MPU9250 Arduino Simple Code

Introduction

MPU9250 Simple code

NOTE: MPU9250 is 3.3V device, so it might break if connected wrong. Double check that Arduino's +5 V is on VCC. Doublecheck that SCL and SCA are on the Analog inputs, and do not push current into those pins. See more at https://electronics.stackexchange.com/questions/492792/does-the-mpu9250-require-a-5-to-3-3-v-level-shifter-when-used-with-arduino-uno

NOTE: delay() do not work with MPU9250.h used below!

Some MPU9250 libaries for Arduino

• MPU9250 by hideakitai. Discontinued. Not more supported. https://github.com/hideakitai/MPU9250
• Bolder Flight Systems MPU9250 by Brian Taylor
• FaBo 202 9Axis MPU9250 by FaBo
• FastIMU by LiquidCGS. https://github.com/LiquidCGS/FastIMU
• I2C-Sensor-Lib iLib by Ingmar Splitt
• ICM20948_WE by Wolfgang
• MPU9250_asukiaaa by Asuki Kono

Use i2c_scanner (from Arduino IDE) to find out the address.

The IMUIndentiefier by FastIMU describes:

=========== IMU Identifier ===========
IMU Found: MPU6500 On address: 0x68
This IMU is capable of the following axis: 3A,3G
This IMU is supported by the FastIMU library.
======================================

thought the board was supposed to be 9250.

The simple code

This is very similar to that given in https://github.com/hideakitai/MPU9250

Connect

• MPU0250 SDA -> A4
• MPU0250 SCL -> A5

Because of the 5V and 3.3V mismatch. The analog input works, though.

#include "MPU9250.h"

MPU9250 mpu;

void setup() {
    Serial.begin(115200);
    Wire.begin();
    delay(2000);

    if (!mpu.setup(0x68)) {  // change to your own address
        while (1) {
            Serial.println("MPU connection failed. Please check your connection with `connection_check` example.");
            delay(5000);
        }
    }
}

void loop() {
    if (mpu.update()) {
        static uint32_t prev_ms = millis();
        if (millis() > prev_ms + 25) {
            print_roll_pitch_yaw();
            prev_ms = millis();
        }
    }
}

void print_roll_pitch_yaw() {
    Serial.print("Yaw, Pitch, Roll: ");
    Serial.print(mpu.getYaw(), 2);
    Serial.print(", ");
    Serial.print(mpu.getPitch(), 2);
    Serial.print(", ");
    Serial.println(mpu.getRoll(), 2);
}

Error messages

• MPU connection failed. Please check your connection with `connection_check` example from the Library. Add there following lines (see https://forum.arduino.cc/t/problem-to-connect-to-my-mpu9250/700295/4)
  • If that gives 0x70, the IMU is MPU6500 instead of MPU9250.

        byte ca = readByte(addrs[i], WHO_AM_I_MPU9250);

        Serial.print( "The WHO_AM_I byte is: 0x");   // <- added
        Serial.println( (int) ca, HEX);         // <- added

        if (ca == MPU9250_WHOAMI_DEFAULT_VALUE) {

Code 2

Simple, given by Fabo

/**
 Original: @file read9axis.ino 
 @brief This is an Example for the FaBo 9Axis I2C Brick. 
 http://fabo.io/202.html
 Released under APACHE LICENSE, VERSION 2.0
 @author FaBo<info@fabo.io>
*/

#include <Wire.h>
#include <FaBo9Axis_MPU9250.h>

FaBo9Axis fabo_9axis;

void setup() {
  Serial.begin(115200);
  Serial.println("RESET");
  Serial.println();

  Serial.println("configuring device.");

  if (fabo_9axis.begin()) {
    Serial.println("configured FaBo 9Axis I2C Brick");
  } else {
    Serial.println("device error");
    while(1);
  }
}

void loop() {
  float ax,ay,az;

  fabo_9axis.readAccelXYZ(&ax,&ay,&az);

  Serial.print("ax: ");
  Serial.print(ax);
  Serial.print(" ay: ");
  Serial.print(ay);
  Serial.print(" az: ");
  Serial.println(az);

  delay(1000);
}

Code 2b

Add temperature and other data.

