GPS Data logger for google map
Video
Code
Video
Hard ware
SD card to Arduino connect
CS >> 4
SCK >> 13
MOSI >> 11
MISO >> 12
VCC >> 5V
GND >> GND
GPS
TX >> 2
RX >> 3
VCC >> 3.3 V
Code
#include <SoftwareSerial.h> #include <SPI.h> #include <SD.h> File dataFile; SoftwareSerial GPSModule(2, 3); // RX, TX // process and flow related variables int updates; int failedUpdates; int pos; int stringplace = 0; // // variable to hold out nmea data and labels. String nmea[12]; String labels[12] {"Time: ", "Lat: ", "N/S: ", "Lng: ", "E/W: ", "Fix: ", "Sats: ", "HDP: ", "Alt: ", "Metres: ", "MSL: ", "Metres: "}; // void setup() { Serial.begin(9600); GPSModule.begin(9600); if (!SD.begin(4)) { Serial.println("failed"); // don't do anything more } else{ Serial.println("ok"); } } void loop() { dataFile = SD.open("gps.txt", FILE_WRITE); //flushing out data at the start of each loop, not sure it is really neccessay Serial.flush(); GPSModule.flush(); while (GPSModule.available() > 0) { GPSModule.read(); } // This is the meat of it really, we look for our nmea string and then split it into comma seperated values if (GPSModule.find("$GPGGA,")) { String tempMsg = GPSModule.readStringUntil('\n'); //Serial.println(tempMsg); for (int i = 0; i < tempMsg.length(); i++) { if (tempMsg.substring(i, i + 1) == ",") { nmea[pos] = tempMsg.substring(stringplace, i); stringplace = i + 1; pos++; } if (i == tempMsg.length() - 1) { nmea[pos] = tempMsg.substring(stringplace, i); } } updates++; // Here we convert our minutes and seconds latitute and longitute to decimal degrees nmea[1] = ConvertLat(); nmea[3] = ConvertLng(); // Test to see if GPS is fixed if(nmea[5].toInt() > 0){ // save data to SD if data is fixed if (dataFile) { Serial.println("writing"); // update number dataFile.print(updates); dataFile.print(","); // time dataFile.print(nmea[0]); dataFile.print(","); // latitude dataFile.print(nmea[1]); dataFile.print(","); // longitude dataFile.print(nmea[3]); dataFile.println(""); Serial.println("done"); } else{ Serial.println("error"); } } } else { failedUpdates++; Serial.println(failedUpdates); } // Print out data to the Serial Monitor for (int i = 0; i < 11; i++) { Serial.print(labels[i]); Serial.print(nmea[i]); Serial.println(""); } // Zero our flow control varibles stringplace = 0; pos = 0; // close file on SD card dataFile.close(); } // Here is the funky stuff - More details here https://www.youtube.com/watch?v=bgOZLgaLa0g String ConvertLat() { String posneg = ""; if (nmea[2] == "S") { posneg = "-"; } String latfirst; float latsecond; for (int i = 0; i < nmea[1].length(); i++) { if (nmea[1].substring(i, i + 1) == ".") { latfirst = nmea[1].substring(0, i - 2); latsecond = nmea[1].substring(i - 2).toFloat(); } } latsecond = latsecond / 60; String CalcLat = ""; char charVal[9]; dtostrf(latsecond, 4, 6, charVal); for (int i = 0; i < sizeof(charVal); i++) { CalcLat += charVal[i]; } latfirst += CalcLat.substring(1); latfirst = posneg += latfirst; return latfirst; } String ConvertLng() { String posneg = ""; if (nmea[4] == "W") { posneg = "-"; } String lngfirst; float lngsecond; for (int i = 0; i < nmea[3].length(); i++) { if (nmea[3].substring(i, i + 1) == ".") { lngfirst = nmea[3].substring(0, i - 2); //Serial.println(lngfirst); lngsecond = nmea[3].substring(i - 2).toFloat(); //Serial.println(lngsecond); } } lngsecond = lngsecond / 60; String CalcLng = ""; char charVal[9]; dtostrf(lngsecond, 4, 6, charVal); for (int i = 0; i < sizeof(charVal); i++) { CalcLng += charVal[i]; } lngfirst += CalcLng.substring(1); lngfirst = posneg += lngfirst; return lngfirst; }
