Tag Archives: Adafruit Ultimate GPS

In this video lesson I show how to get usable Latitude and Longitude from the Adafruit Ultimate GPS version 3 using the Raspberry Pi Pico W. We read the NMEA sentences from the GPS, we parse them into individual strings for each sentence, and then we create arrays of data from the strings. Then we begin to parse the arrays, and convert the confusing numbers into useful Decimal Degree values for Latitude and Longitude.

Pi Pico GPS — This schematic shows how to connect the Adafruit Ultimate GPS to the Raspberry Pi Pico W

For your convenience, this is the code we developed in todays lesson:

from machine import Pin,I2C,UART  #***************
import time
GPS = UART(1, baudrate=9600, tx=machine.Pin(8), rx=machine.Pin(9))
myNMEA=""
GPGGA=""
GPGSA=""
GPRMC=""
GPVTG=""
GPGSV=""
while not GPS.any():
    pass
while GPS.any():
    junk=GPS.read()
    print(junk)
try:
    while True:
        if GPS.any():
            #myChar=GPS.read(1)
            myChar=GPS.read(1).decode('utf-8')
            myNMEA=myNMEA+myChar
            if myChar=='\n':
                if myNMEA[1:6]=="GPGGA":
                    GPGGA=myNMEA
                    GPGGAarray=GPGGA.split(',')
                    #print(GPGGA)
                    #print(GPGGAarray)
                    if int(GPGGAarray[6]) != 0:
                        latRAW=GPGGAarray[2]
                        lonRAW=GPGGAarray[4]
                        numSat=int(GPGGAarray[7])
                        latDD=int(latRAW[0:2])+float(latRAW[2:])/60
                        lonDD=int(lonRAW[0:3])+float(lonRAW[3:])/60
                        if GPGGAarray[3]=='S':
                            latDD=-latDD
                        if GPGGAarray[5]=='W':
                            lonDD=-lonDD
                        print("LAT, LON, numSat ",latDD,lonDD,numSat)
                if myNMEA[1:6]=="GPGSA":
                    GPGSA=myNMEA
                    GPGSAarray=GPGSA.split(',')
                if myNMEA[1:6]=="GPRMC":
                    GPRMC=myNMEA
                    GPRMCarray=GPRMC.split(',')
                    knots=float(GPRMCarray[7])
                    heading=float(GPRMCarray[8])
                    print(knots, "Knots at a Heading of: ",heading)
                if myNMEA[1:6]=="GPVTG":
                    GPVTG=myNMEA
                    GPVTGarray=GPVTG.split(',')
                if myNMEA[1:6]=="GPGSV":
                    GPGSV=myNMEA
                    GPGSVarray=GPGSV.split(',')
                    if GPGGA!="":
                        if int(GPGGAarray[6])==0:
                            print('Aquiring Fix:', GPGSVarray[3], "Sattellites in View")
                                              
                myNMEA=""
except KeyboardInterrupt:
    print("\nStopping program... Cleaning up UART.")
    GPS.deinit()  # Properly release UART before exit
    time.sleep(1)  # Short pause to ensure clean shutdown
    print("Exited cleanly.")

from machine import Pin,I2C,UART #***************

import time

GPS = UART(1, baudrate=9600, tx=machine.Pin(8), rx=machine.Pin(9))

myNMEA=""

GPGGA=""

GPGSA=""

GPRMC=""

GPVTG=""

GPGSV=""

while not GPS.any():

pass

while GPS.any():

junk=GPS.read()

print(junk)

try:

while True:

if GPS.any():

#myChar=GPS.read(1)

myChar=GPS.read(1).decode('utf-8')

myNMEA=myNMEA+myChar

if myChar=='\n':

if myNMEA[1:6]=="GPGGA":

GPGGA=myNMEA

GPGGAarray=GPGGA.split(',')

#print(GPGGA)

#print(GPGGAarray)

if int(GPGGAarray[6]) != 0:

latRAW=GPGGAarray[2]

lonRAW=GPGGAarray[4]

numSat=int(GPGGAarray[7])

latDD=int(latRAW[0:2])+float(latRAW[2:])/60

lonDD=int(lonRAW[0:3])+float(lonRAW[3:])/60

if GPGGAarray[3]=='S':

latDD=-latDD

if GPGGAarray[5]=='W':

lonDD=-lonDD

print("LAT, LON, numSat ",latDD,lonDD,numSat)

if myNMEA[1:6]=="GPGSA":

GPGSA=myNMEA

GPGSAarray=GPGSA.split(',')

if myNMEA[1:6]=="GPRMC":

