200);
      Send_AT_cmd(cstt,gsmbuf,response,err);
      memset(gsmbuf,'\0',200);
      Send_AT_cmd(clts,gsmbuf,response,err);
       memset(gsmbuf,'\0',200);
       Send_AT_cmd(ciicr,gsmbuf,response,err);
       memset(gsmbuf,'\0',200);
       UART2_Write_Text(cifsr);
       Delay_ms(2000);
       
 
 while(1) {   // Begin endless loop
  // This section is where you tell the program what to do with the data once it
  // has all arrived
   Delay_ms(100);
     while(msgs!=0){         //read all the messages
                  
   //when i get a string i store 24 bbytes including date,time and some data from the rf receiver 
                  for(j=0;j<4;j++){
                   ByteToHex(*(tx_ptr+19),hexstrn);     //convert input data to string
                   strcat(out,hexstrn);
                   tx_ptr++;
                  }
                  tx_ptr=tx_ptr+2;    //increment the tx_ptr to avoid errors
                  out[9]=';';
                  strcpy(&databuf[7],out);
                  strcpy(&databuf[17],tx_ptr);
                  sprintf(&databuf[34],"%s;%s;%4u#",latlng,imei,packet); //create the string to be sent
                  packet++;
                  if(packet == 10000){
                  packet=0;     //if 10000 packets sent reset
                  }
                   UART1_Write_Text(databuf);
                  memset(out,'\0',10);
                  UART1_Write(13);          //new line char   
                  Send_Data(databuf);    //send the data

   if( tx_ptr - buf ==1008){      //if tx_ptr reaches the end of buffer loop back to beginning
   tx_ptr = buf;
   }
   msgs=msgs-1;
      }
 } // end while
       
     
     
     
}