Correctly receiving the nmea characters from A2200-A GPS

I have been working on this project for a little while, trying to receive the characters from my GPS and then display these characters on a 16×2 LCD. I am using an interrupt on my UART RX pin which allows the program to enter the interrupt service routine when a character is detected which is working.

In the interrupt service routine the NMEA data is then extracted and stored in a 80 character array and then broken down again into smaller arrays to extract the individual data I am wanting to display. However when I do go to display these characters I see nothing.

The LCD part of the program is working perfectly and I can see on my oscilloscope that characters are being transmitted by the GPS, so the problem might be that I am not storing this information properly and I have set the bit rates correctly?

The microcontroller that I am using is the PIC32mx795f512h, if anyone might know what my problem might be any help would be hugely appreciated.

Below is my main and interrupt service routine

int32_t main(void)
{
#ifndef PIC32_STARTER_KIT
    SYSTEMConfig(SYS_FREQ, SYS_CFG_WAIT_STATES | SYS_CFG_PCACHE);

    InitApp();             //initialise ports & interrupts
    intLCD();              //initialise LCD
    clrLCD();
    putsLCD("Initialising \n \t TCAS");


    // configure for multi-vectored mode
 INTConfigureSystem(INT_SYSTEM_CONFIG_MULT_VECTOR);

//UART1 enable for own gps
 UARTConfigure(UART1, UART_ENABLE_PINS_TX_RX_ONLY);
 UARTSetFifoMode(UART1, UART_INTERRUPT_ON_TX_NOT_FULL | UART_INTERRUPT_ON_RX_NOT_EMPTY);
 UARTSetLineControl(UART1, UART_DATA_SIZE_8_BITS | UART_PARITY_NONE | UART_STOP_BITS_1);
 UARTSetDataRate(UART1, GetPeripheralClock(), 4800);
 UARTEnable(UART1, UART_ENABLE_FLAGS(UART_PERIPHERAL | UART_RX | UART_TX));

 // Configure UART1 RX Interrupt
 INTEnable(INT_SOURCE_UART_RX(UART1), INT_ENABLED);
 INTSetVectorPriority(INT_VECTOR_UART(UART1), INT_PRIORITY_LEVEL_2);
 INTSetVectorSubPriority(INT_VECTOR_UART(UART1), INT_SUB_PRIORITY_LEVEL_0);


 //UART2 enable for surrounding


 PORTSetPinsDigitalOut(IOPORT_F, BIT_5);                    //data transmitter
 PORTSetPinsDigitalIn(IOPORT_F, BIT_4);                     //data receiver


 // enable interrupts
 INTEnableInterrupts();

 //allow uart >300ms to initialise
 Delayms(5000);

 gpsINITIALISE();        //initialise GPS to receive data >100ms

 //main loop
 int check = 0;
 while(1)     //wait in here for uart interrupt
 {
        ValidMsg = NotTrue;     //clear valid message variable
    if(check == 0)
    {
                    putsLCD("Resend \n \t message");
        sendMessages(); //send for gga message
        check = 1;
    }
          if(ValidMsg = True) //check to see if data is valid in main string
          {
               putsLCD("Message \n \t Valid");
               DisableIntU1RX;   //dissable interrupts on uart 1
               createString();   //create character string to transmit to nearby aircraft
               EnableIntU2RX;    //enable interrupts on UART2
               Delayms(10000);   //wait for data to be received from nearby aircraft
               DisableIntU2RX;   //dissable interrupts on uart 2
               GPStest();        //display the individual strings

          }
        if (ValidMsg = NotTrue) //check to see is not valid
          {
             putsLCD("Message1 \n \t Invalid");
             for(s=0; s<80; s++)        //clear received data string
                  {
                      GGA[s]=0;
                   }
             sendMessages(); //resend for gga message
           }
    }
}






// U1RX interrupt, majority of GPS relies within
void __ISR(_UART_1_VECTOR, ipl6) _U1RXInterrupt(void)
{
    int parse=0;    // string counter
if(U1STAbits.OERR == 1)
    U1STAbits.OERR = 0;

if(U1STAbits.URXDA) //check if data is ready to be read
    {
        c = getcUART1();
        while(UARTReceivedDataIsAvailable(UART1)); //check to see if data is available
        if(c == '$') //c == $, hex=0x0024
        {
            count = 0;
        }
        if(count < 6)
        {
            dataTest[count] = c;
            count++;
        }
        else if(count > 5 && count < 80)
        {
            if(dataTest[4]=='G')     //test data string
                               {
                         GGA[count]=c;
                                     ValidMsg = True;    //data is valid
                               }
            else  //error
                                ValidMsg = NotTrue;    //data is valid
                count++;
                                PORTToggleBits(IOPORT_B, BIT_2);
        }
    }

    //extract data into individual strings
            x=0;
    for(parse=1;parse<80;parse++)
    {

        if ((parse >=1) & (parse <6)) //Message Type
        {
            command[parse-1] = GGA[parse];
        }
        else if ((parse >6) & (parse < 17)) //Time
        {
            time[x] = GGA[parse];
            x++;
            if (parse == 16)
                x=0;
        }
        else if ((parse > 17) & (parse < 27)) //Latitude
        {
            lat[x] = GGA[parse];
            x++;
            if (parse == 26)
                x=0;
        }
        else if (parse == 28) //Latitude Dir
            latDir = GGA[parse];
        else if ((parse > 29) & (parse < 40)) //Longitude
        {
            lon[x] = GGA[parse];
            x++;

            if (parse == 39)
                x=0;
        }
        else if (parse == 41) //Longitude Dir
            lonDir = GGA[parse];
        else if (parse == 43) //Fix Quality

            fixQ = GGA[parse];
        else if ((parse > 51) & (parse < 55)) //altitude
        {
            altitude[x] = GGA[parse];
            x++;
            if(parse == 54)
            x=0;
        }
    }
    INTClearFlag(INT_SOURCE_UART_RX(UART1));         // Clear the RX interrupt Flag
}