GPRMC=myNMEA

GPRMCarray=GPRMC.split(',')

knots=float(GPRMCarray[7])

heading=float(GPRMCarray[8])

print(knots, "Knots at a Heading of: ",heading)

if myNMEA[1:6]=="GPVTG":

GPVTG=myNMEA

GPVTGarray=GPVTG.split(',')

if myNMEA[1:6]=="GPGSV":

GPGSV=myNMEA

GPGSVarray=GPGSV.split(',')

if GPGGA!="":

if int(GPGGAarray[6])==0:

print('Aquiring Fix:', GPGSVarray[3], "Sattellites in View")

myNMEA=""

except KeyboardInterrupt:

print("\nStopping program... Cleaning up UART.")

GPS.deinit() # Properly release UART before exit

time.sleep(1) # Short pause to ensure clean shutdown

print("Exited cleanly.")

MicroPython, Raspberry Pi Pico

Connecting the Adafruit Ultimate GPS to the Raspberry Pi Pico W

June 9, 2025 admin

In this video lesson we will connect the Adafruit Ultimate GPS to the Raspberry Pi Pico W, and will write a simple program to capture the data being sent by the GPS. In this lesson, we simply want to read and print the NMEA sentences coming off the GPS, and then in future lessons we will begin to parse the data, and turn the data into usable numbers. This is the schematic for connecting the GPS to your Raspberry Pi Pico W.

Then this is the simple code we developed to allow reading the data coming from the GPS.

from machine import Pin,I2C,UART  #***************
import time

GPS = UART(1, baudrate=9600, tx=machine.Pin(8), rx=machine.Pin(9))
try:
    while True:
        if GPS.any():
            #myChar=GPS.read(1)
            myChar=GPS.read(1).decode('utf-8')
            print(myChar, end="") #Supress the line feed, so It continues to print across
except KeyboardInterrupt:
    print("\nStopping program... Cleaning up UART.")
    GPS.deinit()  # Properly release UART before exit
    time.sleep(1)  # Short pause to ensure clean shutdown
    print("Exited cleanly.")

from machine import Pin,I2C,UART #***************

import time

GPS = UART(1, baudrate=9600, tx=machine.Pin(8), rx=machine.Pin(9))

try:

while True:

if GPS.any():

#myChar=GPS.read(1)

myChar=GPS.read(1).decode('utf-8')

print(myChar, end="") #Supress the line feed, so It continues to print across

except KeyboardInterrupt:

print("\nStopping program... Cleaning up UART.")

GPS.deinit() # Properly release UART before exit

time.sleep(1) # Short pause to ensure clean shutdown

print("Exited cleanly.")

Raspberry Pi Pico

Getting Geared Up for the Ultimate GPS Tracker with Raspberry Pi Pico W

May 22, 2025 admin

GPS Project — Gearing Up for the Ultimate GPS Challenge

Guys in this class we will be building the Ultimate GPS Tracker. This will build on all you learned in our most excellent Raspberry Pi Pico W class, and now we will begin working on a real project. Hopefully most of the gear you will already have from the various kits you already have, but I give amazon links to the gear we will be using in the project. You Will Need:

Raspberry Pi Pico W: ORDER HERE
Adafruit Ultimate GPS: ORDER HERE
External Antenna (OPTIONAL): ORDER HERE
Button Battery For Quicker Fix: ORDER HERE
Soldering Iron: ORDER HERE
Solder Practice Components: ORDER HERE
Extra Solder: ORDER HERE
Safety Glasses: ORDER HERE
Breadvolt Power Supply (OPTIONAL): ORDER HERE
Charging Cable (If You Don’t Have): ORDER HERE
OLED SSD1306: (ORDER HERE)
Breadboard and Wires (If You Don’t Have): ORDER HERE

Arduino, Tutorial

LESSON 30: Advanced Software Interrupt Techniques for Reading Serial Data with Arduino

March 21, 2018 admin

In Lesson 28 and Lesson 29 we showed how to use simple software interrupts to do quick and easy tasks like turning an LED on or off. We emphasized the importance of just doing simple tasks, and to get in and out of the interrupt function as quickly as possible. It is sometimes necessary to do more sophisticated functions. For example, the Adafruit Ultimate GPS immediately begins sending serial data on powerup. Making matters worse, it sends big bursts of data, and then waits, and then later sends bursts of data again. The data that is sent needs to not just be read, but you must parse the data to make sense of it. Hence, you end up needing to do sophisticated functions to parse the data, but at the same time you have to make sure you do not miss any of the new incoming data. This requires a more thoughtful and sophisticated interrupt strategy.

