SD card creates file but does not write.

I am using the adafruit micro sd breakout board to log data from some sensors. When trying to log my data from the GPS sensor (Adafruit Ultimate GPS v3) it will create the file on the SD card but that is all. The test codes from the sd library work fine. Cardinfo generates the proper information, and ReadWrite does fine as well. I have switched the card and the breakout board with one from other sensors that work fine, and still get nothing. The first board and card combination work just fine with my other sensors, so perhaps it is an error with the code.

Any help would be appreciated

// Test code for Adafruit GPS modules using MTK3329/MTK3339 driver
// This code shows how to listen to the GPS module in an interrupt
// which allows the program to have more ‘freedom’ - just parse
// when a new NMEA sentence is available! Then access data when
// desired.
// Tested and works great with the Adafruit Ultimate GPS module
// using MTK33x9 chipset
// ------>
// Pick one up today at the Adafruit electronics shop
// and help support open source hardware & software! -ada

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

File myFile;

// If you’re using a GPS module:
// Connect the GPS Power pin to 5V
// Connect the GPS Ground pin to ground
// If using software serial (sketch example default):
// Connect the GPS TX (transmit) pin to Digital 3
// Connect the GPS RX (receive) pin to Digital 2
// If using hardware serial (e.g. Arduino Mega):
// Connect the GPS TX (transmit) pin to Arduino RX1, RX2 or RX3
// Connect the GPS RX (receive) pin to matching TX1, TX2 or TX3

// If you’re using the Adafruit GPS shield, change
// SoftwareSerial mySerial(3, 2); → SoftwareSerial mySerial(8, 7);
// and make sure the switch is set to SoftSerial

// If using software serial, keep this line enabled
// (you can change the pin numbers to match your wiring):
SoftwareSerial mySerial(3, 2);

// If using hardware serial (e.g. Arduino Mega), comment out the
// above SoftwareSerial line, and enable this line instead
// (you can change the Serial number to match your wiring):

//HardwareSerial mySerial = Serial1;

Adafruit_GPS GPS(&mySerial);

// Set GPSECHO to ‘false’ to turn off echoing the GPS data to the Serial console
// Set to ‘true’ if you want to debug and listen to the raw GPS sentences.
#define GPSECHO false

// this keeps track of whether we’re using the interrupt
// off by default!
boolean usingInterrupt = false;
void useInterrupt(boolean); // Func prototype keeps Arduino 0023 happy

void setup()

// connect at 115200 so we can read the GPS fast enough and echo without dropping chars
// also spit it out
//Serial.println(“Adafruit GPS library basic test!”);
Serial.print(“Initializing SD card…”);
// On the Ethernet Shield, CS is pin 4. It’s set as an output by default.
// Note that even if it’s not used as the CS pin, the hardware SS pin
// (10 on most Arduino boards, 53 on the Mega) must be left as an output
// or the SD library functions will not work.
pinMode(10, OUTPUT);

if (!SD.begin(10)) {
Serial.println(F(“initialization failed!”));
Serial.println(F(“initialization done.”));


// uncomment this line to turn on RMC (recommended minimum) and GGA (fix data) including altitude
// uncomment this line to turn on only the “minimum recommended” data
// For parsing data, we don’t suggest using anything but either RMC only or RMC+GGA since
// the parser doesn’t care about other sentences at this time

// Set the update rate
GPS.sendCommand(PMTK_SET_NMEA_UPDATE_1HZ); // 1 Hz update rate
// For the parsing code to work nicely and have time to sort thru the data, and
// print it out we don’t suggest using anything higher than 1 Hz

// Request updates on antenna status, comment out to keep quiet

// the nice thing about this code is you can have a timer0 interrupt go off
// every 1 millisecond, and read data from the GPS for you. that makes the
// loop code a heck of a lot easier!

// Ask for firmware version

// Interrupt is called once a millisecond, looks for any new GPS data, and stores it
char c =;
// if you want to debug, this is a good time to do it!
#ifdef UDR0
if (c) UDR0 = c;
// writing direct to UDR0 is much much faster than Serial.print
// but only one character can be written at a time.

void useInterrupt(boolean v) {
if (v) {
// Timer0 is already used for millis() - we’ll just interrupt somewhere
// in the middle and call the “Compare A” function above
OCR0A = 0xAF;
usingInterrupt = true;
} else {
// do not call the interrupt function COMPA anymore
usingInterrupt = false;

uint32_t timer = millis();
void loop() // run over and over again
myFile =“GPS.txt”, FILE_WRITE);
// in case you are not using the interrupt above, you’ll
// need to ‘hand query’ the GPS, not suggested :frowning:
if (! usingInterrupt) {
// read data from the GPS in the ‘main loop’
char c =;
// if you want to debug, this is a good time to do it!
if (c) Serial.print(c);

// if a sentence is received, we can check the checksum, parse it…
if (GPS.newNMEAreceived()) {
// a tricky thing here is if we print the NMEA sentence, or data
// we end up not listening and catching other sentences!
// so be very wary if using OUTPUT_ALLDATA and trytng to print out data
Serial.println(GPS.lastNMEA()); // this also sets the newNMEAreceived() flag to false

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 millis() or timer wraps around, we’ll just reset it
if (timer > millis()) timer = millis();

// approximately every 5 seconds or so, print out the current stats
if (millis() - timer > 5000) {
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.print(“Date: “);
Serial.print(GPS.month, DEC); Serial.print(’/’);
Serial.print(, DEC); Serial.print(”/20”);
Serial.println(GPS.year, DEC);

myFile.print("\nTime: ");
myFile.print(GPS.hour, DEC); myFile.print(’-’);
myFile.print(GPS.minute, DEC); myFile.print(’-’);
//myFile.print(GPS.seconds, DEC); myFile.print(’.’);
myFile.print(F(“Date: “));
myFile.print(GPS.month, DEC); myFile.print(’/’);
myFile.print(, DEC); myFile.print(F(”/20”));
myFile.println(GPS.year, DEC);

if (GPS.fix) {
Serial.print(F("Location: “));
Serial.print(GPS.latitude, 4); Serial.print(;
Serial.print(F(”, "));
Serial.print(GPS.longitude, 4); Serial.println(GPS.lon);
Serial.print(F("Location (in degrees, works with Google Maps): “));
Serial.print(GPS.latitudeDegrees, 4);
Serial.print(F(”, "));
Serial.println(GPS.longitudeDegrees, 4);
Serial.print(F("Speed (knots): ")); Serial.println(GPS.speed);
Serial.print(F("Angle: ")); Serial.println(GPS.angle);
Serial.print(F("Altitude: ")); Serial.println(GPS.altitude);

myFile =“GPS_Parsed.txt”, FILE_WRITE);
myFile.print(F("Location: “));
myFile.print(GPS.latitude, 4); myFile.print(;
myFile.print(F(”, "));
myFile.print(GPS.longitude, 4); myFile.println(GPS.lon);
myFile.print(F("Location (in degrees, works with Google Maps): “));
myFile.print(GPS.latitudeDegrees, 4);
myFile.print(F(”, "));
myFile.println(GPS.longitudeDegrees, 4);
//myFile.print("Speed (knots): "); myFile.println(GPS.speed);
//myFile.print("Angle: "); myFile.println(GPS.angle);
//myFile.print("Altitude: "); myFile.println(GPS.altitude);