Arduino GPS Shield by iteadstudio.com

Hello guys I have the same GPS Shield

I was hoping someone can help please,I want to Log the data to the on board SD slot on the GPS shield
But it doesn't seem to log the data to my SD Card
Here is my code it is composed between a tutorial from Jerermy Blum and the Sample GPS code,and PaulS's advice

#include <TinyGPS.h>
#include <SD.h>
#include <stdlib.h>
#include <SoftwareSerial.h>

TinyGPS gps;
static char dtostrfbuffer[20];
const int chipSelect = 10;
int LED = 13;

//Define String
String SD_date_time = "invalid";
String SD_lat = "invalid";
String SD_lon = "invalid";
String dataString ="";

static void gpsdump(TinyGPS &gps);
static bool feedgps();
static void print_float(float val, float invalid, int len, int prec, int SD_val);
static void print_int(unsigned long val, unsigned long invalid, int len);
static void print_date(TinyGPS &gps);
static void print_str(const char *str, int len);

void setup()
{
//Serial interfaces
Serial.begin(9600);

pinMode(10, OUTPUT); //Chip Select Pin for the SD Card
pinMode(LED, OUTPUT); //LED Indicator

//Connect to the SD Card
if (!SD.begin(chipSelect))
{
Serial.println("Card Failure");
return;
}

Serial.print("Testing TinyGPS library v. "); Serial.println(TinyGPS::library_version());
Serial.println("by Mikal Hart");
Serial.println();
Serial.print("Sizeof(gpsobject) = "); Serial.println(sizeof(TinyGPS));
Serial.println();
Serial.println("Sats HDOP Latitude Longitude Fix Date Time Date Alt Course Speed Card Distance Course Card Chars Sentences Checksum");
Serial.println(" (deg) (deg) Age Age (m) --- from GPS ---- ---- to London ---- RX RX Fail");
Serial.println("--------------------------------------------------------------------------------------------------------------------------------------");
}

void loop()
{
bool newdata = false;
unsigned long start = millis();

// Every second we print an update
while (millis() - start < 1000)
{
if (feedgps())
newdata = true;
}

gpsdump(gps);

//Write the newest information to the SD Card
dataString = SD_date_time + "," + SD_lat + "," + SD_lon;
if (SD_date_time != "invalid")
digitalWrite(LED, HIGH);
else
digitalWrite(LED, LOW);

//Open the Data CSV File
File dataFile = SD.open("LOG.csv", FILE_WRITE);
if (dataFile)
{
dataFile.println(dataString);
Serial.println(dataString);
dataFile.close();
}
else
{
Serial.println("\nCouldn't open the log file!");
}
}

static void gpsdump(TinyGPS &gps)
{
float flat, flon;
unsigned long age, date, time, chars = 0;
unsigned short sentences = 0, failed = 0;
static const float LONDON_LAT = 51.508131, LONDON_LON = -0.128002;

print_int(gps.satellites(), TinyGPS::GPS_INVALID_SATELLITES, 5);
print_int(gps.hdop(), TinyGPS::GPS_INVALID_HDOP, 5);
gps.f_get_position(&flat, &flon, &age);
print_float(flat, TinyGPS::GPS_INVALID_F_ANGLE, 9, 5, 1); //LATITUDE
print_float(flon, TinyGPS::GPS_INVALID_F_ANGLE, 10, 5, 2); //LONGITUDE
print_int(age, TinyGPS::GPS_INVALID_AGE, 5);

print_date(gps); //DATE AND TIME

print_float(gps.f_altitude(), TinyGPS::GPS_INVALID_F_ALTITUDE, 8, 2, 0);
print_float(gps.f_course(), TinyGPS::GPS_INVALID_F_ANGLE, 7, 2, 0);
print_float(gps.f_speed_kmph(), TinyGPS::GPS_INVALID_F_SPEED, 6, 2, 0);
print_str(gps.f_course() == TinyGPS::GPS_INVALID_F_ANGLE ? "*** " : TinyGPS::cardinal(gps.f_course()), 6);
print_int(flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0UL : (unsigned long)TinyGPS::distance_between(flat, flon, LONDON_LAT, LONDON_LON) / 1000, 0xFFFFFFFF, 9);
print_float(flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : TinyGPS::course_to(flat, flon, 51.508131, -0.128002), TinyGPS::GPS_INVALID_F_ANGLE, 7, 2, 0);
print_str(flat == TinyGPS::GPS_INVALID_F_ANGLE ? "*** " : TinyGPS::cardinal(TinyGPS::course_to(flat, flon, LONDON_LAT, LONDON_LON)), 6);

gps.stats(&chars, &sentences, &failed);
print_int(chars, 0xFFFFFFFF, 6);
print_int(sentences, 0xFFFFFFFF, 10);
print_int(failed, 0xFFFFFFFF, 9);
Serial.println();
}

static void print_int(unsigned long val, unsigned long invalid, int len)
{
char sz[32];
if (val == invalid)
strcpy(sz, "*******");
else
sprintf(sz, "%ld", val);
sz[len] = 0;
for (int i=strlen(sz); i<len; ++i)
sz = ' ';

• if (len > 0)*
• sz[len-1] = ' ';*
• Serial.print(sz);*
• feedgps();*
  }
  static void print_float(float val, float invalid, int len, int prec, int SD_val)
  {
• char sz[32];*
• if (val == invalid)*
• {*
  _ strcpy(sz, "*******");_
• sz[len] = 0;*
• if (len > 0)*
• sz[len-1] = ' ';*
• for (int i=7; i<len; ++i)*
  _ sz = ' ';_
  * Serial.print(sz);*
  * if(SD_val == 1) SD_lat = sz;
  else if(SD_val == 2) SD_lon = sz;
  _ }_
  _ else*_
  * {*
  * Serial.print(val, prec);*
  * if (SD_val == 1) SD_lat = dtostrf(val,10,5,dtostrfbuffer);
  else if (SD_val == 2) SD_lon = dtostrf(val,10,5,dtostrfbuffer);
  _ int vi = abs((int)val);_
  _ int flen = prec + (val < 0.0 ? 2 : 1);_
  _ flen += vi >= 1000 ? 4 : vi >= 100 ? 3 : vi >= 10 ? 2 : 1;_
  _ for (int i=flen; i<len; ++i)_
  _ Serial.print(" ");_
  _ }_
  _ feedgps();_
  _}_
  static void print_date(TinyGPS &gps)
  _{_
  _ int year;_
  _ byte month, day, hour, minute, second, hundredths;_
  _ unsigned long age;_
  gps.crack_datetime(&year, &month, &day, &hour, &minute, &second, &hundredths, &age);
  if (age == TinyGPS::GPS_INVALID_AGE)
  _ {_
  _ Serial.print("****** ******* ");
  * SD_date_time = "invalid";
  _ }*
  * else*
  * {*
  * char sz[32];*
  * sprintf(sz, "%02d/%02d/%02d %02d:%02d:%02d ",*
  * month, day, year, hour, minute, second);*
  * Serial.print(sz);*
  * SD_date_time = sz;
  _ }_
  print_int(age, TinyGPS::GPS_INVALID_AGE, 5);
  _ feedgps();_
  _}_
  static void print_str(const char str, int len)
  _{_
  * int slen = strlen(str);*
  * for (int i=0; i<len; ++i)*
  _ Serial.print(i<slen ? str : ' ');
  * feedgps();
  }
  static bool feedgps()
  {
  while (Serial.available())
  {
  if (gps.encode(Serial.read()))
  return true;
  }
  return false;
  }*
  Thanks in Advance!_