First off, we will need a better software interrupt library. You should erase the TimerOne library you installed in Lesson 28, and replace it with the one here:

https://github.com/PaulStoffregen/TimerOne

The video shows how to get the library if you are not familiar with github.

The video takes you through the code below. While this is done for the Adafruit GPS, this method should work for other sensors that spew serial data.

void loop(){

digitalWrite(RedLED,HIGH);
delay(1000);
digitalWrite(RedLED,LOW);
delay(1000);


 
if (flag==1){
 
  Timer1.stop();
  NMEA.trim();
  Serial.println(NMEA);
  NMEA="";
  flag=0;
  Timer1.restart();
}
}



void readGPS(){
 if (GPSSerial.available()>0){
  c=GPSSerial.read();
  NMEA.concat(c);
 }
  if(c=='\r'){
   flag=1;
 }
}

void loop(){

digitalWrite(RedLED,HIGH);

delay(1000);

digitalWrite(RedLED,LOW);

delay(1000);

if (flag==1){

Timer1.stop();

NMEA.trim();

Serial.println(NMEA);

NMEA="";

flag=0;

Timer1.restart();

}

void readGPS(){

if (GPSSerial.available()>0){

c=GPSSerial.read();

NMEA.concat(c);

}

if(c=='\r'){

flag=1;

}

While we do this demo for the Adafruit GPS, these techniques will work for other sensors that send data over the Serial Pins.

Beaglevone Black Rev. C

Beaglebone Black GPS Tracker LESSON 5: Displaying Data from GPS in Google Earth

June 23, 2015 admin

Google Earth GPS — Example of GPS Data displayed in Google Earth

In the earlier lessons in this series we learned how to hook the Adafruit Ultimate GPS up to the Beaglebone Black. In these lessons we got the hardware working, got to the point we could take data, and then got the NMEA sentences parsed, so that we could display understandable data for Latitude, Longitude, and Altitude. In this lesson we will show you how to create a GPS tracker, by logging your GPS data to a file on the Beaglebone Black. Then when you get back home, you can load the data into google earth to see an interactive view of where you have been.

The video shows step-by-step how to get the code working, starting with the code we developed in Lesson 3. We end up with the following program:

import serial
import Adafruit_BBIO.UART as UART
from time import sleep
UART.setup("UART1")
ser=serial.Serial('/dev/ttyO1',9600)
class GPS:
        def __init__(self):
                #This sets up variables for useful commands.
                #This set is used to set the rate the GPS reports
                UPDATE_10_sec=  "$PMTK220,10000*2F\r\n" #Update Every 10 Seconds
                UPDATE_5_sec=  "$PMTK220,5000*1B\r\n"   #Update Every 5 Seconds  
                UPDATE_1_sec=  "$PMTK220,1000*1F\r\n"   #Update Every One Second
                UPDATE_200_msec=  "$PMTK220,200*2C\r\n" #Update Every 200 Milliseconds
                #This set is used to set the rate the GPS takes measurements
                MEAS_10_sec = "$PMTK300,10000,0,0,0,0*2C\r\n" #Measure every 10 seconds
                MEAS_5_sec = "$PMTK300,5000,0,0,0,0*18\r\n"   #Measure every 5 seconds
                MEAS_1_sec = "$PMTK300,1000,0,0,0,0*1C\r\n"   #Measure once a second
                MEAS_200_msec= "$PMTK300,200,0,0,0,0*2F\r\n"  #Meaure 5 times a second
                #Set the Baud Rate of GPS
                BAUD_57600 = "$PMTK251,57600*2C\r\n"          #Set Baud Rate at 57600
                BAUD_9600 ="$PMTK251,9600*17\r\n"             #Set 9600 Baud Rate
                #Commands for which NMEA Sentences are sent
                ser.write(BAUD_57600)
                sleep(1)
                ser.baudrate=57600
                GPRMC_ONLY= "$PMTK314,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29\r\n" #Send only the GPRMC Sentence
                GPRMC_GPGGA="$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n"#Send GPRMC AND GPGGA Sentences
                SEND_ALL ="$PMTK314,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n" #Send All Sentences
                SEND_NOTHING="$PMTK314,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n" #Send Nothing
                ser.write(UPDATE_1_sec)
                sleep(1)
                ser.write(MEAS_1_sec)
                sleep(1)
                ser.write(GPRMC_GPGGA)
                sleep(1)
                ser.flushInput()
                ser.flushInput()
                print "GPS Initialized"
        def read(self):
                ser.flushInput()
                ser.flushInput()
                while ser.inWaiting()==0:
                        pass
                self.NMEA1=ser.readline()
                while ser.inWaiting()==0:
                        pass
                self.NMEA2=ser.readline()
                NMEA1_array=self.NMEA1.split(',')
                NMEA2_array=self.NMEA2.split(',')
                if NMEA1_array[0]=='$GPRMC':
                        self.timeUTC=NMEA1_array[1][:-8]+':'+NMEA1_array[1][-8:-6]+':'+NMEA1_array[1][-6:-4]
                        self.latDeg=NMEA1_array[3][:-7]
                        self.latMin=NMEA1_array[3][-7:]
                        self.latHem=NMEA1_array[4]
                        self.lonDeg=NMEA1_array[5][:-7]
                        self.lonMin=NMEA1_array[5][-7:]
                        self.lonHem=NMEA1_array[6]
                        self.knots=NMEA1_array[7]
                if NMEA1_array[0]=='$GPGGA':
                        self.fix=NMEA1_array[6]
                        self.altitude=NMEA1_array[9]
                        self.sats=NMEA1_array[7]
                if NMEA2_array[0]=='$GPRMC':
                        self.timeUTC=NMEA2_array[1][:-8]+':'+NMEA1_array[1][-8:-6]+':'+NMEA1_array[1][-6:-4]
                        self.latDeg=NMEA2_array[3][:-7]
                        self.latMin=NMEA2_array[3][-7:]
                        self.latHem=NMEA2_array[4]
                        self.lonDeg=NMEA2_array[5][:-7]
                        self.lonMin=NMEA2_array[5][-7:]
                        self.lonHem=NMEA2_array[6]
                        self.knots=NMEA2_array[7]

