Write Serial Monitor data to SD

Using Arduino Storage
1

Hello guys, i have a GPS system which logs the required data to serial port, how should i edit the code for it to log it to an SD card in the same format. The code so far is:

#include <TinyGPS++.h>
#include <SoftwareSerial.h>
/*
   This sample code demonstrates the normal use of a TinyGPS++ (TinyGPSPlus) object.
   It requires the use of SoftwareSerial, and assumes that you have a
   4800-baud serial GPS device hooked up on pins 4(rx) and 3(tx).
*/
static const int RXPin = 4, TXPin = 3;
static const uint32_t GPSBaud = 9600;

// The TinyGPS++ object
TinyGPSPlus gps;

// The serial connection to the GPS device
SoftwareSerial ss(RXPin, TXPin);

void setup()
{
  Serial.begin(9600);
  ss.begin(GPSBaud);

  ///Serial.println(F("FullExample.ino"));
  //Serial.println(F("An extensive example of many interesting TinyGPS++ features"));
  //Serial.print(F("Testing TinyGPS++ library v. ")); Serial.println(TinyGPSPlus::libraryVersion());
  //Serial.println(F("by Mikal Hart"));
  Serial.println();
  Serial.println(F("Latitude   Longitude   Date       Time     Date"));
  Serial.println(F("(deg)      (deg)                 (UTC+0)   Age"));
  Serial.println(F("---------------------------------------------------------------------------------------------------------------------------------------"));
}

void loop()
{
  static const double LONDON_LAT = 51.508131, LONDON_LON = -0.128002;

  //printInt(gps.satellites.value(), gps.satellites.isValid(), 5);
  //printInt(gps.hdop.value(), gps.hdop.isValid(), 5);
  printFloat(gps.location.lat(), gps.location.isValid(), 11, 6);
  printFloat(gps.location.lng(), gps.location.isValid(), 12, 6);
  //printInt(gps.location.age(), gps.location.isValid(), 5);
  printDateTime(gps.date, gps.time);
  //printFloat(gps.altitude.meters(), gps.altitude.isValid(), 7, 2);
  //printFloat(gps.course.deg(), gps.course.isValid(), 7, 2);
  //printFloat(gps.speed.kmph(), gps.speed.isValid(), 6, 2);
  //printStr(gps.course.isValid() ? TinyGPSPlus::cardinal(gps.course.value()) : "*** ", 6);

  unsigned long distanceKmToLondon =
    (unsigned long)TinyGPSPlus::distanceBetween(
      gps.location.lat(),
      gps.location.lng(),
      LONDON_LAT, 
      LONDON_LON) / 1000;
  //printInt(distanceKmToLondon, gps.location.isValid(), 9);

  double courseToLondon =
    TinyGPSPlus::courseTo(
      gps.location.lat(),
      gps.location.lng(),
      LONDON_LAT, 
      LONDON_LON);

  //printFloat(courseToLondon, gps.location.isValid(), 7, 2);

  const char *cardinalToLondon = TinyGPSPlus::cardinal(courseToLondon);

 // printStr(gps.location.isValid() ? cardinalToLondon : "*** ", 6);

  //printInt(gps.charsProcessed(), true, 6);
  //printInt(gps.sentencesWithFix(), true, 10);
  //printInt(gps.failedChecksum(), true, 9);
  Serial.println();
  
  smartDelay(1000);

  if (millis() > 5000 && gps.charsProcessed() < 10)
    Serial.println(F("No GPS data received: check wiring"));
}

// This custom version of delay() ensures that the gps object
// is being "fed".
static void smartDelay(unsigned long ms)
{
  unsigned long start = millis();
  do 
  {
    while (ss.available())
      gps.encode(ss.read());
  } while (millis() - start < ms);
}

static void printFloat(float val, bool valid, int len, int prec)
{
  if (!valid)
  {
    while (len-- > 1)
      Serial.print('*');
    Serial.print(' ');
  }
  else
  {
    Serial.print(val, prec);
    int vi = abs((int)val);
    int flen = prec + (val < 0.0 ? 2 : 1); // . and -
    flen += vi >= 1000 ? 4 : vi >= 100 ? 3 : vi >= 10 ? 2 : 1;
    for (int i=flen; i<len; ++i)
      Serial.print(' ');
  }
  smartDelay(0);
}

