In today’s video lesson we show how you can remove the vibration noise from your roll and pitch values using a low pass filter. The filter removes the high frequency noise resulting from vibrations.

MPU6050 — Schematic for connecting the GY-87 module to the Arduino

Below is the code we developed in this lesson.

#include <Adafruit_MPU6050.h>
#include <Adafruit_Sensor.h>
#include <Wire.h>
float Ax;
float Ay;
float Az;

// If You want Calibrated results, you must rotate
// your board to all possible orientations, and 
// record your velues of xMax, xMin, yMax, yMin
// zMax, zMin. I show you how to do that in LESSON
// 79 on my youtube channel. Put in your values and then
// uncomment the code below. Don't use my values, you have
// to measure your own for it to work.

// float xMax= 1.03;
// float xMin= -.97;
// float yMax= .98;
// float yMin= -1.01;
// float zMax=.96 ;
// float zMin= -1.08;

// float xOffset = (xMax+xMin)/2;
// float yOffset = (yMax+yMin)/2;
// float zOffset = (zMax+zMin)/2;

// float xScale = 2/(xMax -xMin);
// float yScale = 2/(yMax - yMin);
// float zScale = 2/(zMax -zMin);

float roll=0;
float pitch=0;
float rollRAW;
float pitchRAW;

Adafruit_MPU6050 mpu;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  mpu.begin();
  Serial.println("MPU6050 Started!");
  mpu.setAccelerometerRange(MPU6050_RANGE_2_G);
  mpu.setFilterBandwidth(MPU6050_BAND_21_HZ);


}

void loop() {
  // put your main code here, to run repeatedly:
  sensors_event_t a, g, temp;
  mpu.getEvent(&a, &g, &temp);
  Ax=a.acceleration.x/9.81;
  Ay=a.acceleration.y/9.81;
  Az=a.acceleration.z/9.81;

//Uncomment these lines of code to do the callibration
//This will only work if you have measured your max
//and min values, and put them in at the top of the code
  // Ax = xScale*(Ax-xOffset);
  // Ay = yScale*(Ay-yOffset);
  // Az = zScale*(Az-zOffset);

  pitchRAW = atan2(Ay,sqrt(Az*Az+Ax*Ax))*360/(2*3.14);
  rollRAW = atan2(Ax,sqrt(Az*Az+Ay*Ay))*360/(2*3.14);

  pitch = .75*pitch + .25*pitchRAW;
  roll = .75*roll + .25*rollRAW;

  Serial.print("RollRAW:");
  Serial.print(rollRAW);
  Serial.print(',');
  Serial.print("PitchRAW:");
  Serial.print(pitchRAW);
    Serial.print(',');
  Serial.print("Roll:");
  Serial.print(roll);
  Serial.print(',');
  Serial.print("Pitch:");
  Serial.print(pitch);
    Serial.print(',');
   Serial.print("UL:");
 Serial.print(90);
 Serial.print(',');
 Serial.print("LL:");
 Serial.println(-90);



//   Serial.print("Ax:");
//   Serial.print(Ax);
//   Serial.print(',');
//   Serial.print("Ay:");
//   Serial.print(Ay);
//   Serial.print(',');
//     Serial.print("Az:");
//   Serial.print(Az);
//   Serial.print(',');
//  Serial.print("UL:");
//  Serial.print(1);
//  Serial.print(',');
//  Serial.print("LL:");
//  Serial.println(-1);

  delay(50);

}

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#include <Adafruit_MPU6050.h>

#include <Adafruit_Sensor.h>

#include <Wire.h>

float Ax;

float Ay;

float Az;

// If You want Calibrated results, you must rotate

// your board to all possible orientations, and

// record your velues of xMax, xMin, yMax, yMin

// zMax, zMin. I show you how to do that in LESSON

// 79 on my youtube channel. Put in your values and then

// uncomment the code below. Don't use my values, you have

// to measure your own for it to work.

// float xMax= 1.03;

// float xMin= -.97;

// float yMax= .98;

// float yMin= -1.01;

// float zMax=.96 ;

// float zMin= -1.08;

// float xOffset = (xMax+xMin)/2;

// float yOffset = (yMax+yMin)/2;

// float zOffset = (zMax+zMin)/2;

// float xScale = 2/(xMax -xMin);

// float yScale = 2/(yMax - yMin);

// float zScale = 2/(zMax -zMin);

float roll=0;

float pitch=0;

float rollRAW;

float pitchRAW;

Adafruit_MPU6050 mpu;

void setup() {

// put your setup code here, to run once:

Serial.begin(115200);

mpu.begin();

Serial.println("MPU6050 Started!");

mpu.setAccelerometerRange(MPU6050_RANGE_2_G);

mpu.setFilterBandwidth(MPU6050_BAND_21_HZ);

}

void loop() {

// put your main code here, to run repeatedly:

sensors_event_t a, g, temp;

mpu.getEvent(&a, &g, &temp);

Ax=a.acceleration.x/9.81;

Ay=a.acceleration.y/9.81;

Az=a.acceleration.z/9.81;

//Uncomment these lines of code to do the callibration

//This will only work if you have measured your max

//and min values, and put them in at the top of the code

// Ax = xScale*(Ax-xOffset);

// Ay = yScale*(Ay-yOffset);

// Az = zScale*(Az-zOffset);

pitchRAW = atan2(Ay,sqrt(Az*Az+Ax*Ax))*360/(2*3.14);

rollRAW = atan2(Ax,sqrt(Az*Az+Ay*Ay))*360/(2*3.14);

pitch = .75*pitch + .25*pitchRAW;

roll = .75*roll + .25*rollRAW;

Serial.print("RollRAW:");

Serial.print(rollRAW);

Serial.print(',');

Serial.print("PitchRAW:");

Serial.print(pitchRAW);

Serial.print(',');

Serial.print("Roll:");

Serial.print(roll);

Serial.print(',');

Serial.print("Pitch:");

Serial.print(pitch);

Serial.print(',');

Serial.print("UL:");

Serial.print(90);

Serial.print(',');

Serial.print("LL:");

Serial.println(-90);

// Serial.print("Ax:");

// Serial.print(Ax);

// Serial.print(',');

// Serial.print("Ay:");

// Serial.print(Ay);

// Serial.print(',');

// Serial.print("Az:");

// Serial.print(Az);

// Serial.print(',');

// Serial.print("UL:");

// Serial.print(1);

// Serial.print(',');

// Serial.print("LL:");

// Serial.println(-1);

delay(50);

}

MicroPython, Raspberry Pi Pico, Tutorial

Getting Altitude Data from the GPS NMEA Sentences

August 12, 2025 admin

In this video lesson we show you how you can parse NMEA sentence from your Adafruit Ultimate GPS to get the Altitude of your GPS tracker. At this point, our project has grown to the point that all our data will not fit on the small OLED screen, so we have also added pushbuttons to allow us to toggle between display screens. For this project we are using the following circuit schematic:

