Itead GPS for Arduino , HELP!

Hello ,

I am trying to get my new GPS shield to work . It is the itead GPS v1.1 shield. The problem I am having is that I cannot log the data to the SD card slot built onto the board. I have searched the forums for countless hours and found a few code examples but none that seem to work for data logging.

I would like to save the file as a .csv file so that I can map my location using google maps. This requires comma separated strings I believe

The tutorial code is written for the Arduino Mega. I have tried this exactly as the tutorial explained but I believe the shield is setup differently. I did follow the data sheet and cross referenced it with the one in the video but no luck!

I am using an Ardunio uno , although I have many other boards available. I do not prefer one or the other for this job.

This is the code that does work on the Uno , but I cannot seem to add the SD card logging so I left it out..

#include <TinyGPS.h>

TinyGPS gps;

static void gpsdump(TinyGPS &gps);
static bool feedgps();
static void print_float(float val, float invalid, int len, int prec);
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.begin(9600);
  
  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);
}

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);
  print_float(flon, TinyGPS::GPS_INVALID_F_ANGLE, 10, 5);
  print_int(age, TinyGPS::GPS_INVALID_AGE, 5);

  print_date(gps);

  print_float(gps.f_altitude(), TinyGPS::GPS_INVALID_F_ALTITUDE, 8, 2);
  print_float(gps.f_course(), TinyGPS::GPS_INVALID_F_ANGLE, 7, 2);
  print_float(gps.f_speed_kmph(), TinyGPS::GPS_INVALID_F_SPEED, 6, 2);
  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);
  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[i] = ' ';
  if (len > 0) 
    sz[len-1] = ' ';
  Serial.print(sz);
  feedgps();
}

static void print_float(float val, float invalid, int len, int prec)
{
  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[i] = ' ';
    Serial.print(sz);
  }
  else
  {
    Serial.print(val, prec);
    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("*******    *******    ");
  else
  {
    char sz[32];
    sprintf(sz, "%02d/%02d/%02d %02d:%02d:%02d   ",
        month, day, year, hour, minute, second);
    Serial.print(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[i] : ' ');
  feedgps();
}

static bool feedgps()
{
  while (Serial.available())
  {
    if (gps.encode(Serial.read()))
      return true;
  }
  return false;
}

This is my attempt at data logging using the code above...Sorry for no comments , I really should start doing that ! :blush:

I used SoftwareSerial because I had some luck using the Uno and thought it might work better than my Mega 2650...Otherwise I would just use hardware

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



TinyGPS gps;


SoftwareSerial nss(6, 7);

static char dtostrfbuffer[20];
int LED = 13;
int LED2 = 5;
String SD_date_time = "invalid";
String SD_lat = "invalid";
String SD_lon = "invalid";
String dataString ="";


const int chipSelect = 10;
static void gpsdump(TinyGPS &gps);
static bool feedgps();
static void print_float(float val, float invalid, int len, int prec);
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.begin(9600);
  nss.begin(4800);
  
  


  if(!SD.begin(chipSelect))
  {
    Serial.println("Card Failure");
    return;
  }
  pinMode(10, OUTPUT);
  
  
  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);
  
  dataString = SD_date_time + "," + SD_lat + "," + SD_lon;
  if(SD_lat != "invalid")
    digitalWrite(LED, HIGH);

  else
    digitalWrite(LED2, HIGH);
    
    
    
  //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);
  print_float(flon, TinyGPS::GPS_INVALID_F_ANGLE, 10, 5);
  print_int(age, TinyGPS::GPS_INVALID_AGE, 5);

  print_date(gps);

  print_float(gps.f_altitude(), TinyGPS::GPS_INVALID_F_ALTITUDE, 8, 2);
  print_float(gps.f_course(), TinyGPS::GPS_INVALID_F_ANGLE, 7, 2);
  print_float(gps.f_speed_kmph(), TinyGPS::GPS_INVALID_F_SPEED, 6, 2);
  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);
  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[i] = ' ';
  if (len > 0) 
    sz[len-1] = ' ';
  Serial.print(sz);
  feedgps();
}

