In this video lesson we show you how to calibrate the QMC5883L 3-axis magnetometer. The lesson is geared toward this specific magnetometer, but the procedure will be the same for any 3-axis magnetometer. We then use the calibrated reading to measure and calculate the magnetic heading of the device. With this, we have created a calibrated digital compass. In this lesson we are using the GY-87 module, which contains the QMC5883L magnetometer. We are connecting the module to the arduino using the following schematic:

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

In the video we develop two programs. The first program determines your sensor’s calibration constants. Then the second program uses those calibration constants to calculate heading, or yaw. The second program uses the offsets and scale parameters for MY PARTICULAR SENSOR. These values were determined using the first program. You must determine these values for your sensor, and then edit the second program to use your particular calibration parameters.

Program to determine your calibration parameters:

#include <Adafruit_MPU6050.h>
#include <Adafruit_Sensor.h>
#include <Wire.h>
#include <QMC5883LCompass.h>
int x, y, z;
int xMax = -10000;
int xMin = 10000;
int yMax = -10000;
int yMin = 10000;
int zMax = -10000;
int zMin = 10000;
float xOffset, xScale, yOffset, yScale, zOffset, zScale;
Adafruit_MPU6050 mpu;
QMC5883LCompass compass;
void setup() {
  Serial.begin(115200);
  mpu.begin();
  mpu.setI2CBypass(true);
  compass.init();
}
void loop() {
  compass.read();
  x = compass.getX();
  y = compass.getY();
  z = compass.getZ();
  if (x > xMax) {
    xMax = x;
  }
  if (x < xMin) {
    xMin = x;
  }
  if (y>yMax){
    yMax=y;
  }
  if (y<yMin){
    yMin=y;
  }
  if (z > zMax) {
    zMax = z;
  }
  if (z < zMin) {
    zMin = z;
  }
  xOffset = (xMax + xMin) / 2.;
  yOffset = (yMax + yMin) / 2.;
  zOffset = (zMax + zMin) / 2.;
  xScale = 2. / (xMax - xMin);
  yScale = 2. / (yMax - yMin);
  zScale = 2. / (zMax - zMin);
  Serial.print(x);
  Serial.print(',');
  Serial.print(y);
  Serial.print(',');
  Serial.print(z);
    Serial.print(',');
  Serial.print(xMax);
  Serial.print(',');
  Serial.print(xMin);
  Serial.print(',');
  Serial.print(yMax);
  Serial.print(',');
  Serial.print(yMin);
  Serial.print(',');
  Serial.print(zMax);
  Serial.print(',');
  Serial.print(zMin);
  Serial.print(',');
  Serial.print(xOffset);
  Serial.print(',');
  Serial.print(yOffset);
  Serial.print(',');
  Serial.print(zOffset);
  Serial.print(',');
  Serial.print(xScale,5);
  Serial.print(',');
  Serial.print(yScale,5);
  Serial.print(',');
  Serial.println(zScale,5);
  delay(100);
}

#include <Adafruit_MPU6050.h>

#include <Adafruit_Sensor.h>

#include <Wire.h>

#include <QMC5883LCompass.h>

int x, y, z;

int xMax = -10000;

int xMin = 10000;

int yMax = -10000;

int yMin = 10000;

int zMax = -10000;

int zMin = 10000;

float xOffset, xScale, yOffset, yScale, zOffset, zScale;

Adafruit_MPU6050 mpu;

QMC5883LCompass compass;

void setup() {

Serial.begin(115200);

mpu.begin();

mpu.setI2CBypass(true);

compass.init();

}

void loop() {

compass.read();

x = compass.getX();

y = compass.getY();

z = compass.getZ();

if (x > xMax) {

xMax = x;

}

if (x < xMin) {

xMin = x;

}

if (y>yMax){

yMax=y;

}

if (y<yMin){

yMin=y;

}

if (z > zMax) {

zMax = z;

}

if (z < zMin) {

zMin = z;

