Arduino Fast GPS datalogger updated. Now with KML!

Now Updated (again) with selectable speed units, and configuration of U-blox GPS in runtime, avoiding the need to use U-Center to configure the receiver.  Click Here!

The fast GPS datalogger project is the most popular project on here. Link.

It's been working well on the race car since it's inception, and has provided some really useful data to improve the performance of the driver!

What isn't so great is how the data is stored. It stores everything, regardless of fix, number of races etc, so it's a headache to filter out each race, and remove useless invalid data, either without a time stamp or valid position or speed, and then turn it into something that could be used. I have been painstakingly converting the data into KML, which we can directly read with mapping software, such as Google Earth.

I've made some modifications to the software to sort out some of these issues... here's the new features:

Each time the record switch is pressed, valid GPS data is required, and once obtained, a new file name is created from the current time, HHMMSSCC.kml  (in UTC, CC representing centiseconds here), and the KML header file is written.

Now the file is built as in the previous version, except this time in KML format.

Speeds below 5 MPH are not recorded.

When record is switched off, the KML file is completed and closed.

So once the card is removed from the unit, simply read the kml file from the card, and open in google earth.

So I went out for a quick jaunt in England's green and pleasant....










... and loaded the KML file straight into google earth.

No more tedious editing required!

No changes to the hardware are required. Just remember to disconnect the RX line from the GPS module when attempting to load the new sketch.


Here's the code:

/* Fast GPS data logger. (c) 13th July 2016 A.G.Doswell License: The MIT License (See full license at the bottom of this file) The sketch uses a U-Blox 6M GPS satellite module connected to the hardware serial interface, a 128x64 SDD1306 OLED display module connected as an I2C device to pins A4 (SDA)& A5 (SCL) and an SD card interface connected to pins 4 (CS), 11 (MOSI), 12 (MISO) & 13 (SCK) The arduino used is a Nano with 3.3v ATMEGA328P. Warning - Many SD card interfaces are not 5V. There's a toggle switch which connects pin 9 to GND for Record. Data is written to the card an impressive 4 times per second, in real-time. The OzOled library is not quite "right" for this application, but works, and is lightweight and fast enough. Thanks Oscar! It is available here : http://blog.oscarliang.net/arduino-oled-display-library/ TinyGPSPlus is available here :https://github.com/mikalhart/TinyGPSPlus */ #include <SPI.h> #include <Wire.h> #include <OzOLED.h> #include <TinyGPS++.h> #include <SD.h> static const uint32_t GPSBaud = 57600; int SatVal; // Number of satellites locked int Speed; // Speed in MPH char SpeedA [4]; // Speed as char TinyGPSPlus gps; // Feed gps data to TinySGPSPlus File myFile; // Start SD int speedDigit; // Number of digits in Speedo display boolean card; // Is there a card present? boolean rec = false; // Is the record switch low? (false = high) int recPin = 9; // Record pin (Pull low to record data) boolean header = false; // Has the header been written? String filename ; // Concaternated filename +.kml String filename1 ; // Raw GPS Time filename. char fileNameChar [14]; // file name as char array void setup() { Serial.begin(GPSBaud); // Start GPS serial comms pinMode (recPin, INPUT_PULLUP); // recPin as input and pulled high OzOled.init(); // initialze SDD1306 OLED display OzOled.sendCommand(0x8d); // Set displays inbuilt inverter on OzOled.sendCommand(0x14); OzOled.setBrightness(0xFF); // ... and brightness to max OzOled.clearDisplay(); // Clear the screen OzOled.setNormalDisplay(); // Set display to Normal mode pinMode(10, OUTPUT); // CS for SD card, wether it likes it, or not. OzOled.clearDisplay(); if (!SD.begin(4)) { //Check SD card is present OzOled.printString("SD card fail ", 0, 7); card = false; } else { OzOled.printString("SD card OK ", 0, 7); card = true; } OzOled.printString("Sats:", 0, 0); // Set up display OzOled.printString("Speed:", 0, 1); OzOled.printString("MPH", 7, 6); } void loop() { while (Serial.available() > 0) //While GPS message received if (gps.encode(Serial.read())) displayInfo(); } void displayInfo() { // Display the data SatVal = int(gps.satellites.value()); Speed = int(gps.speed.mph()); itoa (Speed, SpeedA, 10); OzOled.printNumber ((long)SatVal, 6, 0); OzOled.printBigNumber (SpeedA, 7, 1); speedDigit = strlen(SpeedA); // get length of Speed , and delete left behind zero if req'd if (speedDigit == 1) OzOled.printBigNumber(" ", 10, 1); if (digitalRead(recPin) == HIGH && card == true) { //If the record switch is high and the card is OK, write card data, and update display if (header == false) { if (gps.date.year() > 2000 && gps.location.age() < 1500) { // makes sure we have (at some stage since power up) a valid time, and the current fix is valid.{ // if the header hasn't been written, create a new filename with current time HHMMSSCC.kml String filename1(gps.time.value()); String filename = filename1 + ".kml"; filename.toCharArray(fileNameChar, 13); } } OzOled.printString("SD card OK REC", 0, 7); } if (digitalRead(recPin) == LOW && card == true ) { // if record switch is off, set flag and update display OzOled.printString("SD card OK ", 0, 7); } if (digitalRead(recPin) == LOW && header == true) { // if record switch is off, but the header flag is set, write the footer. writeFooter(); } if (card == true && digitalRead(recPin) == HIGH && (gps.speed.mph() >= 5)) { writeInfo(); //write the data to the SD card } smartDelay(200); } // 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 (Serial.available()) gps.encode(Serial.read()); } while (millis() - start < ms); } void writeInfo() { //Write the data to the SD card fomratted for google earth kml myFile = SD.open(fileNameChar, FILE_WRITE); if (header == false) { // If the header hasn't been written, write it. if (myFile) { myFile.print(F("<?xml version=\"1.0\" encoding=\"UTF-8\"?> <kml xmlns=\"http://earth.google.com/kml/2.0\"> <document>")); header = true; // header flag set. } } if (myFile) { // write current GPS position data as KML myFile.println(F("<placemark>")); myFile.print(F("<name>")); myFile.print(gps.speed.mph(), 1); myFile.println(F("</name>")); myFile.print(F("<point><coordinates>")); myFile.print(gps.location.lng(), 6); myFile.print(F(",")); myFile.print(gps.location.lat(), 6); myFile.println(F("</coordinates></Point></Placemark>")); myFile.close(); // close the file: } } void writeFooter() { // if the record switch is now set to off, write the kml footer, and reset the header flag myFile = SD.open(fileNameChar, FILE_WRITE); header = false; if (myFile) { myFile.println(F("</Document>")); myFile.println (F("</kml>")); myFile.close (); } } /* Copyright (c) 2016 Andrew Doswell Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHOR(S) OR COPYRIGHT HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */