Arduino GPS – Adafruit Ultimate GPS Coordinates and Speed Display on LCD

This project uses the Adafruit Ultimate GPS Module, an Arduino Uno with WiFi and a 20×4 I2C LCD Screen to display your location in Degrees and show your speed of travel.


  • When I did this project with a standard Arduino Uno the Latitude was off by hundreds of miles, switching to an Arduino Uno with WiFi “magically” fixed the issue.
  • Make sure to solder on the battery holder and add the battery to the GPS. Initialization time for GPS goes from minutes without the battery to seconds with it.
    • (GPS.latitudeDegrees, 8)
    • (GPS.longitudeDegrees, 8)
  • In the code I display coordinates in Degrees which is compatible with Google Maps and standard mapping software.
  • When modifying Examples by Adafruit look for the ones that say “GPS_SoftwareSerial…”
  • Remember that the GPS may not pick up a single inside a building. On my ground floor the GPS works fine, but in my basement lab it receives no signals.

Prerequisite Classes:


Functional Parts in the Project:

//This is a modification of the Example code: GPS_SoftwareSerial_Parsing
//Works well with an Arduino Uno with WiFi Rev2, 
//with Arduino Uno I get massive Latitude Issues

#include <Adafruit_GPS.h>
#include <SoftwareSerial.h>

//ETCG Notes - LCD I2C Screen
#include <Wire.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,2,1,0,4,5,6,7);

// Connect the GPS Power pin to 5V
// Connect the GPS Ground pin to ground
// Connect the GPS TX (transmit) pin to Digital 8
// Connect the GPS RX (receive) pin to Digital 7

// you can change the pin numbers to match your wiring:
SoftwareSerial mySerial(8, 7);
Adafruit_GPS GPS(&mySerial);

// Set GPSECHO to 'false' to turn off echoing the GPS data to the Serial console
// Set to 'true' if you want to debug and listen to the raw GPS sentences
#define GPSECHO  true

void setup()

//ETCG Notes - Start LCD
   lcd.print("Arduino GPS");
  // connect at 115200 so we can read the GPS fast enough and echo without dropping chars
  // also spit it out
  Serial.println("Adafruit GPS library basic test!");
  // 9600 NMEA is the default baud rate for Adafruit MTK GPS's- some use 4800

  // uncomment this line to turn on RMC (recommended minimum) and GGA (fix data) including altitude
  // uncomment this line to turn on only the "minimum recommended" data
  // For parsing data, we don't suggest using anything but either RMC only or RMC+GGA since
  // the parser doesn't care about other sentences at this time

  // Set the update rate
  GPS.sendCommand(PMTK_SET_NMEA_UPDATE_1HZ);   // 1 Hz update rate
  // For the parsing code to work nicely and have time to sort thru the data, and
  // print it out we don't suggest using anything higher than 1 Hz

  // Request updates on antenna status, comment out to keep quiet

  // Ask for firmware version


uint32_t timer = millis();
void loop()                     // run over and over again
  char c =;
  // if you want to debug, this is a good time to do it!
  if ((c) && (GPSECHO))

  // if a sentence is received, we can check the checksum, parse it...
  if (GPS.newNMEAreceived()) {
    // a tricky thing here is if we print the NMEA sentence, or data
    // we end up not listening and catching other sentences!
    // so be very wary if using OUTPUT_ALLDATA and trytng to print out data
    //Serial.println(GPS.lastNMEA());   // this also sets the newNMEAreceived() flag to false

    if (!GPS.parse(GPS.lastNMEA()))   // this also sets the newNMEAreceived() flag to false
      return;  // we can fail to parse a sentence in which case we should just wait for another

  // approximately every 2 seconds or so, print out the current stats
  if (millis() - timer > 2000) {
    timer = millis(); // reset the timer

    Serial.print("\nTime: ");
    if (GPS.hour < 10) { Serial.print('0'); }
    Serial.print(GPS.hour, DEC); Serial.print(':');
    if (GPS.minute < 10) { Serial.print('0'); }
    Serial.print(GPS.minute, DEC); Serial.print(':');
    if (GPS.seconds < 10) { Serial.print('0'); }
    Serial.print(GPS.seconds, DEC); Serial.print('.');
    if (GPS.milliseconds < 10) {
    } else if (GPS.milliseconds > 9 && GPS.milliseconds < 100) {
    Serial.print("Date: ");
    Serial.print(, DEC); Serial.print('/');
    Serial.print(GPS.month, DEC); Serial.print("/20");
    Serial.println(GPS.year, DEC);
    Serial.print("Fix: "); Serial.print((int)GPS.fix);
    Serial.print(" quality: "); Serial.println((int)GPS.fixquality);
    if (GPS.fix) {
      Serial.print("Location: ");
      Serial.print(GPS.latitude, 8); Serial.print(;
      Serial.print(", ");
      Serial.print(GPS.longitude, 8); Serial.println(GPS.lon);
      //ETCG Notes -- The Following Gives Coordinates in formant you can plug into
      //Google Maps (Degrees)
      Serial.println("Location in Degrees");
      Serial.print(GPS.latitudeDegrees, 8);
      Serial.print(", ");
      Serial.println(GPS.longitudeDegrees, 8);

      Serial.print("Speed (knots): "); Serial.println(GPS.speed);
      Serial.print("Angle: "); Serial.println(GPS.angle);
      Serial.print("Altitude: "); Serial.println(GPS.altitude);
      Serial.print("Satellites: "); Serial.println((int)GPS.satellites);

      //ETCG Notes -- Print to LCD Screen
      lcd.print("Spd: ");
      float mph;
      mph = (GPS.speed) * 1.15;
      lcd.print("Lat: ");
      lcd.print(GPS.latitudeDegrees, 8);
      lcd.print("Lon: ");
      lcd.print(GPS.longitudeDegrees, 8);
    } else {
      lcd.print("No Signal");
    lcd.print("Satellites: ");


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