}

xOffset = (xMax + xMin) / 2.;

yOffset = (yMax + yMin) / 2.;

zOffset = (zMax + zMin) / 2.;

xScale = 2. / (xMax - xMin);

yScale = 2. / (yMax - yMin);

zScale = 2. / (zMax - zMin);

Serial.print(x);

Serial.print(',');

Serial.print(y);

Serial.print(',');

Serial.print(z);

Serial.print(',');

Serial.print(xMax);

Serial.print(',');

Serial.print(xMin);

Serial.print(',');

Serial.print(yMax);

Serial.print(',');

Serial.print(yMin);

Serial.print(',');

Serial.print(zMax);

Serial.print(',');

Serial.print(zMin);

Serial.print(',');

Serial.print(xOffset);

Serial.print(',');

Serial.print(yOffset);

Serial.print(',');

Serial.print(zOffset);

Serial.print(',');

Serial.print(xScale,5);

Serial.print(',');

Serial.print(yScale,5);

Serial.print(',');

Serial.println(zScale,5);

delay(100);

}

Once you get your calibration parameters, then put them into this program. This program will then calculate your compass heading:

#include <Adafruit_MPU6050.h>
#include <Adafruit_Sensor.h>
#include <Wire.h>
#include <QMC5883LCompass.h>
float x,y,z;
//The following numbers are for my particular sensor. You need
//to edit the following lines to put in your sensor calibration
//numbers
float xOffset=-382.5;
float yOffset=378.5;
float zOffset=1014.5;
float xScale = .00121;
float yScale=.00115;
float zScale=.00105;
float head;

Adafruit_MPU6050 mpu;
QMC5883LCompass compass;
void setup() {
Serial.begin(115200);
mpu.begin();
mpu.setI2CBypass(true);
compass.init();
}
void loop() {
 compass.read();
 x = (compass.getX()-xOffset)*xScale;
 y = (compass.getY()-yOffset)*yScale;
 z = (compass.getZ()-zOffset)*zScale;

// Serial.print(x);
// Serial.print(',');
// Serial.print(y);
// Serial.print(',');
// Serial.println(z);
head = atan2(y,x)*360/2/PI;
Serial.print("Heading: ");
Serial.println(head);
 delay(100);
}

#include <Adafruit_MPU6050.h>

#include <Adafruit_Sensor.h>

#include <Wire.h>

#include <QMC5883LCompass.h>

float x,y,z;

//The following numbers are for my particular sensor. You need

//to edit the following lines to put in your sensor calibration

//numbers

float xOffset=-382.5;

float yOffset=378.5;

float zOffset=1014.5;

float xScale = .00121;

float yScale=.00115;

float zScale=.00105;

float head;

Adafruit_MPU6050 mpu;

QMC5883LCompass compass;

void setup() {

Serial.begin(115200);

mpu.begin();

mpu.setI2CBypass(true);

compass.init();

}

void loop() {

compass.read();

x = (compass.getX()-xOffset)*xScale;

y = (compass.getY()-yOffset)*yScale;

z = (compass.getZ()-zOffset)*zScale;

// Serial.print(x);

// Serial.print(',');

// Serial.print(y);

// Serial.print(',');

// Serial.println(z);

head = atan2(y,x)*360/2/PI;

Serial.print("Heading: ");

Serial.println(head);

delay(100);

}

Arduino

Using the QMC5883L Magnetometers on the GY-87 Module

September 17, 2025 admin

In this video lesson we activate the QMC5883L 3-axis magnetometer on our GY-87 module. We show how to read the raw magnetic field strength in the x, y, and z axis. Your homework assignment will be to then calibrate the measurements such that you center the measured values around 0, and create a unit circle. This calibration will be very similar to what we did for the accelerometers a few weeks ago. This is the schematic we continue to use in this lesson:

This is the code we developed in todays lesson to read the raw data from the magnetometers.