static void print_float(float val, float invalid, int len, int prec)
{
  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[i] = ' ';
    Serial.print(sz);
  }
  else
  {
    Serial.print(val, prec);
    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("*******    *******    ");
  else
  {
    char sz[32];
    sprintf(sz, "%02d/%02d/%02d %02d:%02d:%02d   ",
        month, day, year, hour, minute, second);
    Serial.print(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[i] : ' ');
  feedgps();
}

static bool feedgps()
{
  while (Serial.available())
  {
    if (gps.encode(Serial.read()))
      return true;
  }
  return false;
}

I also had difficulties getting SD logger to work. It is all to do with pin allocation and conflicts. I got two routines going and have copied here as it may help you::

/*
SD card datalogger

This example shows how to log data from three analog sensors
to an SD card using the SD library.

The circuit:

  • SD card attached to SPI bus as follows:
    ** UNO: MOSI - pin 11, MISO - pin 12, CLK - pin 13, CS - pin 4 (CS pin can be changed)
    and pin #10 (SS) must be an output
    ** Mega: MOSI - pin 51, MISO - pin 50, CLK - pin 52, CS - pin 4 (CS pin can be changed)
    and pin #52 (SS) must be an output
    ** Leonardo: Connect to hardware SPI via the ICSP header
    Pin 4 used here for consistency with other Arduino examples

created 24 Nov 2010
modified 9 Apr 2012 by Tom Igoe

This example code is in the public domain.

*/

#include <SD.h>

// On the Ethernet Shield, CS is pin 4. Note that even if it's not
// used as the CS pin, the hardware CS pin (10 on most Arduino boards,
// 53 on the Mega) must be left as an output or the SD library
// functions will not work.
const int chipSelect = 4;

File dataFile;

void setup()
{
// Open serial communications and wait for port to open:
Serial.begin(115200);
while (!Serial) {
; // wait for serial port to connect. Needed for Leonardo only
}

Serial.print("Initializing SD card...");
// make sure that the default chip select pin is set to
// output, even if you don't use it:
pinMode(SS, OUTPUT);
pinMode(52, OUTPUT); //For MEGA pin 52 MUST be defined as OUTPUT***
// see if the card is present and can be initialized:
if (!SD.begin(10,11,12,13)) {
Serial.println("Card failed, or not present");
// don't do anything more:
while (1) ;
}
Serial.println("card initialized.");

// Open up the file we're going to log to!
dataFile = SD.open("LOG.csv", FILE_WRITE);
if (! dataFile) {
Serial.println("error opening LOG.csv");
// Wait forever since we cant write data
while (1) ;
}
}

void loop()
{
// make a string for assembling the data to log:
String dataString = "";

// read three sensors and append to the string:
for (int analogPin = 0; analogPin < 3; analogPin++) {
int sensor = analogRead(analogPin);
dataString += String(sensor);
if (analogPin < 2) {
dataString += ",";
}
}

dataFile.println(dataString);

// print to the serial port too:
Serial.println(dataString);

// The following line will 'save' the file to the SD card after every
// line of data - this will use more power and slow down how much data
// you can read but it's safer!
// If you want to speed up the system, remove the call to flush() and it
// will save the file only every 512 bytes - every time a sector on the
// SD card is filled with data.
dataFile.flush();

// Take 1 measurement every 500 milliseconds
delay(500);
}

I am using MEGA 2560 so not sure it would work without change on DUO.
Hope it helps.
Mike

This is the Blum version
/

/Jeremy Blum's Arduino Tutorial Series - Episode 15 - GPS Tracking
//Sample Code 2 - Logging GPS Data to an SD Card
//http://www.jeremyblum.com
//TinyGPS Library and Helper Functions by Mikal Hart TinyGPS | Arduiniana

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

/* This sample code demonstrates the normal use of a TinyGPS object.
It uses an Arduino Mega with a GPS attached to Serial3 at 4800 buad.
*/