For your convenience, the code developed in the video is below:

from machine import Pin,I2C,UART
import time
import _thread
from ssd1306 import SSD1306_I2C

utcCorrect = 3

i2c2 = I2C(1, sda=Pin(2), scl=Pin(3), freq=400000)
dsp = SSD1306_I2C(128,64,i2c2)

dataLock = _thread.allocate_lock()
keepRunning = True
GPS = UART(1, baudrate=9600, tx=machine.Pin(8), rx=machine.Pin(9))
# Reset GPS
GPS.write(b'$PMTK314,-1*04\r\n')
#The following line ensures that the GPS reports the GPVTG NMEA Sentence
GPS.write(b"$PMTK314,0,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n")
NMEAdata = {
    'GPGGA' : "",
    'GPGSA' : "",
    'GPRMC' : "",
    'GPVTG' : ""
    }
GPSdata = {
    'latDD' 	: 0,
    'lonDD'		: 0,
    'heading'	: 0,
    'fix'		: False,
    'sats'		: 0,
    'knots'		: 0,
    'time'		: '00:00:00',
    'date'		: '00/00/0000',
    'alt'		: 0.0
    }
def gpsThread():
    print("Thread Running")
    global keepRunning,NMEAdata
    GPGGA = ""
    GPGSA = ""
    GPRMC = ""
    GPVTG = ""
    while not GPS.any():
        pass
    while GPS.any():
        junk = GPS.read()
        print(junk)
    myNMEA = ""
    while keepRunning:
        if GPS.any():
            myChar=GPS.read(1).decode('utf-8')
            myNMEA = myNMEA + myChar
            if myChar == '\n':
                myNMEA = myNMEA.strip()
                if myNMEA[1:6] == "GPGGA":
                    GPGGA = myNMEA
                if myNMEA[1:6] == "GPGSA":
                    GPGSA = myNMEA
                if myNMEA[1:6] == "GPRMC":
                    GPRMC = myNMEA
                if myNMEA[1:6] == "GPVTG":
                    GPVTG = myNMEA
                if GPGGA != "" and GPGSA!="" and GPRMC!="" and GPVTG!="":
                    dataLock.acquire()
                    NMEAdata = {
                        'GPGGA' : GPGGA,
                        'GPGSA' : GPGSA,
                        'GPRMC' : GPRMC,
                        'GPVTG' : GPVTG
                        }
                    dataLock.release()
                myNMEA = ""
    print("Thread Terminated Cleanly")
def parseGPS():
    readFix=int(NMEAmain['GPGGA'].split(',')[6])
    if readFix !=0:
        GPSdata['fix'] = True
        latRAW = NMEAmain['GPGGA'].split(',')[2]
        latDD = int(latRAW[0:2]) + float(latRAW[2:])/60
        if NMEAmain['GPGGA'].split(',')[3] == 'S':
            latDD = -latDD
        GPSdata['latDD']= latDD
        lonRAW=NMEAmain['GPGGA'].split(',')[4]
        lonDD=int(lonRAW[0:3]) + float(lonRAW[3:])/60
        if NMEAmain['GPGGA'].split(',')[5] == 'W':
            lonDD = -lonDD
        GPSdata['lonDD'] = lonDD
        heading = float(NMEAmain['GPRMC'].split(',')[8])
        GPSdata['heading'] = heading
        knots = float(NMEAmain['GPRMC'].split(',')[7])
        GPSdata['knots'] = knots
        sats = int(NMEAmain['GPGGA'].split(',')[7])
        GPSdata['sats'] = sats
        utcTime = NMEAmain['GPGGA'].split(',')[1]
        utcDate = NMEAmain['GPRMC'].split(',')[9]
        # utcTime = "013445.000"
        # utcDate = "010125"

        # Extract year from UTC date (format: DDMMYY), prepend '20' for full year (e.g., '25' → '2025')
        myYear = '20' + utcDate[4:]
        # Extract month from UTC date (e.g., '01' for January)
        myMonth = utcDate[2:4]
        # Extract day from UTC date (e.g., '01' for 1st)
        myDay = utcDate[0:2]
        # Calculate hours by adding UTC offset to UTC hours, convert to string
        myHours = str(int(utcTime[0:2]) + utcCorrect)
        # Extract minutes from UTC time (e.g., '34' from '013445.000')
        myMin = utcTime[2:4]
        # Extract seconds from UTC time (e.g., '45' from '013445.000')
        mySec = utcTime[4:6]

        # Define array of maximum days per month (index 0-11 for months 1-12: Jan to Dec)
        maxDays = ['31', '28', '31', '30', '31', '30', '31', '31', '30', '31', '30', '31']

        # Check if year is a leap year (simplified: divisible by 4); if so, set February to 29 days
        if int(myYear) % 4 == 0:
            maxDays[1] = '29'

        # Check if hours exceed 24 (for positive UTC offsets, e.g., UTC 22:00 + 5 = 27:00)
        if int(myHours) >= 24:
            # Subtract 24 from hours to wrap around to next day (e.g., 27 → 3)
            myHours = str(int(myHours) - 24)
            # Pad hours with leading zero if single digit (e.g., '3' → '03')
            if len(myHours) < 2:
                myHours = '0' + myHours
            # Increment day to account for crossing midnight (e.g., 30 → 31)
            myDay = str(int(myDay) + 1)
            # Check if day exceeds maximum days for the current month (e.g., June 31 > 30)
            if int(myDay) > int(maxDays[int(myMonth) - 1]):
                # Reset day to 1 for the next month
                myDay = '01'
                # Increment month (e.g., June → July)
                myMonth = str(int(myMonth) + 1)
                # Check if month exceeds 12 (e.g., December → January)
                if int(myMonth) > 12:
                    # Reset month to January
                    myMonth = '01'
                    # Increment year (e.g., 2025 → 2026)
                    myYear = str(int(myYear) + 1)
            # Pad day with leading zero if single digit (e.g., '1' → '01')
            if len(myDay) < 2:
                myDay = '0' + myDay
            # Pad month with leading zero if single digit (e.g., '7' → '07')
            if len(myMonth) < 2:
                myMonth = '0' + myMonth

        # Check if hours are negative (for negative UTC offsets, e.g., UTC 01:00 - 5 = -4)
        if int(myHours) < 0:
            # Add 24 to hours to wrap around to previous day (e.g., -4 → 20)
            myHours = str(int(myHours) + 24)
            # Pad hours with leading zero if single digit (e.g., '3' → '03')
            if len(myHours) < 2:
                myHours = '0' + myHours
            # Decrement day to account for crossing midnight backward (e.g., 01 → 00)
            myDay = str(int(myDay) - 1)
            # Check if day is less than 1 (e.g., January 1 → December 31)
            if int(myDay) < 1:
                # Decrement month (e.g., January → December)
                myMonth = str(int(myMonth) - 1)
                # Check if month is less than 1 (e.g., January → December of previous year)
                if int(myMonth) < 1:
                    # Set month to December
                    myMonth = '12'
                    # Decrement year (e.g., 2025 → 2024)
                    myYear = str(int(myYear) - 1)
                # Set day to maximum days of the new month (e.g., December → 31)
                myDay = maxDays[int(myMonth) - 1]
            # Pad day with leading zero if single digit (e.g., '1' → '01')
            if len(myDay) < 2:
                myDay = '0' + myDay
            # Pad month with leading zero if single digit (e.g., '7' → '07')
            if len(myMonth) < 2:
                myMonth = '0' + myMonth