static void printInt(unsigned long val, bool valid, int len)
{
  char sz[32] = "*****************";
  if (valid)
    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);
  smartDelay(0);
}

static void printDateTime(TinyGPSDate &d, TinyGPSTime &t)
{
  if (!d.isValid())
  {
    Serial.print(F("********** "));
  }
  else
  {
    char sz[32];
    sprintf(sz, "%02d/%02d/%02d ", d.month(), d.day(), d.year());
    Serial.print(sz);
  }
  
  if (!t.isValid())
  {
    Serial.print(F("******** "));
  }
  else
  {
    char sz[32];
    sprintf(sz, "%02d:%02d:%02d ", t.hour(), t.minute(), t.second());
    Serial.print(sz);
  }

  printInt(d.age(), d.isValid(), 5);
  smartDelay(0);
}

static void printStr(const char *str, int len)
{
  int slen = strlen(str);
  for (int i=0; i<len; ++i)
    Serial.print(i<slen ? str[i] : ' ');
  smartDelay(0);
}
2

how should i edit the code for it to log it to an SD card in the same format. The code so far is:

What are the steps involved? Open a file. Write some data. Close the file. Which step seems particularly challenging?

3

I've tried using the SD example to include it in the GPS one, yet i'm actually unsure of what i am doing.

#include <TinyGPS++.h>
#include <SoftwareSerial.h>
#include <SPI.h>
#include <SD.h>
/*
   GPS
   Rx from GPS to pin 2
   Tx from GPS to pin 3
   
   SD
   MOSI - pin 11
   MISO - pin 12
   CLK - pin 13
   CS - pin 4
*/
static const int RXPin = 3, TXPin = 2;
static const uint32_t GPSBaud = 9600;

// The TinyGPS++ object
TinyGPSPlus gps;

// The serial connection to the GPS device
SoftwareSerial ss(RXPin, TXPin);
//SD
// 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;

void setup()
{
  Serial.begin(9600);
  
    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(10, OUTPUT);

  // see if the card is present and can be initialized:
  if (!SD.begin(chipSelect)) {
    Serial.println("Card failed, or not present");
    // don't do anything more:
    return;
  }
  Serial.println("card initialized.");
  
  
  
  ss.begin(GPSBaud);

  ///Serial.println(F("FullExample.ino"));
  //Serial.println(F("An extensive example of many interesting TinyGPS++ features"));
  //Serial.print(F("Testing TinyGPS++ library v. ")); Serial.println(TinyGPSPlus::libraryVersion());
  //Serial.println(F("by Mikal Hart"));
  Serial.println();
  Serial.println(F("Latitude   Longitude   Date       Time     Date"));
  Serial.println(F("(deg)      (deg)                 (UTC+0)   Age"));
  Serial.println(F("---------------------------------------------------------------------------------------------------------------------------------------"));
}

void loop()
{
  // open the file. note that only one file can be open at a time,
  // so you have to close this one before opening another.
  File dataFile = SD.open("datalog.txt", FILE_WRITE);

  // if the file is available, write to it:
  if (dataFile) {
    dataFile.println(dataString);
    //dataFile.close();
    // print to the serial port too:
    Serial.println(dataString);
  }
  // if the file isn't open, pop up an error:
  else {
    Serial.println("error opening datalog.txt");
  }
  
  
  
  
  
  static const double LONDON_LAT = 51.508131, LONDON_LON = -0.128002;

  //printInt(gps.satellites.value(), gps.satellites.isValid(), 5);
  //printInt(gps.hdop.value(), gps.hdop.isValid(), 5);
  printFloat(gps.location.lat(), gps.location.isValid(), 11, 6);
  printFloat(gps.location.lng(), gps.location.isValid(), 12, 6);
  //printInt(gps.location.age(), gps.location.isValid(), 5);
  printDateTime(gps.date, gps.time);
  //printFloat(gps.altitude.meters(), gps.altitude.isValid(), 7, 2);
  //printFloat(gps.course.deg(), gps.course.isValid(), 7, 2);
  //printFloat(gps.speed.kmph(), gps.speed.isValid(), 6, 2);
  //printStr(gps.course.isValid() ? TinyGPSPlus::cardinal(gps.course.value()) : "*** ", 6);

  unsigned long distanceKmToLondon =
    (unsigned long)TinyGPSPlus::distanceBetween(
      gps.location.lat(),
      gps.location.lng(),
      LONDON_LAT, 
      LONDON_LON) / 1000;
  //printInt(distanceKmToLondon, gps.location.isValid(), 9);

  double courseToLondon =
    TinyGPSPlus::courseTo(
      gps.location.lat(),
      gps.location.lng(),
      LONDON_LAT, 
      LONDON_LON);