TinyGPS gps;
static char dtostrfbuffer[20];
int CS = 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()
{
pinMode(CS, OUTPUT); //Chip Select Pin for the SD Card
pinMode(LED, OUTPUT); //LED Indicator

//Serial interfaces
Serial.begin(115200);
Serial3.begin(9600);
//Select all
if (!SD.begin(10,11,12,13))
//Connect to the SD Card
if(!SD.begin(CS))
{
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 Kapiti ---- RX RX Fail");
Serial.println("--------------------------------------------------------------------------------------------------------------------------------------");
}

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

// Every second we print an update
while (millis() - start < 10000)
{
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 Kapiti_lat = -40.859328, Kapiti_lon = 174.927378;

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, 10, 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, Kapiti_lat, Kapiti_lon) / 1000, 0xFFFFFFFF, 9);
print_float(flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : TinyGPS::course_to(flat, flon, -40.859328, 174.927378), TinyGPS::GPS_INVALID_F_ANGLE, 7, 2, 0);
print_str(flat == TinyGPS::GPS_INVALID_F_ANGLE ? "*** " : TinyGPS::cardinal(TinyGPS::course_to(flat, flon, Kapiti_lat, Kapiti_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 (Serial3.available())
    {
    if (gps.encode(Serial3.read()))
    return true;
    }
    return false;
    }*_

Thanks for the reply Mike!

I have been up for hours trying to get this working so any help is good help , however I get a bunch of errors.

sketch_oct04a.ino: In function 'void setup()':
sketch_oct04a:48: error: no matching function for call to 'SDClass::begin(int, int, int, int)'
/Users/jcbhltz/Documents/Arduino.app/Contents/Resources/Java/libraries/SD/SD.h:69: note: candidates are: boolean SDClass::begin(uint8_t)
main.ino: In function 'void setup()':
main:28: error: redefinition of 'void setup()'
sketch_oct04a:33: error: 'void setup()' previously defined here
main:35: error: 'Serial3' was not declared in this scope
main:37: error: no matching function for call to 'SDClass::begin(int, int, int, int)'
/Users/jcbhltz/Documents/Arduino.app/Contents/Resources/Java/libraries/SD/SD.h:69: note: candidates are: boolean SDClass::begin(uint8_t)
main.ino: In function 'void loop()':
main:56: error: redefinition of 'void loop()'
sketch_oct04a:64: error: 'void loop()' previously defined here
main.ino: In function 'void print_int(long unsigned int, long unsigned int, int)':
main:131: error: incompatible types in assignment of 'char' to 'char [32]'
main.ino: In function 'void print_float(float, float, int, int, int)':
main:148: error: incompatible types in assignment of 'char' to 'char [32]'
main.ino: In function 'void print_str(const char*, int)':
main:194: error: operands to ?: have different types 'const char*' and 'char'
main.ino: In function 'bool feedgps()':
main:200: error: 'Serial3' was not declared in this scope

I may be completely over tired and not noticing the less obvious fixes. Please let me know if you got any of these errors and how you fixed them.

Thanks again!

Also , besides from the obvious fixes...There seems to be one that I must question before I 'fix'. The 9600 baud rate seems too high for GPS , isn't the shield supposed to operate at 4800 baud only?

I think I just needed the SD mega library. Will test it now , compiled fine besides a few errors

sz = ' ' ;

should have been , I think

sz = '' ;

It compiles and is sending data to the Mega. It is sending small amounts of data ..less than half as it does in the other sketch. It has not found any satellites yet , but is outputting via serial EXTREMELY slow ..seems like something in the code is slowing this down a lot .

EDIT:::

// Every second we print an update
while (millis() - start < 10000)
{
if (feedgps())
newdata = true;

this is not 1 second !!!

This is the code I have now..