        # Combine hours, minutes, seconds into time string (e.g., '20:34:45')
        myTime = myHours + ':' + myMin + ':' + mySec
        # Combine month, day, year into date string (e.g., '12/31/2024')
        myDate = myMonth + '/' + myDay + '/' + myYear
        # Store local time in GPSdata dictionary
        GPSdata['time'] = myTime
        # Store local date in GPSdata dictionary
        GPSdata['date'] = myDate
        GPSdata['alt'] = float(NMEAmain['GPGGA'].split(',')[9])
def dispOLED():
    dsp.fill(0)
    if GPSdata['fix'] == False:
        dsp.text("Waiting for Fix . . .",0,0)
    if GPSdata['fix'] == True:
        if screenOne==True:
            dsp.fill(0)
            dsp.text("Ultimate GPS",0,0)
            dsp.text(GPSdata['date'][0:5] + ' '+GPSdata['time'],0,16)
            dsp.text("LAT: "+str(GPSdata['latDD']),0,26)
            dsp.text("LON: "+str(GPSdata['lonDD']),0,36)
            dsp.text("SATS: "+str(GPSdata['sats']),0,46)

        if screenOne==False:
            dsp.fill(0)
            dsp.text("Ultimate GPS",0,0)
            dsp.text(GPSdata['date'][0:5] + ' '+GPSdata['time'],0,16)
            dsp.text("SPEED: "+str(GPSdata['knots'])+' Knts',0,26)
            dsp.text("HEAD: "+str(GPSdata['heading'])+'deg.',0,36)
            dsp.text("Alt: "+str(GPSdata['alt'])+' M',0,46)
    dsp.show()
butOnePin = 12
butOne = Pin(butOnePin, Pin.IN, Pin.PULL_UP)
butOneUp = 0
butOneDown = 0
butOneOld = 1

screenOne = True

def butOneIRQ(pin):
    global butOneUp,butOneDown,butOneOld,screenOne
    butOneValue = butOne.value()
    if butOneValue==0:
        butOneDown=time.ticks_ms()
    if butOneValue==1:
        butOneUp = time.ticks_ms()
    if butOneOld==1 and butOneValue==0 and butOneDown-butOneUp>50:
        screenOne = not screenOne
        print('Button One Triggered')
    butOneOld=butOneValue
    
butOne.irq(trigger=Pin.IRQ_FALLING | Pin.IRQ_RISING , handler = butOneIRQ)
 
_thread.start_new_thread(gpsThread,())
time.sleep(3)
try:
    while True:
        dataLock.acquire()
        NMEAmain = NMEAdata.copy()
        dataLock.release()
        parseGPS()
        if GPSdata['fix'] == False:
            print("Waiting for Fix . . .")
        if GPSdata['fix'] == True:
            print("Ultimate GPS Tracker Report: ")
            print(GPSdata['time'],GPSdata['date'])
            print("Lat and Lon: ",GPSdata['latDD'],GPSdata['lonDD'])
            print("Knots: ",GPSdata['knots'])
            print("Heading: ",GPSdata['heading'])
            print("Elevation: ",GPSdata['alt'])
            print("Sats: ",GPSdata['sats'])
            print()
        dispOLED()
        time.sleep(1)


except KeyboardInterrupt:
    print("\nStopping Program . . . Cleaning Up UART")
    keepRunning = False
    time.sleep(1)
    GPS.deinit()
    time.sleep(1)
    dsp.fill(0)
    dsp.show()
    print("Exited Cleanly")

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from machine import Pin,I2C,UART

import time

import _thread

from ssd1306 import SSD1306_I2C

utcCorrect = 3

i2c2 = I2C(1, sda=Pin(2), scl=Pin(3), freq=400000)

dsp = SSD1306_I2C(128,64,i2c2)

dataLock = _thread.allocate_lock()

keepRunning = True

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

# Reset GPS

GPS.write(b'$PMTK314,-1*04\r\n')

#The following line ensures that the GPS reports the GPVTG NMEA Sentence

GPS.write(b"$PMTK314,0,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n")

NMEAdata = {

'GPGGA' : "",

'GPGSA' : "",

'GPRMC' : "",

'GPVTG' : ""

}

GPSdata = {

'latDD' : 0,

'lonDD' : 0,

'heading' : 0,

'fix' : False,

'sats' : 0,

'knots' : 0,

'time' : '00:00:00',

'date' : '00/00/0000',

'alt' : 0.0

}

def gpsThread():

print("Thread Running")

global keepRunning,NMEAdata

GPGGA = ""

GPGSA = ""

GPRMC = ""

GPVTG = ""

while not GPS.any():

pass

while GPS.any():

junk = GPS.read()

print(junk)

myNMEA = ""

while keepRunning:

if GPS.any():

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

myNMEA = myNMEA + myChar

if myChar == '\n':

myNMEA = myNMEA.strip()

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

GPGGA = myNMEA

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

GPGSA = myNMEA

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

GPRMC = myNMEA

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

GPVTG = myNMEA

if GPGGA != "" and GPGSA!="" and GPRMC!="" and GPVTG!="":

dataLock.acquire()

NMEAdata = {

'GPGGA' : GPGGA,

'GPGSA' : GPGSA,

'GPRMC' : GPRMC,

'GPVTG' : GPVTG

}

dataLock.release()

myNMEA = ""

print("Thread Terminated Cleanly")

def parseGPS():

readFix=int(NMEAmain['GPGGA'].split(',')[6])

if readFix !=0:

GPSdata['fix'] = True

latRAW = NMEAmain['GPGGA'].split(',')[2]

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

if NMEAmain['GPGGA'].split(',')[3] == 'S':

latDD = -latDD

GPSdata['latDD']= latDD

lonRAW=NMEAmain['GPGGA'].split(',')[4]

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

if NMEAmain['GPGGA'].split(',')[5] == 'W':

lonDD = -lonDD

GPSdata['lonDD'] = lonDD

heading = float(NMEAmain['GPRMC'].split(',')[8])

GPSdata['heading'] = heading

knots = float(NMEAmain['GPRMC'].split(',')[7])

GPSdata['knots'] = knots

sats = int(NMEAmain['GPGGA'].split(',')[7])

GPSdata['sats'] = sats

utcTime = NMEAmain['GPGGA'].split(',')[1]

utcDate = NMEAmain['GPRMC'].split(',')[9]

# utcTime = "013445.000"

# utcDate = "010125"

# Extract year from UTC date (format: DDMMYY), prepend '20' for full year (e.g., '25' → '2025')

myYear = '20' + utcDate[4:]

# Extract month from UTC date (e.g., '01' for January)

myMonth = utcDate[2:4]

# Extract day from UTC date (e.g., '01' for 1st)

myDay = utcDate[0:2]

# Calculate hours by adding UTC offset to UTC hours, convert to string

myHours = str(int(utcTime[0:2]) + utcCorrect)

# Extract minutes from UTC time (e.g., '34' from '013445.000')

myMin = utcTime[2:4]

# Extract seconds from UTC time (e.g., '45' from '013445.000')

mySec = utcTime[4:6]

# Define array of maximum days per month (index 0-11 for months 1-12: Jan to Dec)

maxDays = ['31', '28', '31', '30', '31', '30', '31', '31', '30', '31', '30', '31']

