   pinMode(soundSensor, INPUT);
   pinMode(buttonPin, INPUT);
 
-  //Serial.println(F(FreeRam()));
   dataFile = SD.open("test.csv", FILE_WRITE);
 
   // If the file opened okay, write to it:
   if (dataFile) {
-    //Serial.print("Writing to test.txt...");
-    dataFile.println("row,lat,lon,speed,timestamp,sound,luminosity,lux,ir,vibration");
-    // close the file:
+    //Serial.print("Writing header test.csv...");
+    dataFile.println("row,lat,lon,speed,timestamp,sound,luminosity,lux,ir,vibration,altitude");
+    // Close the file:
     dataFile.close();
     //Serial.println("done.");
   } else {
     // if the file didn't open, print an error:
-    Serial.println(F("error opening test.txt"));
+    Serial.println(F("Error opening test.csv"));
   }
 }
 

  }
  lastButtonState = buttonState;

  if (isOn == 1) {
    digitalWrite(LED, LOW);
    bool newData = false;

      // GPS reading done
      newData = false;

      //Light sensor
      uint32_t lum = tsl.getFullLuminosity();
      ir = lum >> 16;