#include <Adafruit_MPU6050.h>
#include <Adafruit_Sensor.h>
#include <Wire.h>
#include <QMC5883LCompass.h>
int x,y,z;
Adafruit_MPU6050 mpu;
QMC5883LCompass compass;
void setup() {
Serial.begin(115200);
mpu.begin();
mpu.setI2CBypass(true);
compass.init();
}
void loop() {
 compass.read();
 x = compass.getX();
 y = compass.getY();
 z = compass.getZ();
Serial.print(x);
Serial.print(',');
Serial.print(y);
Serial.print(',');
Serial.println(z);
 delay(100);
}

#include <Adafruit_MPU6050.h>

#include <Adafruit_Sensor.h>

#include <Wire.h>

#include <QMC5883LCompass.h>

int x,y,z;

Adafruit_MPU6050 mpu;

QMC5883LCompass compass;

void setup() {

Serial.begin(115200);

mpu.begin();

mpu.setI2CBypass(true);

compass.init();

}

void loop() {

compass.read();

x = compass.getX();

y = compass.getY();

z = compass.getZ();

Serial.print(x);

Serial.print(',');

Serial.print(y);

Serial.print(',');

Serial.println(z);

delay(100);

}

Python, Raspberry Pi Pico

Logging Data On Your Raspberry Pi Pico Using Flash Memory

September 17, 2025 admin

In this video lesson, We show you how to log sensor data on your Raspberry Pi Pico W. We will start with simple read and write functions, and then show you how to write and read files line by line, and keep a log of your sensor data.

Our first program is very simple, and just shows how to write a line of data, and read a line of data the the Pico’s flash memory. Here is the code we used in the video for the first simple example.

# This code writes three sensor readings as a comma-separated string to log.txt
# on the Pico W, then reads the file back and splits the string into a list.
# Purpose: Demonstrate basic file writing and reading in MicroPython using log.txt.

# Writing comma-delimited data to a file
sensorData = "25.5,26.0,24.8"  # Example temperature readings from three sensors
with open('log.txt', 'w') as file:  # Open log.txt in write mode ('w')
    file.write(sensorData)  # Write the comma-separated string to the file
print("Data written to log.txt")  # Confirm data was written

# Reading comma-delimited data
with open('log.txt', 'r') as file:  # Open log.txt in read mode ('r')
    content = file.read()  # Read the entire file as a string
    print("Raw data:", content)  # Print the raw string
    # Parse into a list
    values = content.split(',')  # Split the string at commas to create a list
    print("Parsed values:", values)  # Print the resulting list

# This code writes three sensor readings as a comma-separated string to log.txt

# on the Pico W, then reads the file back and splits the string into a list.

# Purpose: Demonstrate basic file writing and reading in MicroPython using log.txt.

# Writing comma-delimited data to a file

sensorData = "25.5,26.0,24.8" # Example temperature readings from three sensors

with open('log.txt', 'w') as file: # Open log.txt in write mode ('w')

file.write(sensorData) # Write the comma-separated string to the file

print("Data written to log.txt") # Confirm data was written

# Reading comma-delimited data

with open('log.txt', 'r') as file: # Open log.txt in read mode ('r')

content = file.read() # Read the entire file as a string

print("Raw data:", content) # Print the raw string

# Parse into a list

values = content.split(',') # Split the string at commas to create a list

print("Parsed values:", values) # Print the resulting list

In the second example, we show greater complexity by writing and reading a file, line by line. Each line contains comma delimited sensor data.

# This code writes three sets of sensor readings to log.txt on the Pico W,
# each set as a comma-separated line, overwriting previous content, then reads
# the file back line by line, splitting each line into a list.
# Purpose: Show how to log multiple data sets to log.txt and read them one line at a time.