# Check if year is a leap year (simplified: divisible by 4); if so, set February to 29 days

if int(myYear) % 4 == 0:

maxDays[1] = '29'

# Check if hours exceed 24 (for positive UTC offsets, e.g., UTC 22:00 + 5 = 27:00)

if int(myHours) >= 24:

# Subtract 24 from hours to wrap around to next day (e.g., 27 → 3)

myHours = str(int(myHours) - 24)

# Pad hours with leading zero if single digit (e.g., '3' → '03')

if len(myHours) < 2:

myHours = '0' + myHours

# Increment day to account for crossing midnight (e.g., 30 → 31)

myDay = str(int(myDay) + 1)

# Check if day exceeds maximum days for the current month (e.g., June 31 > 30)

if int(myDay) > int(maxDays[int(myMonth) - 1]):

# Reset day to 1 for the next month

myDay = '01'

# Increment month (e.g., June → July)

myMonth = str(int(myMonth) + 1)

# Check if month exceeds 12 (e.g., December → January)

if int(myMonth) > 12:

# Reset month to January

myMonth = '01'

# Increment year (e.g., 2025 → 2026)

myYear = str(int(myYear) + 1)

# Pad day with leading zero if single digit (e.g., '1' → '01')

if len(myDay) < 2:

myDay = '0' + myDay

# Pad month with leading zero if single digit (e.g., '7' → '07')

if len(myMonth) < 2:

myMonth = '0' + myMonth

# Check if hours are negative (for negative UTC offsets, e.g., UTC 01:00 - 5 = -4)

if int(myHours) < 0:

# Add 24 to hours to wrap around to previous day (e.g., -4 → 20)

myHours = str(int(myHours) + 24)

# Pad hours with leading zero if single digit (e.g., '3' → '03')

if len(myHours) < 2:

myHours = '0' + myHours

# Decrement day to account for crossing midnight backward (e.g., 01 → 00)

myDay = str(int(myDay) - 1)

# Check if day is less than 1 (e.g., January 1 → December 31)

if int(myDay) < 1:

# Decrement month (e.g., January → December)

myMonth = str(int(myMonth) - 1)

# Check if month is less than 1 (e.g., January → December of previous year)

if int(myMonth) < 1:

# Set month to December

myMonth = '12'

# Decrement year (e.g., 2025 → 2024)

myYear = str(int(myYear) - 1)

# Set day to maximum days of the new month (e.g., December → 31)

myDay = maxDays[int(myMonth) - 1]

# Pad day with leading zero if single digit (e.g., '1' → '01')

if len(myDay) < 2:

myDay = '0' + myDay

# Pad month with leading zero if single digit (e.g., '7' → '07')

if len(myMonth) < 2:

myMonth = '0' + myMonth

# Combine hours, minutes, seconds into time string (e.g., '20:34:45')

myTime = myHours + ':' + myMin + ':' + mySec

# Combine month, day, year into date string (e.g., '12/31/2024')

myDate = myMonth + '/' + myDay + '/' + myYear

# Store local time in GPSdata dictionary

GPSdata['time'] = myTime

# Store local date in GPSdata dictionary

GPSdata['date'] = myDate

GPSdata['alt'] = float(NMEAmain['GPGGA'].split(',')[9])

def dispOLED():

dsp.fill(0)

if GPSdata['fix'] == False:

dsp.text("Waiting for Fix . . .",0,0)

if GPSdata['fix'] == True:

if screenOne==True:

dsp.fill(0)

dsp.text("Ultimate GPS",0,0)

dsp.text(GPSdata['date'][0:5] + ' '+GPSdata['time'],0,16)

dsp.text("LAT: "+str(GPSdata['latDD']),0,26)

dsp.text("LON: "+str(GPSdata['lonDD']),0,36)

dsp.text("SATS: "+str(GPSdata['sats']),0,46)

if screenOne==False:

dsp.fill(0)

dsp.text("Ultimate GPS",0,0)

dsp.text(GPSdata['date'][0:5] + ' '+GPSdata['time'],0,16)

dsp.text("SPEED: "+str(GPSdata['knots'])+' Knts',0,26)

dsp.text("HEAD: "+str(GPSdata['heading'])+'deg.',0,36)

dsp.text("Alt: "+str(GPSdata['alt'])+' M',0,46)

dsp.show()

butOnePin = 12

butOne = Pin(butOnePin, Pin.IN, Pin.PULL_UP)

butOneUp = 0

butOneDown = 0

butOneOld = 1

screenOne = True

def butOneIRQ(pin):

global butOneUp,butOneDown,butOneOld,screenOne

butOneValue = butOne.value()

if butOneValue==0:

butOneDown=time.ticks_ms()

if butOneValue==1:

butOneUp = time.ticks_ms()

if butOneOld==1 and butOneValue==0 and butOneDown-butOneUp>50:

screenOne = not screenOne

print('Button One Triggered')

butOneOld=butOneValue

butOne.irq(trigger=Pin.IRQ_FALLING | Pin.IRQ_RISING , handler = butOneIRQ)

_thread.start_new_thread(gpsThread,())

time.sleep(3)

try:

while True:

dataLock.acquire()

NMEAmain = NMEAdata.copy()

dataLock.release()

parseGPS()

if GPSdata['fix'] == False:

print("Waiting for Fix . . .")

if GPSdata['fix'] == True:

print("Ultimate GPS Tracker Report: ")

print(GPSdata['time'],GPSdata['date'])

print("Lat and Lon: ",GPSdata['latDD'],GPSdata['lonDD'])

print("Knots: ",GPSdata['knots'])

print("Heading: ",GPSdata['heading'])

print("Elevation: ",GPSdata['alt'])

print("Sats: ",GPSdata['sats'])

print()

dispOLED()

time.sleep(1)

except KeyboardInterrupt:

print("\nStopping Program . . . Cleaning Up UART")

keepRunning = False

time.sleep(1)

GPS.deinit()

time.sleep(1)

dsp.fill(0)

dsp.show()

print("Exited Cleanly")

Arduino

Using Arduino to Calculate Roll and Pitch from MPU6050 3-axis Accelerometers

August 7, 2025 admin

In this video lesson we show you how to take the calibrated accelerometer data from the MPU6050 and use it to calculate the tilt of the board. We can calculate tilt in two axis, or the roll and the pitch. This is the schematic for the project:

This is the code we developed in the video to calculate the roll and pitch from the three axis accelerometer data.

#include <Adafruit_MPU6050.h>
#include <Adafruit_Sensor.h>
#include <Wire.h>
float Ax;
float Ay;
float Az;

// If You want Calibrated results, you must rotate
// your board to all possible orientations, and 
// record your velues of xMax, xMin, yMax, yMin
// zMax, zMin. I show you how to do that in LESSON
// 79 on my youtube channel. Put in your values and then
// uncomment the code below. Don't use my values, you have
// to measure your own for it to work.