//Jeremy Blum's Arduino Tutorial Series - Episode 15 - GPS Tracking
//Sample Code 2 - Logging GPS Data to an SD Card
//http://www.jeremyblum.com
//TinyGPS Library and Helper Functions by Mikal Hart http://arduiniana.org/libraries/tinygps/


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

/* This sample code demonstrates the normal use of a TinyGPS object.
   It uses an Arduino Mega with a GPS attached to Serial3 at 4800 buad.
*/

TinyGPS gps;
static char dtostrfbuffer[20];
int CS = 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()
{
  pinMode(CS, OUTPUT);  //Chip Select Pin for the SD Card
  pinMode(LED, OUTPUT);  //LED Indicator
  
  //Serial interfaces
  Serial.begin(115200);
  Serial3.begin(4800);
  
  //Connect to the SD Card
   if (!SD.begin(10,11,12,13))
  {
    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[i] = ' ';
  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[i] = ' ';
    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[i] : ' ');
  feedgps();
}

static bool feedgps()
{
  while (Serial3.available())
  {
    if (gps.encode(Serial3.read()))
      return true;
  }
  return false;
}

my output is very small amounts of char data...Its supposed to be 10x more at least

Testing TinyGPS library v. 13
by Mikal Hart

Sizeof(gpsobject) = 115

Sats HDOP Latitude Longitude Fix Date Time Date Alt Course Speed Card Distance Course Card Chars Sentences Checksum
(deg) (deg) Age Age (m) --- from GPS ---- ---- to London ---- RX RX Fail

**** **** ******* ******* **** ******* ******* **** ******* ****** ***** *** 0 0.00 *** 19 0 0
invalid,******* ,*******
**** **** ******* ******* **** ******* ******* **** ******* ****** ***** *** 0 0.00 *** 26 0 0
invalid,******* ,*******
**** **** ******* ******* **** ******* ******* **** ******* ****** ***** *** 0 0.00 *** 34 0 0
invalid,******* ,*******
**** **** ******* ******* **** ******* ******* **** ******* ****** ***** *** 0 0.00 *** 41 0 0
invalid,******* ,*******
**** **** ******* ******* **** ******* ******* **** ******* ****** ***** *** 0 0.00 *** 48 0 0
invalid,******* ,*******
**** **** ******* ******* **** ******* ******* **** ******* ****** ***** *** 0 0.00 *** 54 0 0
invalid,******* ,*******
**** **** ******* ******* **** ******* ******* **** ******* ****** ***** *** 0 0.00 *** 62 0 0
invalid,******* ,*******

notice it is growing incrementally 7-8

Although the TinyGPS library works great, the example that comes with it is crap.

Do NOT dump the GPS data every pass through loop(). No not log to the card every pass through loop. Do not read data for one second at a time.

This is all that should be in loop():

    if (feedgps())
    {
       // print the data
       // log the data
    }

(With valid code to replace the comments, of course).

Hey PaulS ,

I was really hoping you would reply to this post , you seem to help everyone with there GPS!

This is my code right now , I will add the changes that you have posted. I get data from the GPS shield but I get quite a few checksum errors which , from my understanding , are just ignored. The shield does now log the data but I left it in an open area for 2 hours today and did not get any non-invalid data.

I know the shield and wiring are correct because I used other code without data logging and It worked great , but only able to view VIA the serial terminal.

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

SoftwareSerial newserial(2, 3);

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


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()
{
  pinMode(10, OUTPUT); 
  pinMode(LED, OUTPUT);  
  
  //Serial interfaces
  Serial.begin(57600);
  newserial.begin(9600);
  

  if(!SD.begin(10))
  {
    Serial.println("Card Failure");
    return;
  }
  
  
   Serial.println(TinyGPS::library_version());

  Serial.println();
  Serial.print("Sizeof(gpsobject) = "); Serial.println(sizeof(TinyGPS));
  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); 
  print_float(flon, TinyGPS::GPS_INVALID_F_ANGLE, 10, 5, 2);
  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[i] = ' ';
  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[i] = ' ';
    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[i] : ' ');
  feedgps();
}

static bool feedgps()
{
  while (newserial.available())
  {
    if (gps.encode(newserial.read()))
      return true;
  }
  return false;
}