GPS.ino

void readGPS(){
 smartDelay(400);
 if(gps.location.isValid()){ 
  latit = gps.location.lat(); longit = gps.location.lng(); }
 if(gps.altitude.isValid()){ 
    alto = alt;
    alt = gps.altitude.meters(); 

    double currvel = (alt - alto);
    vel[0] = vel[1]; vel[1] = vel[2]; vel[2] = vel[3]; vel[3] = vel[4]; vel[4] = currvel;
    velDiff = (vel[0] + vel[1] + vel[2] + vel[3] + vel[4])/5;
 }
 if(gps.time.isValid()){ gpstime = gps.time.value(); }
 if(gps.date.isValid()){ gpsdate = gps.date.value(); }
 if(gps.satellites.isValid()){ numsats = gps.satellites.value(); }
 if(gps.course.isValid()){ course = gps.course.deg(); }
 if(gps.speed.isValid()){ speed = gps.speed.mph(); }
 delay(10);
}

static void smartDelay(unsigned long ms){
  unsigned long start = millis();
  do 
  {
    while (Serial2.available() && (!gps.altitude.isUpdated()) ) {
      gps.encode(Serial2.read()); 
    }
  } 
  
  while (millis() - start < ms);
}