SDGPSLogger

The SD GPS logger will take data from a GPS and log it into a file on an SD card every 5 seconds.

It is based on the Arduino with an SD card shield and an attached GPS.

Here is the source code: /*

 SD gps datalogger
 
 This will log locations to a file on an SD card.

 Known bugs:
   If the code writes to the SD card at the same time you power down, it
   can corrupt the file system on the SD card.

 Pins:
   SD MOSI - pin 11
   SD CLK - pin 13
   SD CS - pin 8
   GPS serial out - pin 7
   GPS serial in - pin 6 (not needed)

 SD Shield:
   http://www.sparkfun.com/products/9802

 GPS:
   http://www.byonics.com/tinytrak/gps.php (GPS2)

 Required Libraries:
   NewSoftSerial - http://arduiniana.org/libraries/newsoftserial/
   TinyGPS - http://arduiniana.org/libraries/tinygps/

Copyright (C) 2011 Jay Sissom

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. THIS SOFTWARE IS RELEASED UNDER THE TERMS OF VERSION 2 OF THE GPL LICENSE ONLY.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

http://www.gnu.org/licenses/gpl-2.0.html

Jay Sissom jsissom@gmail.com

*/

1. include <SD.h>
2. include <NewSoftSerial.h>
3. include <TinyGPS.h>

// GPS and serial objects TinyGPS gps; NewSoftSerial nss(7,6,true);

// GPS data (global so we don't need to pass them around) long lat, lon; int year; byte month, day, hour, minute, second, hundredths; unsigned long age, date, time, chars, speed; bool moving = true;

// 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 = 8;

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.");

 nss.begin(4800);
 
 Serial.println("GPS initialized.");

}

void loop() {

 bool newdata = false;
 unsigned long start = millis();

 // Every 5 seconds we write an update (if we are moving)
 while (millis() - start < 5000) {
   if ( feedgps() ) {
     newdata = true;
   }
 }

 if (newdata) {
   speed = gps.speed();
   gps.get_position(&lat, &lon, &age);
   feedgps();
   gps.get_datetime(&date, &time, &age);
   feedgps();
   gps.crack_datetime(&year, &month, &day, &hour, &minute, &second, &hundredths, &age);
   feedgps();

   // Only write data if we are moving
   if ( moving ) {
     writeData();
   }
   moving = ( speed > 85 );
 } else {
   Serial.println("No GPS data during the last 5 seconds");
 }

}

bool feedgps() {

 while (nss.available()) {
   if (gps.encode(nss.read()))
     return true;
 }
 return false;

}

void writeData() {

 // 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) {
   feedgps();
   dataFile.print(lat);
   dataFile.print("\t");
   dataFile.print(lon);
   dataFile.print("\t");
   dataFile.print(gps.altitude());
   dataFile.print("\t");
   feedgps();
   dataFile.print(year);
   dataFile.print("\t");
   dataFile.print(static_cast<int>(month));
   dataFile.print("\t");
   dataFile.print(static_cast<int>(day));
   dataFile.print("\t");
   dataFile.print(static_cast<int>(hour));
   feedgps();
   dataFile.print("\t");
   dataFile.print(static_cast<int>(minute));
   dataFile.print("\t");
   dataFile.print(static_cast<int>(second));
   dataFile.print("\t");
   dataFile.print(gps.course());
   dataFile.print("\t");
   dataFile.print(speed);
   dataFile.print("\t");
   dataFile.println(age);
   feedgps();
   dataFile.close();
 } else {
   Serial.println("error opening datalog.txt");
 } 

 // print to the serial port too:
 feedgps();
 Serial.print(lat);
 Serial.print("\t");
 Serial.print(lon);
 Serial.print("\t");
 Serial.print(gps.altitude());
 Serial.print("\t");
 feedgps();
 Serial.print(year);
 Serial.print("\t");
 Serial.print(static_cast<int>(month));
 Serial.print("\t");
 Serial.print(static_cast<int>(day));
 Serial.print("\t");
 Serial.print(static_cast<int>(hour));
 feedgps();
 Serial.print("\t");
 Serial.print(static_cast<int>(minute));
 Serial.print("\t");
 Serial.print(static_cast<int>(second));
 Serial.print("\t");
 Serial.print(gps.course());
 Serial.print("\t");
 Serial.print(gps.speed());
 Serial.print("\t");
 Serial.println(age);
 feedgps();

}