alex-mous / MPU6050-C-CPP-Library-for-Raspberry-Pi

A library for using the MPU6050 accelerometer and gyroscope module with Raspberry Pi to get both raw values and filtered angles on all axes

MPU6050 Accelerometer and Gyroscope C++ library

Description

    This is a basic control library for using the MPU6050 accelerometer and gyroscope module with Raspberry Pi using i2c protocol
    It provides functions to read raw accelerometer data and fully corrected (with complementary filters and some logic) angles on any axis (roll, pitch, yaw)

Installation

The dependencies for this library are libi2c-dev, i2c-tools, and libi2c0. These can be installed with apt. The latest version of this code now works on Raspbian Buster. Note: to run the code, you will need to enable I2C in raspi-config.

Function Definitions

    

__constructor__ (MPU6050)

        args:
            int8_t addr - the address of the MPU6050 (usually 0x68; can find with command "i2cdetect -y 1" (may need to be installed - run "sudo apt-get install i2c-tools -y")
        description:
            sets up i2c device and starts loop to read the angle
    

getAccelRaw

        args:
            float *x - pointer to the variable where the X axis results should be stored
            float *y - pointer to the variable where the Y axis results should be stored
            float *z - pointer to the variable where the Z axis results should be stored
        description:
            gets the raw accelerometer values from the MPU6050 registers
    

getAccel

        args:
            float *x - pointer to the variable where the X axis results should be stored
            float *y - pointer to the variable where the Y axis results should be stored
           &nbpfloat *z - pointer to the variable where the Z axis results should be stored
        description:
            gets the accelerometer values (in g), rounded to three decimal places
    

getGyroRaw

        args:
            float *roll - pointer to the variable where the roll (X) axis results should be stored
            float *pitch - pointer to the variable where the pitch (Y) axis results should be stored
            float *yaw - pointer to the variable where the yaw (Z) axis results should be stored
        description:
            gets the raw gyroscope values from the MPU6050 registers
 nbsp  

getGyro

        args:
            float *roll - pointer to the variable where the roll (X) axis results should be stored
            float *pitch - pointer to the variable where the pitch (Y) axis results should be stored
            float *yaw - pointer to the variable where the yaw (Z) axis results should be stored
        description:
            gets the gyroscope values (in degrees/second)
    

getOffsets

        args:
            float *ax_off - pointer to the variable where the accelerometer x axis offset will be stored
         &nsp  float *ay_off - pointer to the variable where the accelerometer y axis offset will be stored
            float *az_off - pointer to the variable where the accelerometer z axis offset will be stored
            float *gr_off - pointer to the variable where the gyroscope roll axis offset will be stored
            float *gp_off - pointer to the variable where the gyroscope pitch axis offset will be stored
            float *gy_off - pointer to the variable where the gyroscope yaw axis offset will be stored
        description:
            finds the offsets needed
            before running, place the module on a completely flat surface (check with a sirit level if possible) and make sure that it stays still while running this function, the results will be stored in the variables ax_off, ay_off, az_off, gr_off, gp_off, gy_off for accel x offset... and gyro roll offset..., take these values and put them into the MPU6050.h file (A_OFF_X, A_OFF_Y, A_OFF_Z, G_OFF_X, G_OFF_Y and G_OFF_Z)
    

getAngle

        args:
            int axis - which axis to use (0 for roll (x), 1 for pitch (Y) and 2 for yaw (Z))
            float *results - pointer to the variable where the angle will be stored
        description:
            gets the current combined (accelerometer and gyroscope) angle
            NOTE: the yaw axis will return 0 unless 'calc_yaw' i set to true - See Parameters

Parameters:

    

calc_yaw

        type:
            bool
        description:
            set this to true when you want to calculate the angle around the yaw axis (remember to change this back to false after taking the yaw readings to prevent gyroscope drift)
            this is used to prevent drift because only the gyroscope is used to calculate the yaw rotation

Copyright (c) 2019, Alex Mous
Licensed under the Creative Commons Attribution-ShareAlike 4.0 International (CC-BY-4.0)