                if NMEA2_array[0]=='$GPGGA':
                        self.fix=NMEA2_array[6]
                        self.altitude=NMEA2_array[9]
                        self.sats=NMEA2_array[7]
myGPS=GPS()
GPSdata=open('/root/GPS_data/GPS.txt', 'w')
GPSdata.close()
while(1):
        myGPS.read()
        if myGPS.fix!=0:
                try:
			latDec=float(myGPS.latDeg)+float(myGPS.latMin)/60.
			lonDec=float(myGPS.lonDeg)+float(myGPS.lonMin)/60.
			if myGPS.lonHem=='W':
				lonDec=(-1)*lonDec
			if myGPS.latHem=='S':
				latDec=(-1)*latDec
			alt=myGPS.altitude
			GPSdata=open('/root/GPS_data/GPS.txt', 'a')
			myString=str(lonDec)+','+str(latDec)+','+alt+' '
			GPSdata.write(myString)
			GPSdata.close()
		except:
			pass

import serial

import Adafruit_BBIO.UART as UART

from time import sleep

UART.setup("UART1")

ser=serial.Serial('/dev/ttyO1',9600)

class GPS:

def __init__(self):

#This sets up variables for useful commands.

#This set is used to set the rate the GPS reports

UPDATE_10_sec= "$PMTK220,10000*2F\r\n" #Update Every 10 Seconds

UPDATE_5_sec= "$PMTK220,5000*1B\r\n" #Update Every 5 Seconds

UPDATE_1_sec= "$PMTK220,1000*1F\r\n" #Update Every One Second

UPDATE_200_msec= "$PMTK220,200*2C\r\n" #Update Every 200 Milliseconds

#This set is used to set the rate the GPS takes measurements

MEAS_10_sec = "$PMTK300,10000,0,0,0,0*2C\r\n" #Measure every 10 seconds

MEAS_5_sec = "$PMTK300,5000,0,0,0,0*18\r\n" #Measure every 5 seconds

MEAS_1_sec = "$PMTK300,1000,0,0,0,0*1C\r\n" #Measure once a second

MEAS_200_msec= "$PMTK300,200,0,0,0,0*2F\r\n" #Meaure 5 times a second

#Set the Baud Rate of GPS

BAUD_57600 = "$PMTK251,57600*2C\r\n" #Set Baud Rate at 57600

BAUD_9600 ="$PMTK251,9600*17\r\n" #Set 9600 Baud Rate

#Commands for which NMEA Sentences are sent

ser.write(BAUD_57600)

sleep(1)

ser.baudrate=57600

GPRMC_ONLY= "$PMTK314,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29\r\n" #Send only the GPRMC Sentence

GPRMC_GPGGA="$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n"#Send GPRMC AND GPGGA Sentences

SEND_ALL ="$PMTK314,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n" #Send All Sentences

