Parallax GPS is freezing up

Draetoxtheloon · 2011-10-14 13:07

Hi, I have a circuit containing a Parallax 28146 GPS serial module. I'm able to use the GPS in SMART mode and so I have created 3 buttons on my circuit. If Button1 is pressed then the LCD will display "# of Satellites = " followed by the actual number of satellites. Button2 shows the Lat/Long, and Button3 shows the Time of the Day.

The problem is kind of tough to troubleshoot (at least for me anyway), since I have three buttons when one is pressed it displays the corresponding data, then when a separate button is pressed the LCD is cleared and the proper information is displayed. The problem is every once in a while when I press the buttons there is no data showing on the LCD, as if something is "tied up" and is stuck in a loop or something.

Does anyone know what might be causing this??

I'm adding the code below which is in the majority of the functions:

#define gpsPin1 PORTCbits.RC0 
#define gpsTris1 TRISCbits.TRISC0 
#define gpsPin2 PORTCbits.RC1 
#define gpsTris2 TRISCbits.TRISC1 
#define gpsPin3 PORTCbits.RC2 
#define gpsTris3 TRISCbits.TRISC2  

ANSELCbits.ANSC2 = 0;

gpsTris1 = 1;
gpsTris2 = 1;
gpsTris3 = 1;

while(1)
    {

        if (gpsPin1 == 1)
        {
            Delay1KTCYx(10);
            gps = 1;
        }

        else if (gpsPin2 == 1)
        {
            Delay1KTCYx(10);
            gps = 2;
        }

        else if (gpsPin3 == 1)
        {
            Delay1KTCYx(10);
            gps = 3;
        }

        else
        {
            gps = 0;
        }

        switch(gps)
        {
            case 1:
            getSats();
            gps = 0;
            break;

            case 2:
            getLat();
            getLong();
            gps = 0;
            break;

            case 3:
            getTime();
            gps = 0;
            break;
        }
    }

while (receivecounter < 1)
    {
        if (PIR3bits.RC2IF)         //If USART RX buffer is full
        {
   
        if ((RCSTA2bits.FERR) || (RCSTA2bits.OERR))   //If there is a framing error or overrun
         {
            receivecounter = 6;
            temp2 = RCREG2;         // reading RCREG clears RCIF and FERR
    
            if(RCSTA2bits.OERR==1)
            {
                RCSTA2bits.CREN=0;      // OERRR is reset by clearing CREN
                RCSTA2bits.CREN=1;      // re-enable continuous receive
            }
        }
           else 
           {
               receivecounter++;
               temp2 = RCREG2;
        }
           }
    }
    
//----------The following code is for Satellites------//
        putrsXLCD("# of Sats = ");
        Delay1KTCYx(100);
        sprintf(idata, "%d", temp2);  //print # of Sats
        putsXLCD(idata);

Draetoxtheloon · 2011-10-14 13:10

The code above (ReceiveCounter loop) is similar for each function: Time, Lat/Long, and Sats. Although in Lat/Long I'm using a temp[] instead of variable temp2, temp2 and temp[] are both unsigned int variable types. Also in the each function the "while (receivecounter < num)" the num would be the number of bytes the function returns, Time = 3, Sats = 1, Lat/Long = 5

Parallax GPS is freezing up

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