// float xMax= 1.03;
// float xMin= -.97;
// float yMax= .98;
// float yMin= -1.01;
// float zMax=.96 ;
// float zMin= -1.08;

// float xOffset = (xMax+xMin)/2;
// float yOffset = (yMax+yMin)/2;
// float zOffset = (zMax+zMin)/2;

// float xScale = 2/(xMax -xMin);
// float yScale = 2/(yMax - yMin);
// float zScale = 2/(zMax -zMin);

float roll;
float pitch;

Adafruit_MPU6050 mpu;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  mpu.begin();
  Serial.println("MPU6050 Started!");
  mpu.setAccelerometerRange(MPU6050_RANGE_2_G);
  mpu.setFilterBandwidth(MPU6050_BAND_21_HZ);


}

void loop() {
  // put your main code here, to run repeatedly:
  sensors_event_t a, g, temp;
  mpu.getEvent(&a, &g, &temp);
  Ax=a.acceleration.x/9.81;
  Ay=a.acceleration.y/9.81;
  Az=a.acceleration.z/9.81;

//Uncomment these lines of code to do the callibration
//This will only work if you have measured your max
//and min values, and put them in at the top of the code
  // Ax = xScale*(Ax-xOffset);
  // Ay = yScale*(Ay-yOffset);
  // Az = zScale*(Az-zOffset);

  pitch = atan2(Ay,sqrt(Az*Az+Ax*Ax))*360/(2*3.14);
  roll = atan2(Ax,sqrt(Az*Az+Ay*Ay))*360/(2*3.14);

  Serial.print("Roll:");
  Serial.print(roll);
  Serial.print(',');
  Serial.print("Pitch:");
  Serial.print(pitch);
    Serial.print(',');
   Serial.print("UL:");
 Serial.print(90);
 Serial.print(',');
 Serial.print("LL:");
 Serial.println(-90);



//   Serial.print("Ax:");
//   Serial.print(Ax);
//   Serial.print(',');
//   Serial.print("Ay:");
//   Serial.print(Ay);
//   Serial.print(',');
//     Serial.print("Az:");
//   Serial.print(Az);
//   Serial.print(',');
//  Serial.print("UL:");
//  Serial.print(1);
//  Serial.print(',');
//  Serial.print("LL:");
//  Serial.println(-1);

  delay(50);

}

#include <Adafruit_MPU6050.h>

#include <Adafruit_Sensor.h>

#include <Wire.h>

float Ax;

float Ay;

float Az;

// If You want Calibrated results, you must rotate

// your board to all possible orientations, and

// record your velues of xMax, xMin, yMax, yMin

// zMax, zMin. I show you how to do that in LESSON

// 79 on my youtube channel. Put in your values and then

// uncomment the code below. Don't use my values, you have

// to measure your own for it to work.

// float xMax= 1.03;

// float xMin= -.97;

// float yMax= .98;

// float yMin= -1.01;

// float zMax=.96 ;

// float zMin= -1.08;

// float xOffset = (xMax+xMin)/2;

// float yOffset = (yMax+yMin)/2;

// float zOffset = (zMax+zMin)/2;

// float xScale = 2/(xMax -xMin);

// float yScale = 2/(yMax - yMin);

// float zScale = 2/(zMax -zMin);

float roll;

float pitch;

Adafruit_MPU6050 mpu;

void setup() {

// put your setup code here, to run once:

Serial.begin(115200);

mpu.begin();

Serial.println("MPU6050 Started!");

mpu.setAccelerometerRange(MPU6050_RANGE_2_G);

mpu.setFilterBandwidth(MPU6050_BAND_21_HZ);

}

void loop() {

// put your main code here, to run repeatedly:

sensors_event_t a, g, temp;

mpu.getEvent(&a, &g, &temp);

Ax=a.acceleration.x/9.81;

Ay=a.acceleration.y/9.81;

Az=a.acceleration.z/9.81;

//Uncomment these lines of code to do the callibration

//This will only work if you have measured your max

//and min values, and put them in at the top of the code

// Ax = xScale*(Ax-xOffset);

// Ay = yScale*(Ay-yOffset);

// Az = zScale*(Az-zOffset);

pitch = atan2(Ay,sqrt(Az*Az+Ax*Ax))*360/(2*3.14);

roll = atan2(Ax,sqrt(Az*Az+Ay*Ay))*360/(2*3.14);

Serial.print("Roll:");

Serial.print(roll);

Serial.print(',');

Serial.print("Pitch:");

Serial.print(pitch);

Serial.print(',');

Serial.print("UL:");

Serial.print(90);

Serial.print(',');

Serial.print("LL:");

Serial.println(-90);

// Serial.print("Ax:");

// Serial.print(Ax);

// Serial.print(',');

// Serial.print("Ay:");

// Serial.print(Ay);

// Serial.print(',');

// Serial.print("Az:");

// Serial.print(Az);

// Serial.print(',');

// Serial.print("UL:");

// Serial.print(1);

// Serial.print(',');

// Serial.print("LL:");

// Serial.println(-1);

delay(50);

}

MicroPython, Raspberry Pi Pico, Tutorial

Getting UTC Atomic Clock Time and Date from GPS and Raspberry Pi Pico W

August 4, 2025 admin

In this video lesson we show how you can get extremely accurate time reference from your Adafruit Ultimate GPS V3. We show that atomic clock time is encoded in the NMEA sentences, and is in UTC. We show how to retrieve the data, and convert to your local time. In this video I compensated for the clock rolling from one day to the next, for positive UTC correction time, but did not account for clock rollover for negative UTC correction times. Also, several pointed out that you have to also compensate for calendar rollover at the end of the month, and the end of the year. The video shows how we are approaching the problem, and then the code below includes the compensations we did not do in the video. The code is heavily commented so hopefully you will be able to follow it.

Pi Pico GPS — Schematic for our GPS Tracker with OLED Display

For your convenience, the code developed in the lesson is presented below:

from machine import Pin, I2C, UART
import time
import _thread
from ssd1306 import SSD1306_I2C
# This is my utc correction. You need to look yours
# up for your location
utcCorrect = 3

i2c2 = I2C(1, sda=Pin(2), scl=Pin(3), freq=400000)
dsp = SSD1306_I2C(128, 64, i2c2)

dataLock = _thread.allocate_lock()
keepRunning = True
GPS = UART(1, baudrate=9600, tx=machine.Pin(8), rx=machine.Pin(9))
# The following line ensures that the GPS reports the GPVTG NMEA Sentence
GPS.write(b"$PMTK314,0,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n")
NMEAdata = {
    'GPGGA': "",
    'GPGSA': "",
    'GPRMC': "",
    'GPVTG': ""
}
GPSdata = {
    'latDD': 0,
    'lonDD': 0,
    'heading': 0,
    'fix': False,
    'sats': 0,
    'knots': 0,
    'time': '00:00:00',
    'date': '00/00/0000'
}

def gpsThread():
    print("Thread Running")
    global keepRunning, NMEAdata
    GPGGA = ""
    GPGSA = ""
    GPRMC = ""
    GPVTG = ""
    while not GPS.any():
        pass
    while GPS.any():
        junk = GPS.read()
        print(junk)
    myNMEA = ""
    while keepRunning:
        if GPS.any():
            myChar = GPS.read(1).decode('utf-8')
            myNMEA = myNMEA + myChar
            if myChar == '\n':
                myNMEA = myNMEA.strip()
                if myNMEA[1:6] == "GPGGA":
                    GPGGA = myNMEA
                if myNMEA[1:6] == "GPGSA":
                    GPGSA = myNMEA
                if myNMEA[1:6] == "GPRMC":
                    GPRMC = myNMEA
                if myNMEA[1:6] == "GPVTG":
                    GPVTG = myNMEA
                if GPGGA != "" and GPGSA != "" and GPRMC != "" and GPVTG != "":
                    dataLock.acquire()
                    NMEAdata = {
                        'GPGGA': GPGGA,
                        'GPGSA': GPGSA,
                        'GPRMC': GPRMC,
                        'GPVTG': GPVTG
                    }
                    dataLock.release()
                myNMEA = ""
    print("Thread Terminated Cleanly")

