Arduino soll GPS Daten auswerten

[Spacecam]

Ich habe das SainSmart LCD Keypad Shield, das läuft wie oben im Script dargestellt ist.
Mit geht's wirklich nur um die Auswertung des GPS strings der per UART ankommt. Wie schließe ich ihn an, wie lese und werte ich ihn aus.

Quelle:
http://playground.arduino.cc/Tutorials/GPS

#include <string.h>
 #include <ctype.h>


 int ledPin = 13;                  // LED test pin
 int rxPin = 0;                    // RX PIN 
 int txPin = 1;                    // TX TX
 int byteGPS=-1;
 char linea[300] = "";
 char comandoGPR[7] = "$GPRMC";
 int cont=0;
 int bien=0;
 int conta=0;
 int indices[13];


 void setup() {
   pinMode(ledPin, OUTPUT);       // Initialize LED pin
   pinMode(rxPin, INPUT);
   pinMode(txPin, OUTPUT);
   Serial.begin(38400);
   for (int i=0;i<300;i++){       // Initialize a buffer for received data
     linea[i]=' ';
   }   
 }


 void loop() {
   digitalWrite(ledPin, HIGH);
   byteGPS=Serial.read();         // Read a byte of the serial port
   if (byteGPS == -1) {           // See if the port is empty yet
     delay(100); 
   } else {
     // note: there is a potential buffer overflow here!
     linea[conta]=byteGPS;        // If there is serial port data, it is put in the buffer
     conta++;                      
     //Serial.write(byteGPS); 
     if (byteGPS==13){            // If the received byte is = to 13, end of transmission
       // note: the actual end of transmission is <CR><LF> (i.e. 0x13 0x10)
       digitalWrite(ledPin, LOW); 
       cont=0;
       bien=0;
       // The following for loop starts at 1, because this code is clowny and the first byte is the <LF> (0x10) from the previous transmission.
       for (int i=1;i<7;i++){     // Verifies if the received command starts with $GPR
         if (linea[i]==comandoGPR[i-1]){
           bien++;
         }
       }
       if(bien==6){               // If yes, continue and process the data
         for (int i=0;i<300;i++){
           if (linea[i]==','){    // check for the position of the  "," separator
             // note: again, there is a potential buffer overflow here!
             indices[cont]=i;
             cont++;
           }
           if (linea[i]=='*'){    // ... and the "*"
             indices[12]=i;
             cont++;
           }
         }
         Serial.println("");      // ... and write to the serial port
         Serial.println("");
         Serial.println("---------------");
         for (int i=0;i<12;i++){
           switch(i){
             case 0 :Serial.print("Time in UTC (HhMmSs): ");break;
             case 1 :Serial.print("Status (A=OK,V=KO): ");break;
             case 2 :Serial.print("Latitude: ");break;
             case 3 :Serial.print("Direction (N/S): ");break;
             case 4 :Serial.print("Longitude: ");break;
             case 5 :Serial.print("Direction (E/W): ");break;
             case 6 :Serial.print("Velocity in knots: ");break;
             case 7 :Serial.print("Heading in degrees: ");break;
             case 8 :Serial.print("Date UTC (DdMmAa): ");break;
             case 9 :Serial.print("Magnetic degrees: ");break;
             case 10 :Serial.print("(E/W): ");break;
             case 11 :Serial.print("Mode: ");break;
             case 12 :Serial.print("Checksum: ");break;
           }
          
           for (int j=indices[i];j<(indices[i+1]-1);j++){
            
            
             Serial.print(linea[j+1]); 
             
           }
           Serial.println("");
         }
         Serial.println("---------------");
       }
       conta=0;                    // Reset the buffer
       for (int i=0;i<300;i++){    //  
         linea[i]=' ';             
       }                 
     }
   }
 }

Dieser Script läuft. Ich bin nur nicht in der Lage die Daten auf meinem Display anzuzeigen^^
LG