# Writing one line at a time
readingsOne = ["25.5", "26.0", "24.8"]  # First set of sensor readings
readingsTwo = ["12.6", "62.5", "33.4"]  # Second set of sensor readings
readingsThree = ["19.8", "20.1", "21.3"]  # Third set of sensor readings
allReadings = [readingsOne, readingsTwo, readingsThree]  # Combine into a list of lists

with open('log.txt', 'w') as file:  # Open log.txt in write mode ('w')
    for readingSet in allReadings:  # Loop through each set of readings
        # ','.join(readingSet) converts the list (e.g., ["25.5", "26.0", "24.8"])
        # into a single string "25.5,26.0,24.8" with commas between values.
        # We need this because file.write() requires a string, not a list.
        line = ','.join(readingSet)
        file.write(line + '\n')  # Write the line to the file with a newline
print("Data written to log.txt")  # Confirm data was written

# Reading one line at a time
with open('log.txt', 'r') as file:  # Open log.txt in read mode ('r')
    print("Reading line by line:")
    for line in file:  # Loop through each line in the file
        # line.strip() removes leading/trailing whitespace, including '\n'
        # .split(',') splits the line at commas to create a list of values
        values = line.strip().split(',')
        print("Sensor readings:", values)  # Print the list of readings

# This code writes three sets of sensor readings to log.txt on the Pico W,

# each set as a comma-separated line, overwriting previous content, then reads

# the file back line by line, splitting each line into a list.

# Purpose: Show how to log multiple data sets to log.txt and read them one line at a time.

# Writing one line at a time

readingsOne = ["25.5", "26.0", "24.8"] # First set of sensor readings

readingsTwo = ["12.6", "62.5", "33.4"] # Second set of sensor readings

readingsThree = ["19.8", "20.1", "21.3"] # Third set of sensor readings

allReadings = [readingsOne, readingsTwo, readingsThree] # Combine into a list of lists

with open('log.txt', 'w') as file: # Open log.txt in write mode ('w')

for readingSet in allReadings: # Loop through each set of readings

# ','.join(readingSet) converts the list (e.g., ["25.5", "26.0", "24.8"])

# into a single string "25.5,26.0,24.8" with commas between values.

# We need this because file.write() requires a string, not a list.

line = ','.join(readingSet)

file.write(line + '\n') # Write the line to the file with a newline

print("Data written to log.txt") # Confirm data was written

# Reading one line at a time

with open('log.txt', 'r') as file: # Open log.txt in read mode ('r')

print("Reading line by line:")

for line in file: # Loop through each line in the file

# line.strip() removes leading/trailing whitespace, including '\n'

# .split(',') splits the line at commas to create a list of values

values = line.strip().split(',')

print("Sensor readings:", values) # Print the list of readings

In these first two examples, when we open the file as ‘w’, the existing data is erased and a new file is created. In the example below, we open an existing file, and show how to append new data to the existing file without erasing the old data.

# This code appends a new set of sensor readings to log.txt on the Pico W
# as a comma-separated line, checks if the file exists, and reads the file
# line by line to verify the append.
# Purpose: Demonstrate appending to log.txt, verifying file existence, and checking contents.

import os  # Import os module for file system operations

# Appending a new set of readings to the file
newReadings = ["30.1", "29.8", "31.0"]  # New set of sensor readings
try:
    with open('log.txt', 'a') as file:  # Open log.txt in append mode ('a')
        # ','.join(newReadings) converts the list (e.g., ["30.1", "29.8", "31.0"])
        # into a single string "30.1,29.8,31.0" with commas between values.
        # We need this because file.write() requires a string, not a list.
        line = ','.join(newReadings)
        file.write(line + '\n')  # Append the line with a newline
    print("Appended new readings to log.txt")  # Confirm data was appended
except OSError as e:
    print("Error appending to file:", e)  # Handle errors like full flash

# Read and print file to verify append
try:
    with open('log.txt', 'r') as file:  # Open log.txt in read mode ('r')
        print("Verifying log.txt contents line by line:")
        for line in file:  # Loop through each line in the file
            # line.strip() removes leading/trailing whitespace, including '\n'
            # .split(',') splits the line at commas to create a list of values
            values = line.strip().split(',')
            print("Sensor readings:", values)  # Print the list of readings
except OSError as e:
    print("Error reading file:", e)  # Handle errors like file not found