def parseGPS():
    readFix = int(NMEAmain['GPGGA'].split(',')[6])
    if readFix != 0:
        GPSdata['fix'] = True
        latRAW = NMEAmain['GPGGA'].split(',')[2]
        latDD = int(latRAW[0:2]) + float(latRAW[2:]) / 60
        if NMEAmain['GPGGA'].split(',')[3] == 'S':
            latDD = -latDD
        GPSdata['latDD'] = latDD
        lonRAW = NMEAmain['GPGGA'].split(',')[4]
        lonDD = int(lonRAW[0:3]) + float(lonRAW[3:]) / 60
        if NMEAmain['GPGGA'].split(',')[5] == 'W':
            lonDD = -lonDD
        GPSdata['lonDD'] = lonDD
        heading = float(NMEAmain['GPRMC'].split(',')[8])
        GPSdata['heading'] = heading
        knots = float(NMEAmain['GPRMC'].split(',')[7])
        GPSdata['knots'] = knots
        sats = int(NMEAmain['GPGGA'].split(',')[7])
        GPSdata['sats'] = sats
        utcTime = NMEAmain['GPGGA'].split(',')[1]
        utcDate = NMEAmain['GPRMC'].split(',')[9]
        # utcTime = "013445.000"
        # utcDate = "010125"

        # Extract year from UTC date (format: DDMMYY), prepend '20' for full year (e.g., '25' → '2025')
        myYear = '20' + utcDate[4:]
        # Extract month from UTC date (e.g., '01' for January)
        myMonth = utcDate[2:4]
        # Extract day from UTC date (e.g., '01' for 1st)
        myDay = utcDate[0:2]
        # Calculate hours by adding UTC offset to UTC hours, convert to string
        myHours = str(int(utcTime[0:2]) + utcCorrect)
        # Extract minutes from UTC time (e.g., '34' from '013445.000')
        myMin = utcTime[2:4]
        # Extract seconds from UTC time (e.g., '45' from '013445.000')
        mySec = utcTime[4:6]

        # Define array of maximum days per month (index 0-11 for months 1-12: Jan to Dec)
        maxDays = ['31', '28', '31', '30', '31', '30', '31', '31', '30', '31', '30', '31']

        # Check if year is a leap year (simplified: divisible by 4); if so, set February to 29 days
        if int(myYear) % 4 == 0:
            maxDays[1] = '29'

        # Check if hours exceed 24 (for positive UTC offsets, e.g., UTC 22:00 + 5 = 27:00)
        if int(myHours) >= 24:
            # Subtract 24 from hours to wrap around to next day (e.g., 27 → 3)
            myHours = str(int(myHours) - 24)
            # Pad hours with leading zero if single digit (e.g., '3' → '03')
            if len(myHours) < 2:
                myHours = '0' + myHours
            # Increment day to account for crossing midnight (e.g., 30 → 31)
            myDay = str(int(myDay) + 1)
            # Check if day exceeds maximum days for the current month (e.g., June 31 > 30)
            if int(myDay) > int(maxDays[int(myMonth) - 1]):
                # Reset day to 1 for the next month
                myDay = '01'
                # Increment month (e.g., June → July)
                myMonth = str(int(myMonth) + 1)
                # Check if month exceeds 12 (e.g., December → January)
                if int(myMonth) > 12:
                    # Reset month to January
                    myMonth = '01'
                    # Increment year (e.g., 2025 → 2026)
                    myYear = str(int(myYear) + 1)
            # Pad day with leading zero if single digit (e.g., '1' → '01')
            if len(myDay) < 2:
                myDay = '0' + myDay
            # Pad month with leading zero if single digit (e.g., '7' → '07')
            if len(myMonth) < 2:
                myMonth = '0' + myMonth

        # Check if hours are negative (for negative UTC offsets, e.g., UTC 01:00 - 5 = -4)
        if int(myHours) < 0:
            # Add 24 to hours to wrap around to previous day (e.g., -4 → 20)
            myHours = str(int(myHours) + 24)
            # Pad hours with leading zero if single digit (e.g., '3' → '03')
            if len(myHours) < 2:
                myHours = '0' + myHours
            # Decrement day to account for crossing midnight backward (e.g., 01 → 00)
            myDay = str(int(myDay) - 1)
            # Check if day is less than 1 (e.g., January 1 → December 31)
            if int(myDay) < 1:
                # Decrement month (e.g., January → December)
                myMonth = str(int(myMonth) - 1)
                # Check if month is less than 1 (e.g., January → December of previous year)
                if int(myMonth) < 1:
                    # Set month to December
                    myMonth = '12'
                    # Decrement year (e.g., 2025 → 2024)
                    myYear = str(int(myYear) - 1)
                # Set day to maximum days of the new month (e.g., December → 31)
                myDay = maxDays[int(myMonth) - 1]
            # Pad day with leading zero if single digit (e.g., '1' → '01')
            if len(myDay) < 2:
                myDay = '0' + myDay
            # Pad month with leading zero if single digit (e.g., '7' → '07')
            if len(myMonth) < 2:
                myMonth = '0' + myMonth

        # Combine hours, minutes, seconds into time string (e.g., '20:34:45')
        myTime = myHours + ':' + myMin + ':' + mySec
        # Combine month, day, year into date string (e.g., '12/31/2024')
        myDate = myMonth + '/' + myDay + '/' + myYear
        # Store local time in GPSdata dictionary
        GPSdata['time'] = myTime
        # Store local date in GPSdata dictionary
        GPSdata['date'] = myDate

def dispOLED():
    dsp.fill(0)
    if GPSdata['fix'] == False:
        dsp.text("Waiting for a fix . . .", 0, 0)
    if GPSdata['fix'] == True:
        dsp.text(GPSdata['date'][0:5] + ' ' + GPSdata['time'], 0, 0)
        dsp.text("LAT: " + str(GPSdata['latDD']), 0, 16)
        dsp.text("LON: " + str(GPSdata['lonDD']), 0, 26)
        dsp.text("SATS: " + str(GPSdata['sats']), 0, 56)
        dsp.text("SPEED: " + str(GPSdata['knots']) + ' Knts', 0, 36)
        dsp.text("HEAD: " + str(GPSdata['heading']) + 'deg.', 0, 46)
    dsp.show()