/**
 Original: @file read9axis.ino 
 @brief This is an Example for the FaBo 9Axis I2C Brick. 
 http://fabo.io/202.html
 Released under APACHE LICENSE, VERSION 2.0
 @author FaBo<info@fabo.io>
*/

#include <Wire.h>
#include <FaBo9Axis_MPU9250.h>

FaBo9Axis fabo_9axis;

void setup() {
  Serial.begin(115200);
  Serial.println("RESET");
  Serial.println();

  Serial.println("configuring device.");

  if (fabo_9axis.begin()) {
    Serial.println("configured FaBo 9Axis I2C Brick");
  } else {
    Serial.println("device error");
    while(1);
  }
}

void loop() {
  float ax,ay,az;
  float gx,gy,gz;
  float mx,my,mz;
  float temp;

  fabo_9axis.readAccelXYZ(&ax,&ay,&az);
  fabo_9axis.readGyroXYZ(&gx,&gy,&gz);
  fabo_9axis.readMagnetXYZ(&mx,&my,&mz);
  fabo_9axis.readTemperature(&temp);

  Serial.print("ax: ");
  Serial.print(ax);
  Serial.print(" ay: ");
  Serial.print(ay);
  Serial.print(" az: ");
  Serial.println(az);

  Serial.print("gx: ");
  Serial.print(gx);
  Serial.print(" gy: ");
  Serial.print(gy);
  Serial.print(" gz: ");
  Serial.println(gz);

  Serial.print("mx: ");
  Serial.print(mx);
  Serial.print(" my: ");
  Serial.print(my);
  Serial.print(" mz: ");
  Serial.println(mz);

  Serial.print("temp: ");
  Serial.println(temp);

  delay(1000);
}

Code 3: Implement delay()

#include "MPU9250.h"

MPU9250 mpu;

const int buzzer = 9; //buzzer to arduino pin 9

void setup(){
  pinMode(buzzer, OUTPUT); // Set buzzer - pin 9 as an output
  Serial.begin(115200);
  Wire.begin();
  delay(2000);

  if (!mpu.setup(0x68)) {  // change to your own address
      while (1) {
          Serial.println("MPU connection failed. Please check your connection with `connection_check` example.");
          delay(5000);
      }
  } 
}

int fi = 100;

void loop(){

    if (mpu.update()) {
        static uint32_t prev_ms = millis();
        if (millis() > prev_ms + 25) {
            print_roll_pitch_yaw();
            prev_ms = millis();
        }
    }
  
    tone(buzzer, fi); // Send sound signal...
    static uint32_t prev_ms_sound = millis();
    if (millis() > prev_ms_sound + 100) {
      noTone(buzzer);
      fi += 100;    
      prev_ms_sound = millis();
      if (fi > 10000){
        fi = 100;
      }
    }

}

Code MPU6050 The smaller

Code from https://www.arduinolearning.com/code/arduino-mpu6500-6-axis-motion-tracking-device.php

#include "Wire.h"
#include "I2Cdev.h"
#include "MPU6050.h"

MPU6050 accelgyro;

int16_t ax, ay, az;
int16_t gx, gy, gz;

#define LED_PIN 13
bool blinkState = false;

void setup() {
  Wire.begin();
  Serial.begin(38400);

  Serial.println("Initializing I2C devices...");
  accelgyro.initialize();

  Serial.println("Testing device connections...");
  Serial.println(accelgyro.testConnection() ? "MPU6050 connection successful" : "MPU6050 connection failed");

  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  accelgyro.getMotion6(&ax, &ay, &az, &gx, &gy, &gz);

  Serial.print(ax); Serial.print("\t");
  Serial.print(ay); Serial.print("\t");
  Serial.println(az); Serial.print("\t");

  // blink LED to indicate activity
  blinkState = !blinkState;
  digitalWrite(LED_PIN, blinkState);
}