SEND_NOTHING="$PMTK314,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n" #Send Nothing

ser.write(UPDATE_1_sec)

sleep(1)

ser.write(MEAS_1_sec)

sleep(1)

ser.write(GPRMC_GPGGA)

sleep(1)

ser.flushInput()

print "GPS Initialized"

def read(self):

ser.flushInput()

while ser.inWaiting()==0:

pass

self.NMEA1=ser.readline()

while ser.inWaiting()==0:

pass

self.NMEA2=ser.readline()

NMEA1_array=self.NMEA1.split(',')

NMEA2_array=self.NMEA2.split(',')

if NMEA1_array[0]=='$GPRMC':

self.timeUTC=NMEA1_array[1][:-8]+':'+NMEA1_array[1][-8:-6]+':'+NMEA1_array[1][-6:-4]

self.latDeg=NMEA1_array[3][:-7]

self.latMin=NMEA1_array[3][-7:]

self.latHem=NMEA1_array[4]

self.lonDeg=NMEA1_array[5][:-7]

self.lonMin=NMEA1_array[5][-7:]

self.lonHem=NMEA1_array[6]

self.knots=NMEA1_array[7]

if NMEA1_array[0]=='$GPGGA':

self.fix=NMEA1_array[6]

self.altitude=NMEA1_array[9]

self.sats=NMEA1_array[7]

if NMEA2_array[0]=='$GPRMC':

self.timeUTC=NMEA2_array[1][:-8]+':'+NMEA1_array[1][-8:-6]+':'+NMEA1_array[1][-6:-4]

self.latDeg=NMEA2_array[3][:-7]

self.latMin=NMEA2_array[3][-7:]

self.latHem=NMEA2_array[4]

self.lonDeg=NMEA2_array[5][:-7]

self.lonMin=NMEA2_array[5][-7:]

self.lonHem=NMEA2_array[6]

self.knots=NMEA2_array[7]

if NMEA2_array[0]=='$GPGGA':

self.fix=NMEA2_array[6]

self.altitude=NMEA2_array[9]

self.sats=NMEA2_array[7]

myGPS=GPS()

GPSdata=open('/root/GPS_data/GPS.txt', 'w')

GPSdata.close()

while(1):

myGPS.read()

if myGPS.fix!=0:

try:

latDec=float(myGPS.latDeg)+float(myGPS.latMin)/60.

lonDec=float(myGPS.lonDeg)+float(myGPS.lonMin)/60.

if myGPS.lonHem=='W':

lonDec=(-1)*lonDec

if myGPS.latHem=='S':

latDec=(-1)*latDec

alt=myGPS.altitude

GPSdata=open('/root/GPS_data/GPS.txt', 'a')

myString=str(lonDec)+','+str(latDec)+','+alt+' '

GPSdata.write(myString)

GPSdata.close()

except:

pass

This program should create a file on the Beaglebone Black, and track your longitude, latitude and altitude.

In order to view the file on Google Earth, you will want to put a KMZ wrapper on the coordinates. A reasonable KMZ wrapper is below. Simply take your coordinates from the program above, and paste them in the file below, in the area between <coordinates> and </coordinates>

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
<Document>
<Style id="yellowPoly">
<LineStyle>
<color>7f00ffff</color>
<width>4</width>
</LineStyle>
<PolyStyle>
<color>7f00ff00</color>
</PolyStyle>
</Style>
<Placemark><styleUrl>#yellowPoly</styleUrl>
<LineString>
<extrude>1</extrude>
<tesselate>1</tesselate>
<altitudeMode>absolute</altitudeMode>
<coordinates>




</coordinates>
</LineString></Placemark>

</Document></kml>

<?xml version="1.0" encoding="UTF-8"?>

</LineStyle>

</PolyStyle>

</Style>

<Placemark><styleUrl>#yellowPoly</styleUrl>

<altitudeMode>absolute</altitudeMode>

</coordinates>

</LineString></Placemark>

</Document></kml>

Technology Tutorials

Tag Archives: Adafruit Ultimate GPS

Getting Latitude and Longitude from the Adafruit Ultimate GPS with Raspberry Pi Pico W

Connecting the Adafruit Ultimate GPS to the Raspberry Pi Pico W

Getting Geared Up for the Ultimate GPS Tracker with Raspberry Pi Pico W

LESSON 30: Advanced Software Interrupt Techniques for Reading Serial Data with Arduino

Beaglebone Black GPS Tracker LESSON 5: Displaying Data from GPS in Google Earth

Making The World a Better Place One High Tech Project at a Time. Enjoy!