Getting started with Duinopeak GPS Logger Shield-Serial Streaming for NEO-M8N


A GPS-parsing Arduino libraries specifically for M8N are TinyGPSplus-for-Neo-M8N. These libraries simplify the task of parsing the excessive NMEA strings, leaving us with just the few bits of data we care about.

You need to install the libraries on your own Arduino development machine, visit the links above to download them. Reference sparkfun’s Installing an Arduino Librarytutorial for any additional library-installing help you may need.

TinyGPS++ Example for NEO-M8N only

Here’s a quick example, which uses the TinyGPS++ library to parse NMEA strings for position, altitude, time, and date. The code is also available in GPS Shield GitHub repository.

This example uses SoftwareSerial to communicate with the GPS module on
pins 8 and 9. It uses the TinyGPS++ library to parse the NMEA strings sent
by the GPS module, and prints interesting GPS information to the serial

After uploading the code, open your serial monitor, set it to 9600 baud, and
watch for latitude, longitude, altitude, course, speed, date, time, and the
number of visible satellites.

#include <TinyGPS++.h> // Include the TinyGPS++ library
TinyGPSPlus tinyGPS; // Create a TinyGPSPlus object

#define GPS_BAUD 9600 // GPS module baud rate. GP3906 defaults to 9600.

// If you’re using an Arduino Uno, Mega, RedBoard, or any board that uses the
// 0/1 UART for programming/Serial monitor-ing, use SoftwareSerial:
#include <SoftwareSerial.h>
#define ARDUINO_GPS_RX 3 // GPS TX, Arduino RX pin
#define ARDUINO_GPS_TX 2 // GPS RX, Arduino TX pin
SoftwareSerial ssGPS(ARDUINO_GPS_TX, ARDUINO_GPS_RX); // Create a SoftwareSerial

// Set gpsPort to either ssGPS if using SoftwareSerial or Serial1 if using an
// Arduino with a dedicated hardware serial port
#define gpsPort ssGPS  // Alternatively, use Serial1 on the Leonardo

// Define the serial monitor port. On the Uno, Mega, and Leonardo this is ‘Serial’
//  on other boards this may be ‘SerialUSB’
#define SerialMonitor Serial

void setup()

void loop()
// print position, altitude, speed, time/date, and satellites:

// “Smart delay” looks for GPS data while the Arduino’s not doing anything else

void printGPSInfo()
// Print latitude, longitude, altitude in feet, course, speed, date, time,
// and the number of visible satellites.
SerialMonitor.print(“Lat: “); SerialMonitor.println(, 6);
SerialMonitor.print(“Long: “); SerialMonitor.println(tinyGPS.location.lng(), 6);
SerialMonitor.print(“Alt: “); SerialMonitor.println(tinyGPS.altitude.feet());
SerialMonitor.print(“Course: “); SerialMonitor.println(tinyGPS.course.deg());
SerialMonitor.print(“Speed: “); SerialMonitor.println(tinyGPS.speed.mph());
SerialMonitor.print(“Date: “); printDate();
SerialMonitor.print(“Time: “); printTime();
SerialMonitor.print(“Sats: “); SerialMonitor.println(tinyGPS.satellites.value());

// This custom version of delay() ensures that the tinyGPS object
// is being “fed”. From the TinyGPS++ examples.
static void smartDelay(unsigned long ms)
unsigned long start = millis();
// If data has come in from the GPS module
while (gpsPort.available())
tinyGPS.encode(; // Send it to the encode function
// tinyGPS.encode(char) continues to “load” the tinGPS object with new
// data coming in from the GPS module. As full NMEA strings begin to come in
// the tinyGPS library will be able to start parsing them for pertinent info
} while (millis() – start < ms);

// printDate() formats the date into dd/mm/yy.
void printDate()

// printTime() formats the time into “hh:mm:ss”, and prints leading 0’s
// where they’re called for.
void printTime()
if (tinyGPS.time.minute() < 10) SerialMonitor.print(‘0’);
if (tinyGPS.time.second() < 10) SerialMonitor.print(‘0’);

You may need to adjust the gpsPort and SerialMonitor defines near the top of the sketch. As it is, the sketch is set up to use the SoftwareSerial port.

After uploading the code, open up your serial monitor to watch the parsed GPS data stream.

If your module doesn’t have a good GPS fix, you’ll probably see a lot of 0’s stream by; the time should be incrementing, although it’ll be incorrect (unless you plugged your Arduino in at exactly midnight!).

If you can find a way to take your computer and Arduino setup outside, that’ll be your best bet for getting a fix. Otherwise, try to take it near an open window. The better view it has of the sky, the better chance it’ll have to find the four satellites it needs.

A successful, fixed GPS stream will look something like this:

For more information on using the TinyGPS++ Library, check out the project homepage.

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