# This code appends a new set of sensor readings to log.txt on the Pico W

# as a comma-separated line, checks if the file exists, and reads the file

# line by line to verify the append.

# Purpose: Demonstrate appending to log.txt, verifying file existence, and checking contents.

import os # Import os module for file system operations

# Appending a new set of readings to the file

newReadings = ["30.1", "29.8", "31.0"] # New set of sensor readings

try:

with open('log.txt', 'a') as file: # Open log.txt in append mode ('a')

# ','.join(newReadings) converts the list (e.g., ["30.1", "29.8", "31.0"])

# into a single string "30.1,29.8,31.0" with commas between values.

# We need this because file.write() requires a string, not a list.

line = ','.join(newReadings)

file.write(line + '\n') # Append the line with a newline

print("Appended new readings to log.txt") # Confirm data was appended

except OSError as e:

print("Error appending to file:", e) # Handle errors like full flash

# Read and print file to verify append

try:

with open('log.txt', 'r') as file: # Open log.txt in read mode ('r')

print("Verifying log.txt contents line by line:")

for line in file: # Loop through each line in the file

# line.strip() removes leading/trailing whitespace, including '\n'

# .split(',') splits the line at commas to create a list of values

values = line.strip().split(',')

print("Sensor readings:", values) # Print the list of readings

except OSError as e:

print("Error reading file:", e) # Handle errors like file not found

Arduino

Improving MPU6050 IMU Arduino Project Performance with a Complimentary Filter

September 11, 2025 admin

In this video lesson I show you how you can improve the performance of your Arduino MPU6050 IMU Project by incorporating a complimentary filter. We will combine the roll and pitch calculations from the accelerometer and gyro into a fused result which allows us to enjoy the best of both worlds.

For your convenience, the code developed is presented below:

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

float Gx;
float Gy;
float Gz;

float rollG=0;
float pitchG=0;
float yawG=0;

float gyroXOffset=0;
float gyroYOffset=0;
float gyroZOffset=0;

int tStart = millis();

// 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 rollLP = 0;
float pitchLP = 0;

float rollRAW;
float pitchRAW;

float rollComp=0;
float pitchComp=0;

float deltaRoll=0;
float deltaPitch=0;

Adafruit_MPU6050 mpu;

void calibrateGyro(){
Serial.println("Calibrating the Gyro: Keep Completely Stationary");
delay(1000);
int i;
float sumX = 0;
float sumY = 0;
float sumZ = 0;
int numPoints=100;
for (i=0;i<numPoints;i=i+1){
  sensors_event_t a, g, temp;
  mpu.getEvent(&a, &g, &temp);
  sumX = sumX + g.gyro.x;
  sumY = sumY + g.gyro.y;
  sumZ = sumZ + g.gyro.z;
  delay(10);
}
gyroXOffset = sumX/numPoints;
gyroYOffset = sumY/numPoints;
gyroZOffset = sumZ/numPoints;

}

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.setGyroRange(MPU6050_RANGE_2000_DEG);
  mpu.setFilterBandwidth(MPU6050_BAND_21_HZ);
calibrateGyro();
tStart = millis();
}

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;

  Gx = g.gyro.x-gyroXOffset;
  Gy = -(g.gyro.y-gyroYOffset);
  Gz = g.gyro.z-gyroZOffset;

rollG = rollG + (millis() - tStart)/1000. * Gy *360./2./3.14;
pitchG = pitchG + (millis() - tStart)/1000. * Gx *360./2./3.14;
yawG = yawG + (millis() - tStart)/1000. * Gz *360./2./3.14;
deltaRoll=(millis() - tStart)/1000. * Gy *360./2./3.14;
deltaPitch=(millis() - tStart)/1000. * Gx *360./2./3.14;
tStart = millis();

  //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);

  pitchLP = .75 * pitchLP + .25 * pitchRAW;
  rollLP = .75 * rollLP + .25 * rollRAW;

  rollComp= .1*rollRAW + .9*(rollComp + deltaRoll);
  pitchComp= .1*pitchRAW +.9*(pitchComp +deltaPitch);

