GPSprogram

#include <Adafruit_GPS.h>
#include <SoftwareSerial.h>
#include <String.h>

SoftwareSerial gprsSerial(7, 8);
SoftwareSerial gpsSerial(3, 2);
Adafruit_GPS GPS(&gpsSerial);
#define GPSECHO  false

boolean usingInterrupt = false;
void useInterrupt(boolean); // Func prototype keeps Arduino 0023 happy

void setup(){
  String lat = "";
  String lon = "";
  Serial.begin(115200);
  GPS.begin(9600);
  GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCGGA);
  GPS.sendCommand(PMTK_SET_NMEA_UPDATE_1HZ);
  useInterrupt(true);
  delay(1000);
  // Ask for firmware version
  gpsSerial.println(PMTK_Q_RELEASE);
  }

SIGNAL(TIMER0_COMPA_vect){
 char c = GPS.read();
#ifdef UDR0
  if (GPSECHO)
    if (c) UDR0 = c;  
#endif
}

void useInterrupt(boolean v) {
if (v) {
        OCR0A = 0xAF;
        TIMSK0 |= _BV(OCIE0A);
        usingInterrupt = true; 
      }
 else{
      TIMSK0 &= ~_BV(OCIE0A);
      usingInterrupt = false;  
    }
  }

uint32_t timer = millis();
void loop(){                   // run over and over again
    if (! usingInterrupt) {
    char c = GPS.read();
    if (GPSECHO)
    if (c) Serial.print(c);  
    }

  if (GPS.newNMEAreceived()){ 
    if (!GPS.parse(GPS.lastNMEA()))   // this also sets the newNMEAreceived() flag to    false
    return;  // we can fail to parse a sentence in which case we should just wait for another
  }

  if (timer > millis())  timer = millis();
  if (millis() - timer > 2000){ 
    timer = millis(); // reset the timer  
    Serial.print("\nTime: ");
    Serial.print(GPS.hour, DEC); Serial.print(':');
    Serial.print(GPS.minute, DEC); Serial.print(':');
    Serial.print(GPS.seconds, DEC); Serial.print('.');
    Serial.println(GPS.milliseconds);
    Serial.print("Date: ");
    Serial.print(GPS.day, DEC); Serial.print('/');
    Serial.print(GPS.month, DEC); Serial.print("/20");
    Serial.println(GPS.year, DEC);
    Serial.print("Fix: "); Serial.print((int)GPS.fix);
    Serial.print(" quality: "); Serial.println((int)GPS.fixquality); 
    if (GPS.fix) 
    {
      Serial.print("Location: ");
      Serial.print(GPS.latitude, 4); Serial.print(GPS.lat);
      Serial.print(", "); 
      Serial.print(GPS.longitude, 4); Serial.println(GPS.lon);
      Serial.print("Location (in degrees, works with Google Maps): ");
      Serial.print(GPS.latitudeDegrees, 4);
      Serial.print(", "); 
      Serial.println(GPS.longitudeDegrees, 4);
      
      Serial.print("Speed (knots): "); Serial.println(GPS.speed);
      Serial.print("Angle: "); Serial.println(GPS.angle);
      Serial.print("Altitude: "); Serial.println(GPS.altitude);
      Serial.print("Satellites: "); Serial.println((int)GPS.satellites);  
      }  
    }  
  }