GPS Shield Hookup Guide

Introduction

The SparkFun GPS shield has several convenient features that make it easy to use GPS

modules with the Arduino Uno and SparkFun RedBoard (or any development board that

supports the Arduino shield form factor).

A GPS Shield sporting a UP501 GPS module, atop an Arduino Uno.

Assembly

Before use, you will need to solder headers to your shield. Take a look at the Shield

Assembly tutorial if you need a refresher. The GPS Shield uses the Uno R1 footprint

with 2x 8-pin and 2x 6-pin headers.

Required Materials

The GPS Shield Kit comes with the shield, headers, an EM-506 GPS module and foam

tape for attaching the module to the shield.

If you purchased the GPS shield separately, you will need to acquire a GPS Module of

your choice as well as the corresponding cables, headers or other connectors.

Suggested Reading

If you havent worked with GPS before, you may want to read the following tutorials before continuing with the GPS Shield.

GPS Basics - If youve always wanted to know how GPS works, this is the tutorial for you.

If youre not using Arduino or another microcontroller, you can still view the GPS modules serial output (and send commands to the GPS) using a terminal program.

Serial Communication

Serial Terminal Basics

Shield Overview

The top of the GPS shield:

and the bottom:

The SparkFun GPS Shield includes a 6-pin JST-SH socket (labeled EM406 on the top)

that fits both the EM-506 (included with the GPS shield kit) and its discontinued

predecessor the EM-406A as well as the the GP-635T. There are exposed pins and a

small prototyping area for use with other GPS modules. And there are unpopulated pads

for the 5-pin JST-SH connector found on the discontinued EM-408 module (labeled

EM408 on the top) .

The UART/DLINE switch connects the GPS modules serial lines to either Arduino hardware serial (D0/RX and D1/TX) or a user-selectable pair of software serial pins (D2

and D3 by default).

The closed solder jumpers marked Dselect 2 and 3 determine which pins are used in

DLINE mode.

ATMega328-based boards (like the Uno, Sparkfun RedBoard, and Sparkfun Pro Mini)

support change interrupts, a hardware function that's necessary for software serial, on

all digital pins. Arduino boards based on other chips (ATmega32u4, etc) have different

levels of support for change interrupts and software serial. A list of software-serial

compatible pins on various official Arduino boards is here.

The ON/OFF switch controls power to the GPS module. The RESET button connects

to the Arduino underneath.

On the back of the shield, there is an unpopulated 12mm coin cell battery holder

footprint for adding battery backup and warm start capabilities.

There is an additional unpopulated footprint for an 8-pin JST-SH connector as seen on

the discontinued 85A GPS module.

The BATT/3.3V jumper connects the VBAT lines on the unpopulated JST connectors

to either the (unpopulated) backup battery or to the Arduinos 3.3V line. 3.3V is selected by default.

Code Example

For this example, you will need to install the TinyGPSPlus library. Take a look at our

Arduino library install tutorial if youve never installed an Arduino library before.

Mikal Harts Arduiniana.org has a full overview of all of the capabilities of the TinyGPS++ library, but the most important one is parsing the GPS modules NMEA sentence output into latitude and longitude.

Press your completed Arduino shield (with headers soldered and your GPS plugged in

or soldered on) onto your Arduino, and connect your Arduino to your computer with

your USB cable.

Make sure your DLINE/UART switch is in the DLINE position every time you upload

a sketch, even if you're planning to use hardware serial. Having a GPS (or any other

serial device) connected during upload will cause the upload to fail. If you want to use

hardware serial, flip the switch back to UART after the upload finishes.

You will be using software serial for this example, so leave the switch in DLINE.

Upload the example sketch below to your Arduino.

#include

#include

/*

This example uses software serial and the TinyGPS++ library by Mikal

Hart

Based on TinyGPSPlus/DeviceExample.ino by Mikal Hart

Modified by acavis

*/

// Choose two Arduino pins to use for software serial

// The GPS Shield uses D2 and D3 by default when in DLINE mode

int RXPin = 2;

int TXPin = 3;

// The Skytaq EM-506 GPS module included in the GPS Shield Kit

// uses 4800 baud by default

int GPSBaud = 4800;

// Create a TinyGPS++ object called "gps"

TinyGPSPlus gps;

// Create a software serial port called "gpsSerial"

SoftwareSerial gpsSerial(RXPin, TXPin);

void setup()

{

// Start the Arduino hardware serial port at 9600 baud

Serial.begin(9600);

// Start the software serial port at the GPS's default baud

gpsSerial.begin(GPSBaud);

Serial.println(F("DeviceExample.ino"));

Serial.println(F("A simple demonstration of TinyGPS++ with an

attached GPS module"));

Serial.print(F("Testing TinyGPS++ library v. "));

Serial.println(TinyGPSPlus::libraryVersion());

Serial.println(F("by Mikal Hart"));

Serial.println();

}

void loop()

{

// This sketch displays information every time a new sentence is

correctly encoded.

while (gpsSerial.available() > 0)

if (gps.encode(gpsSerial.read()))

displayInfo();

// If 5000 milliseconds pass and there are no characters coming in

// over the software serial port, show a "No GPS detected" error

if (millis() > 5000 && gps.charsProcessed() < 10)

{

Serial.println(F("No GPS detected"));

while(true);

}

}

void displayInfo()

{

Serial.print(F("Location: "));

if (gps.location.isValid())

{

Serial.print(gps.location.lat(), 6);

Serial.print(F(","));

Serial.print(gps.location.lng(), 6);

}

else

{

Serial.print(F("INVALID"));

}

Serial.print(F(" Date/Time: "));

if (gps.date.isValid())

{

Serial.print(gps.date.month());

Serial.print(F("/"));

Serial.print(gps.date.day());

Serial.print(F("/"));

Serial.print(gps.date.year());

}

else

{

Serial.print(F("INVALID"));

}

Serial.print(F(" "));

if (gps.time.isValid())

{

if (gps.time.hour() < 10) Serial.print(F("0"));

Serial.print(gps.time.hour());

Serial.print(F(":"));

if (gps.time.minute() < 10) Serial.print(F("0"));

Serial.print(gps.time.minute());

Serial.print(F(":"));

if (gps.time.second() < 10) Serial.print(F("0"));

Serial.print(gps.time.second());

Serial.print(F("."));

if (gps.time.centisecond() < 10) Serial.print(F("0"));

Serial.print(gps.time.centisecond());

}

else

{

Serial.print(F("INVALID"));

}

Serial.println();

}