  Serial.print("rollComp:");
  Serial.print(rollComp);
  Serial.print(',');
  Serial.print("pitchComp:");
  Serial.print(pitchComp);
  Serial.print(',');
  Serial.print("yawG:");
  Serial.print(yawG);
  Serial.print(',');
  // Serial.print("rollComp:");
  // Serial.print(rollComp);
  // Serial.print(',');
  // Serial.print("pitchG:");
  // Serial.print(pitchG);
  // Serial.print(',');
  // Serial.print("yawG:");
  // Serial.print(yawG);
  // 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(1);
}

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#include <Adafruit_MPU6050.h>

#include <Adafruit_Sensor.h>

#include <Wire.h>

float Ax;

float Ay;

float Az;

float Gx;

float Gy;

float Gz;

float rollG=0;

float pitchG=0;

float yawG=0;

float gyroXOffset=0;

float gyroYOffset=0;

float gyroZOffset=0;

int tStart = millis();

// 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 rollLP = 0;

float pitchLP = 0;

float rollRAW;

float pitchRAW;

float rollComp=0;

float pitchComp=0;

float deltaRoll=0;

float deltaPitch=0;

Adafruit_MPU6050 mpu;

void calibrateGyro(){

Serial.println("Calibrating the Gyro: Keep Completely Stationary");

delay(1000);

int i;

float sumX = 0;

float sumY = 0;

float sumZ = 0;

int numPoints=100;

for (i=0;i<numPoints;i=i+1){

sensors_event_t a, g, temp;

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

sumX = sumX + g.gyro.x;

sumY = sumY + g.gyro.y;

sumZ = sumZ + g.gyro.z;

delay(10);

}

gyroXOffset = sumX/numPoints;

gyroYOffset = sumY/numPoints;

gyroZOffset = sumZ/numPoints;

}

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.setGyroRange(MPU6050_RANGE_2000_DEG);

mpu.setFilterBandwidth(MPU6050_BAND_21_HZ);

calibrateGyro();

tStart = millis();

}

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;

Gx = g.gyro.x-gyroXOffset;

Gy = -(g.gyro.y-gyroYOffset);

Gz = g.gyro.z-gyroZOffset;

rollG = rollG + (millis() - tStart)/1000. * Gy *360./2./3.14;

pitchG = pitchG + (millis() - tStart)/1000. * Gx *360./2./3.14;

yawG = yawG + (millis() - tStart)/1000. * Gz *360./2./3.14;

deltaRoll=(millis() - tStart)/1000. * Gy *360./2./3.14;

deltaPitch=(millis() - tStart)/1000. * Gx *360./2./3.14;

tStart = millis();

//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);

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

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

rollComp= .1*rollRAW + .9*(rollComp + deltaRoll);

pitchComp= .1*pitchRAW +.9*(pitchComp +deltaPitch);

Serial.print("rollComp:");

Serial.print(rollComp);

Serial.print(',');

Serial.print("pitchComp:");

Serial.print(pitchComp);

Serial.print(',');

Serial.print("yawG:");

Serial.print(yawG);

Serial.print(',');

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

// Serial.print(rollComp);

// Serial.print(',');

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

// Serial.print(pitchG);

// Serial.print(',');

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

// Serial.print(yawG);

// 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(1);

}

Arduino

Reducing Gyro Drift in MPU6050 IMU Arduino Project

September 11, 2025 admin

In this video lesson we learn how to reduce drift in our roll, pitch, and yaw from the MPU6050 IMU Arduino Project. We will be using the following schematic in today’s work.