_thread.start_new_thread(gpsThread, ())
time.sleep(3)
try:
    while True:
        dataLock.acquire()
        NMEAmain = NMEAdata.copy()
        dataLock.release()
        parseGPS()
        if GPSdata['fix'] == False:
            print("Waiting for Fix . . .")
        if GPSdata['fix'] == True:
            print("Ultimate GPS Tracker Report: ")
            print(GPSdata['time'], GPSdata['date'])
            print("Lat and Lon: ", GPSdata['latDD'], GPSdata['lonDD'])
            print("Knots: ", GPSdata['knots'])
            print("Heading: ", GPSdata['heading'])
            print("Sats: ", GPSdata['sats'])
            print()
        dispOLED()
        time.sleep(1)

except KeyboardInterrupt:
    print("\nStopping Program . . . Cleaning Up UART")
    keepRunning = False
    time.sleep(1)
    GPS.deinit()
    time.sleep(1)
    dsp.fill(0)
    dsp.show()
    print("Exited Cleanly")

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from machine import Pin, I2C, UART

import time

import _thread

from ssd1306 import SSD1306_I2C

# This is my utc correction. You need to look yours

# up for your location

utcCorrect = 3

i2c2 = I2C(1, sda=Pin(2), scl=Pin(3), freq=400000)

dsp = SSD1306_I2C(128, 64, i2c2)

dataLock = _thread.allocate_lock()

keepRunning = True

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

# The following line ensures that the GPS reports the GPVTG NMEA Sentence

GPS.write(b"$PMTK314,0,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n")

NMEAdata = {

'GPGGA': "",

'GPGSA': "",

'GPRMC': "",

'GPVTG': ""

}

GPSdata = {

'latDD': 0,

'lonDD': 0,

'heading': 0,

'fix': False,

'sats': 0,

'knots': 0,

'time': '00:00:00',

'date': '00/00/0000'

}

def gpsThread():

print("Thread Running")

global keepRunning, NMEAdata

GPGGA = ""

GPGSA = ""

GPRMC = ""

GPVTG = ""

while not GPS.any():

pass

while GPS.any():

junk = GPS.read()

print(junk)

myNMEA = ""

while keepRunning:

if GPS.any():

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

myNMEA = myNMEA + myChar

if myChar == '\n':

myNMEA = myNMEA.strip()

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

GPGGA = myNMEA

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

GPGSA = myNMEA

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

GPRMC = myNMEA

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

GPVTG = myNMEA

if GPGGA != "" and GPGSA != "" and GPRMC != "" and GPVTG != "":

dataLock.acquire()

NMEAdata = {

'GPGGA': GPGGA,

'GPGSA': GPGSA,

'GPRMC': GPRMC,

'GPVTG': GPVTG

}

dataLock.release()

myNMEA = ""

print("Thread Terminated Cleanly")

def parseGPS():

readFix = int(NMEAmain['GPGGA'].split(',')[6])

if readFix != 0:

GPSdata['fix'] = True

latRAW = NMEAmain['GPGGA'].split(',')[2]

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

if NMEAmain['GPGGA'].split(',')[3] == 'S':

latDD = -latDD

GPSdata['latDD'] = latDD

lonRAW = NMEAmain['GPGGA'].split(',')[4]

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

if NMEAmain['GPGGA'].split(',')[5] == 'W':

lonDD = -lonDD

GPSdata['lonDD'] = lonDD

heading = float(NMEAmain['GPRMC'].split(',')[8])

GPSdata['heading'] = heading

knots = float(NMEAmain['GPRMC'].split(',')[7])

GPSdata['knots'] = knots

sats = int(NMEAmain['GPGGA'].split(',')[7])

GPSdata['sats'] = sats

utcTime = NMEAmain['GPGGA'].split(',')[1]

utcDate = NMEAmain['GPRMC'].split(',')[9]

# utcTime = "013445.000"

# utcDate = "010125"

# Extract year from UTC date (format: DDMMYY), prepend '20' for full year (e.g., '25' → '2025')

myYear = '20' + utcDate[4:]

# Extract month from UTC date (e.g., '01' for January)

myMonth = utcDate[2:4]

# Extract day from UTC date (e.g., '01' for 1st)

myDay = utcDate[0:2]

# Calculate hours by adding UTC offset to UTC hours, convert to string

myHours = str(int(utcTime[0:2]) + utcCorrect)

# Extract minutes from UTC time (e.g., '34' from '013445.000')

myMin = utcTime[2:4]

# Extract seconds from UTC time (e.g., '45' from '013445.000')

mySec = utcTime[4:6]

# Define array of maximum days per month (index 0-11 for months 1-12: Jan to Dec)

maxDays = ['31', '28', '31', '30', '31', '30', '31', '31', '30', '31', '30', '31']

# Check if year is a leap year (simplified: divisible by 4); if so, set February to 29 days

if int(myYear) % 4 == 0:

maxDays[1] = '29'

# Check if hours exceed 24 (for positive UTC offsets, e.g., UTC 22:00 + 5 = 27:00)

if int(myHours) >= 24:

# Subtract 24 from hours to wrap around to next day (e.g., 27 → 3)

myHours = str(int(myHours) - 24)

# Pad hours with leading zero if single digit (e.g., '3' → '03')

if len(myHours) < 2:

myHours = '0' + myHours

# Increment day to account for crossing midnight (e.g., 30 → 31)

myDay = str(int(myDay) + 1)

# Check if day exceeds maximum days for the current month (e.g., June 31 > 30)

if int(myDay) > int(maxDays[int(myMonth) - 1]):

# Reset day to 1 for the next month

myDay = '01'

# Increment month (e.g., June → July)

myMonth = str(int(myMonth) + 1)

# Check if month exceeds 12 (e.g., December → January)

if int(myMonth) > 12:

# Reset month to January

myMonth = '01'

# Increment year (e.g., 2025 → 2026)

myYear = str(int(myYear) + 1)

# Pad day with leading zero if single digit (e.g., '1' → '01')

if len(myDay) < 2:

myDay = '0' + myDay

# Pad month with leading zero if single digit (e.g., '7' → '07')

if len(myMonth) < 2:

myMonth = '0' + myMonth

# Check if hours are negative (for negative UTC offsets, e.g., UTC 01:00 - 5 = -4)

if int(myHours) < 0:

# Add 24 to hours to wrap around to previous day (e.g., -4 → 20)

myHours = str(int(myHours) + 24)

# Pad hours with leading zero if single digit (e.g., '3' → '03')

if len(myHours) < 2:

myHours = '0' + myHours

# Decrement day to account for crossing midnight backward (e.g., 01 → 00)

myDay = str(int(myDay) - 1)

# Check if day is less than 1 (e.g., January 1 → December 31)

if int(myDay) < 1:

# Decrement month (e.g., January → December)

myMonth = str(int(myMonth) - 1)

# Check if month is less than 1 (e.g., January → December of previous year)

if int(myMonth) < 1:

# Set month to December

myMonth = '12'

# Decrement year (e.g., 2025 → 2024)

myYear = str(int(myYear) - 1)

# Set day to maximum days of the new month (e.g., December → 31)

myDay = maxDays[int(myMonth) - 1]