  //printFloat(courseToLondon, gps.location.isValid(), 7, 2);

  const char *cardinalToLondon = TinyGPSPlus::cardinal(courseToLondon);

 // printStr(gps.location.isValid() ? cardinalToLondon : "*** ", 6);

  //printInt(gps.charsProcessed(), true, 6);
  //printInt(gps.sentencesWithFix(), true, 10);
  //printInt(gps.failedChecksum(), true, 9);
  Serial.println();
  
  smartDelay(1000);

  if (millis() > 5000 && gps.charsProcessed() < 10)
    Serial.println(F("No GPS data received: check wiring"));
}

// This custom version of delay() ensures that the gps object
// is being "fed".
static void smartDelay(unsigned long ms)
{
  unsigned long start = millis();
  do 
  {
    while (ss.available())
      gps.encode(ss.read());
  } while (millis() - start < ms);
}

static void printFloat(float val, bool valid, int len, int prec)
{
  if (!valid)
  {
    while (len-- > 1)
      Serial.print('*');
    Serial.print(' ');
  }
  else
  {
    Serial.print(val, prec);
    int vi = abs((int)val);
    int flen = prec + (val < 0.0 ? 2 : 1); // . and -
    flen += vi >= 1000 ? 4 : vi >= 100 ? 3 : vi >= 10 ? 2 : 1;
    for (int i=flen; i<len; ++i)
      Serial.print(' ');
  }
  smartDelay(0);
}

static void printInt(unsigned long val, bool valid, int len)
{
  char sz[32] = "*****************";
  if (valid)
    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);
  smartDelay(0);
}

static void printDateTime(TinyGPSDate &d, TinyGPSTime &t)
{
  if (!d.isValid())
  {
    Serial.print(F("********** "));
  }
  else
  {
    char sz[32];
    sprintf(sz, "%02d/%02d/%02d ", d.month(), d.day(), d.year());
    Serial.print(sz);
  }
  
  if (!t.isValid())
  {
    Serial.print(F("******** "));
  }
  else
  {
    char sz[32];
    sprintf(sz, "%02d:%02d:%02d ", t.hour(), t.minute(), t.second());
    Serial.print(sz);
  }

  printInt(d.age(), d.isValid(), 5);
  smartDelay(0);
}

static void printStr(const char *str, int len)
{
  int slen = strlen(str);
  for (int i=0; i<len; ++i)
    Serial.print(i<slen ? str[i] : ' ');
  smartDelay(0);
}

How do i make it print the same thing on the SD. In the SD example it has a string (dataString) which i guess needs to be change to my data, how do i do that? And will it create the file automatically?

Serial MonitOr.png
Serial MonitOr.png1023×738 64.8 KB

4

Perhaps look at an OpenLog? This will log serial data to an SD card without any programming.

5

Thanks for replying. Did you mean this product? OpenLog

If YES, well i actually am on a tight schedule for the project, buying it now is not an option as shipping would take a month at minimum. :S

6

In the SD example it has a string (dataString) which i guess needs to be change to my data

That code is crap.

dataFile is an instance of File derives from Stream which derives from Print.
Serial is an instance of HardwareSerial which derives from Stream which derives from Print.

So, Serial.print() and dataFile.print() call the EXACT same function. Whatever you print with Serial.print() can be written to the card with dataFile.print(), by simply changing the instance name.
smartDelay() is a delay. It is NOT the proper way to read GPS data.

7

It is strange, I'm trying to save incoming data to sd card coming in from serial.read but not sure if to read char or byte from serial.read or to write byte or char to sd card.

I'm trying to find a way to do binary data transfer while making dynamic filenames to use for sd card.

I managed to create a sort of hexadecimal based filename scheme to allow for 0xFFFFFFFF files on it.
Not sure if Fat32 can handle that. If I'm using FAT32, Should I be writing Longs to the sd card for 32 bits at a time?