This 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;

float Gx;
float Gy;
float Gz;

float rollG=0;
float pitchG=0;
float yawG=0;

float gyroXOffset=0;
float gyroYOffset=0;
float gyroZOffset=0;

int tStart = millis();

// 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 calibrateGyro(){
Serial.println("Calibrating the Gyro: Keep Completely Stationary");
delay(1000);
int i;
float sumX = 0;
float sumY = 0;
float sumZ = 0;
int numPoints=1000;
for (i=0;i<numPoints;i=i+1){
  sensors_event_t a, g, temp;
  mpu.getEvent(&a, &g, &temp);
  sumX = sumX + g.gyro.x;
  sumY = sumY + g.gyro.y;
  sumZ = sumZ + g.gyro.z;
  delay(10);
}
gyroXOffset = sumX/numPoints;
gyroYOffset = sumY/numPoints;
gyroZOffset = sumZ/numPoints;

}

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.setGyroRange(MPU6050_RANGE_2000_DEG);
  mpu.setFilterBandwidth(MPU6050_BAND_21_HZ);
calibrateGyro();
tStart = millis();
}

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;

  Gx = g.gyro.x-gyroXOffset;
  Gy = g.gyro.y-gyroYOffset;
  Gz = g.gyro.z-gyroZOffset;

rollG = rollG + (millis() - tStart)/1000. * Gy *360./2./3.14;
pitchG = pitchG + (millis() - tStart)/1000. * Gx *360./2./3.14;
yawG = yawG + (millis() - tStart)/1000. * Gz *360./2./3.14;
tStart = millis();

  //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("Gx:");
  Serial.print(Gx);
  Serial.print(',');
  Serial.print("Gy:");
  Serial.print(Gy);
  Serial.print(',');
  Serial.print("Gz:");
  Serial.print(Gz);
  Serial.print(',');
  Serial.print("rollG:");
  Serial.print(rollG);
  Serial.print(',');
  Serial.print("pitchG:");
  Serial.print(pitchG);
  Serial.print(',');
  Serial.print("yawG:");
  Serial.print(yawG);
  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(1);
}

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#include <Adafruit_MPU6050.h>

#include <Adafruit_Sensor.h>

#include <Wire.h>

float Ax;

float Ay;

float Az;

float Gx;

float Gy;

float Gz;

float rollG=0;

float pitchG=0;

float yawG=0;

float gyroXOffset=0;

float gyroYOffset=0;

float gyroZOffset=0;

int tStart = millis();

// 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 calibrateGyro(){

Serial.println("Calibrating the Gyro: Keep Completely Stationary");

delay(1000);

int i;

float sumX = 0;

float sumY = 0;

float sumZ = 0;

int numPoints=1000;

for (i=0;i<numPoints;i=i+1){

sensors_event_t a, g, temp;

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

sumX = sumX + g.gyro.x;

sumY = sumY + g.gyro.y;

sumZ = sumZ + g.gyro.z;

delay(10);

}

gyroXOffset = sumX/numPoints;

gyroYOffset = sumY/numPoints;

gyroZOffset = sumZ/numPoints;

}

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.setGyroRange(MPU6050_RANGE_2000_DEG);

mpu.setFilterBandwidth(MPU6050_BAND_21_HZ);

calibrateGyro();

tStart = millis();

}

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;

Gx = g.gyro.x-gyroXOffset;

Gy = g.gyro.y-gyroYOffset;

Gz = g.gyro.z-gyroZOffset;

rollG = rollG + (millis() - tStart)/1000. * Gy *360./2./3.14;

pitchG = pitchG + (millis() - tStart)/1000. * Gx *360./2./3.14;

yawG = yawG + (millis() - tStart)/1000. * Gz *360./2./3.14;

tStart = millis();

//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("Gx:");

Serial.print(Gx);

Serial.print(',');

Serial.print("Gy:");

Serial.print(Gy);

Serial.print(',');

Serial.print("Gz:");

Serial.print(Gz);

Serial.print(',');

Serial.print("rollG:");

Serial.print(rollG);

Serial.print(',');

Serial.print("pitchG:");

Serial.print(pitchG);

Serial.print(',');

Serial.print("yawG:");

Serial.print(yawG);

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(1);

}

Technology Tutorials

Calibrating a 3-Axis Magnetometer

Using the QMC5883L Magnetometers on the GY-87 Module

Logging Data On Your Raspberry Pi Pico Using Flash Memory

Improving MPU6050 IMU Arduino Project Performance with a Complimentary Filter

Reducing Gyro Drift in MPU6050 IMU Arduino Project

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