# Pad day with leading zero if single digit (e.g., '1' → '01')

if len(myDay) < 2:

myDay = '0' + myDay

# Pad month with leading zero if single digit (e.g., '7' → '07')

if len(myMonth) < 2:

myMonth = '0' + myMonth

# Combine hours, minutes, seconds into time string (e.g., '20:34:45')

myTime = myHours + ':' + myMin + ':' + mySec

# Combine month, day, year into date string (e.g., '12/31/2024')

myDate = myMonth + '/' + myDay + '/' + myYear

# Store local time in GPSdata dictionary

GPSdata['time'] = myTime

# Store local date in GPSdata dictionary

GPSdata['date'] = myDate

def dispOLED():

dsp.fill(0)

if GPSdata['fix'] == False:

dsp.text("Waiting for a fix . . .", 0, 0)

if GPSdata['fix'] == True:

dsp.text(GPSdata['date'][0:5] + ' ' + GPSdata['time'], 0, 0)

dsp.text("LAT: " + str(GPSdata['latDD']), 0, 16)

dsp.text("LON: " + str(GPSdata['lonDD']), 0, 26)

dsp.text("SATS: " + str(GPSdata['sats']), 0, 56)

dsp.text("SPEED: " + str(GPSdata['knots']) + ' Knts', 0, 36)

dsp.text("HEAD: " + str(GPSdata['heading']) + 'deg.', 0, 46)

dsp.show()

_thread.start_new_thread(gpsThread, ())

time.sleep(3)

try:

while True:

dataLock.acquire()

NMEAmain = NMEAdata.copy()

dataLock.release()

parseGPS()

if GPSdata['fix'] == False:

print("Waiting for Fix . . .")

if GPSdata['fix'] == True:

print("Ultimate GPS Tracker Report: ")

print(GPSdata['time'], GPSdata['date'])

print("Lat and Lon: ", GPSdata['latDD'], GPSdata['lonDD'])

print("Knots: ", GPSdata['knots'])

print("Heading: ", GPSdata['heading'])

print("Sats: ", GPSdata['sats'])

print()

dispOLED()

time.sleep(1)

except KeyboardInterrupt:

print("\nStopping Program . . . Cleaning Up UART")

keepRunning = False

time.sleep(1)

GPS.deinit()

time.sleep(1)

dsp.fill(0)

dsp.show()

print("Exited Cleanly")

Arduino

Using Arduino to Calibrate the MPU6050 Accelerometers

July 31, 2025 admin

In this video lesson we show you how to calibrate the accelerometers on the MPU6050. You will have to find the min and max accelerometer numbers for your particular board, but I show you how in the video. Below, we show the schematic of how our circuit is connected.

In the lesson we developed the following code. Measure your min and max values of the three accelerometers according to the instructions in the video. Then enter those numbers in the code below, and un-comment out the commented lines. If you run the code as-is below, it should work, but the results will be uncalibrated and not as accurate as possible.

#include <Adafruit_MPU6050.h>
#include <Adafruit_Sensor.h>
#include <Wire.h>
float Ax;
float Ay;
float Az;

// If You want Calibrated results, you must rotate
// your board to all possible orientations, and 
// record your velues of xMax, xMin, yMax, yMin
// zMax, zMin. I show you how to do that in LESSON
// 79 on my youtube channel. Put in your values and then
// uncomment the code below. Don't use my values, you have
// to measure your own for it to work.

// float xMax= 1.03;
// float xMin= -.97;
// float yMax= .98;
// float yMin= -1.01;
// float zMax=.96 ;
// float zMin= -1.08;

// float xOffset = (xMax+xMin)/2;
// float yOffset = (yMax+yMin)/2;
// float zOffset = (zMax+zMin)/2;

// float xScale = 2/(xMax -xMin);
// float yScale = 2/(yMax - yMin);
// float zScale = 2/(zMax -zMin);

Adafruit_MPU6050 mpu;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  mpu.begin();
  Serial.println("MPU6050 Started!");
  mpu.setAccelerometerRange(MPU6050_RANGE_2_G);
  mpu.setFilterBandwidth(MPU6050_BAND_21_HZ);


}

void loop() {
  // put your main code here, to run repeatedly:
  sensors_event_t a, g, temp;
  mpu.getEvent(&a, &g, &temp);
  Ax=a.acceleration.x/9.81;
  Ay=a.acceleration.y/9.81;
  Az=a.acceleration.z/9.81;

//Uncomment these lines of code to do the callibration
//This will only work if you have measured your max
//and min values, and put them in at the top of the code
  // Ax = xScale*(Ax-xOffset);
  // Ay = yScale*(Ay-yOffset);
  // Az = zScale*(Az-zOffset);

  Serial.print("Ax:");
  Serial.print(Ax);
  Serial.print(',');
  Serial.print("Ay:");
  Serial.print(Ay);
  Serial.print(',');
    Serial.print("Az:");
  Serial.print(Az);
  Serial.print(',');
 Serial.print("UL:");
 Serial.print(1);
 Serial.print(',');
 Serial.print("LL:");
 Serial.println(-1);

  delay(50);

}

#include <Adafruit_MPU6050.h>

#include <Adafruit_Sensor.h>

#include <Wire.h>

float Ax;

float Ay;

float Az;

// If You want Calibrated results, you must rotate

// your board to all possible orientations, and

// record your velues of xMax, xMin, yMax, yMin

// zMax, zMin. I show you how to do that in LESSON

// 79 on my youtube channel. Put in your values and then

// uncomment the code below. Don't use my values, you have

// to measure your own for it to work.

// float xMax= 1.03;

// float xMin= -.97;

// float yMax= .98;

// float yMin= -1.01;

// float zMax=.96 ;

// float zMin= -1.08;

// float xOffset = (xMax+xMin)/2;

// float yOffset = (yMax+yMin)/2;

// float zOffset = (zMax+zMin)/2;

// float xScale = 2/(xMax -xMin);

// float yScale = 2/(yMax - yMin);

// float zScale = 2/(zMax -zMin);

Adafruit_MPU6050 mpu;

void setup() {

// put your setup code here, to run once:

Serial.begin(115200);

mpu.begin();

Serial.println("MPU6050 Started!");

mpu.setAccelerometerRange(MPU6050_RANGE_2_G);

mpu.setFilterBandwidth(MPU6050_BAND_21_HZ);

}

void loop() {

// put your main code here, to run repeatedly:

sensors_event_t a, g, temp;

mpu.getEvent(&a, &g, &temp);

Ax=a.acceleration.x/9.81;

Ay=a.acceleration.y/9.81;

Az=a.acceleration.z/9.81;

//Uncomment these lines of code to do the callibration

//This will only work if you have measured your max

//and min values, and put them in at the top of the code

// Ax = xScale*(Ax-xOffset);

// Ay = yScale*(Ay-yOffset);

// Az = zScale*(Az-zOffset);

Serial.print("Ax:");

Serial.print(Ax);

Serial.print(',');

Serial.print("Ay:");

Serial.print(Ay);

Serial.print(',');

Serial.print("Az:");

Serial.print(Az);

Serial.print(',');

Serial.print("UL:");

Serial.print(1);

Serial.print(',');

Serial.print("LL:");

Serial.println(-1);

delay(50);

}

Technology Tutorials

Applying a Low Pass Filter to Roll and Pitch Calculations on the MPU6050

Getting Altitude Data from the GPS NMEA Sentences

Using Arduino to Calculate Roll and Pitch from MPU6050 3-axis Accelerometers

Getting UTC Atomic Clock Time and Date from GPS and Raspberry Pi Pico W

Using Arduino to Calibrate the MPU6050 Accelerometers

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