2.2.9 MPU6050 Module

Introduction

The MPU-6050 is the world’s first and only 6-axis motion tracking devices (3-axis Gyroscope and 3-axis Accelerometer) designed for smartphones, tablets and wearable sensors that have these features, including the low power, low cost, and high performance requirements.

In this experiment, use I2C to obtain the values of the three-axis acceleration sensor and three-axis gyroscope for MPU6050 and display them on the screen.

Required Components

In this project, we need the following components.

It’s definitely convenient to buy a whole kit, here’s the link:

Name	ITEMS IN THIS KIT	LINK
Raphael Kit	337	Raphael Kit

You can also buy them separately from the links below.

COMPONENT INTRODUCTION	PURCHASE LINK
GPIO Extension Board	BUY
Breadboard	BUY
Jumper Wires	BUY
MPU6050 Module	BUY

Schematic Diagram

MPU6050 communicates with the microcontroller through the I2C bus interface. The SDA1 and SCL1 need to be connected to the corresponding pin.

Experimental Procedures

Step 1: Build the circuit.

Step 2: Setup I2C (see Appendix I2C Configuration. If you have set I2C, skip this step.)

Step 3: Go to the folder of the code.

cd ~/raphael-kit/python

Step 4: Run the executable file.

sudo python3 2.2.9_mpu6050.py

With the code run, the angle of deflection of the x-axis and y-axis and the acceleration, angular velocity on each axis read by MPU6050 will be printed on the screen after being calculating.

Note

• If you get the error FileNotFoundError: [Errno 2] No such file or directory: '/dev/i2c-1', you need to refer to I2C Configuration to enable the I2C.

• If you get ModuleNotFoundError: No module named 'smbus2' error, please run sudo pip3 install smbus2.

• If the error OSError: [Errno 121] Remote I/O error appears, it means the module is miswired or the module is broken.

Code

Note

You can Modify/Reset/Copy/Run/Stop the code below. But before that, you need to go to source code path like raphael-kit/python. After modifying the code, you can run it directly to see the effect.

import smbus
import math
import time

# Power management registers
power_mgmt_1 = 0x6b
power_mgmt_2 = 0x6c

def read_byte(adr):
    return bus.read_byte_data(address, adr)

def read_word(adr):
    high = bus.read_byte_data(address, adr)
    low = bus.read_byte_data(address, adr+1)
    val = (high << 8) + low
    return val

def read_word_2c(adr):
    val = read_word(adr)
    if (val >= 0x8000):
        return -((65535 - val) + 1)
    else:
        return val

def dist(a,b):
    return math.sqrt((a*a)+(b*b))

def get_y_rotation(x,y,z):
    radians = math.atan2(x, dist(y,z))
    return -math.degrees(radians)

def get_x_rotation(x,y,z):
    radians = math.atan2(y, dist(x,z))
    return math.degrees(radians)


bus = smbus.SMBus(1) # or bus = smbus.SMBus(1) for Revision 2 boards
address = 0x68       # This is the address value read via the i2cdetect command

# Now wake the 6050 up as it starts in sleep mode
bus.write_byte_data(address, power_mgmt_1, 0)

while True:
    time.sleep(0.1)
    gyro_xout = read_word_2c(0x43)
    gyro_yout = read_word_2c(0x45)
    gyro_zout = read_word_2c(0x47)

    print ("gyro_xout : ", gyro_xout, " scaled: ", (gyro_xout / 131))
    print ("gyro_yout : ", gyro_yout, " scaled: ", (gyro_yout / 131))
    print ("gyro_zout : ", gyro_zout, " scaled: ", (gyro_zout / 131))

    accel_xout = read_word_2c(0x3b)
    accel_yout = read_word_2c(0x3d)
    accel_zout = read_word_2c(0x3f)

    accel_xout_scaled = accel_xout / 16384.0
    accel_yout_scaled = accel_yout / 16384.0
    accel_zout_scaled = accel_zout / 16384.0

    print ("accel_xout: ", accel_xout, " scaled: ", accel_xout_scaled)
    print ("accel_yout: ", accel_yout, " scaled: ", accel_yout_scaled)
    print ("accel_zout: ", accel_zout, " scaled: ", accel_zout_scaled)

    print ("x rotation: " , get_x_rotation(accel_xout_scaled, accel_yout_scaled, accel_zout_scaled))
    print ("y rotation: " , get_y_rotation(accel_xout_scaled, accel_yout_scaled, accel_zout_scaled))

    time.sleep(1)

Code Explanation

def read_word(adr):
    high = bus.read_byte_data(address, adr)
    low = bus.read_byte_data(address, adr+1)
    val = (high << 8) + low
    return val

def read_word_2c(adr):
    val = read_word(adr)
    if (val >= 0x8000):
        return -((65535 - val) + 1)
    else:
        return val

Read sensor data sent from MPU6050.

def get_y_rotation(x,y,z):
    radians = math.atan2(x, dist(y,z))
    return -math.degrees(radians)

Calculate the deflection angle of the y-axis.

def get_x_rotation(x,y,z):
    radians = math.atan2(y, dist(x,z))
    return math.degrees(radians)

Calculate the deflection angle of the x-axis.

gyro_xout = read_word_2c(0x43)
gyro_yout = read_word_2c(0x45)
gyro_zout = read_word_2c(0x47)

print ("gyro_xout : ", gyro_xout, " scaled: ", (gyro_xout / 131))
print ("gyro_yout : ", gyro_yout, " scaled: ", (gyro_yout / 131))
print ("gyro_zout : ", gyro_zout, " scaled: ", (gyro_zout / 131))

Read the values of the x axis, y axis and z axis on the gyroscope sensor, convert the metadata to angular velocity values, and then print them.

accel_xout = read_word_2c(0x3b)
accel_yout = read_word_2c(0x3d)
accel_zout = read_word_2c(0x3f)

accel_xout_scaled = accel_xout / 16384.0
accel_yout_scaled = accel_yout / 16384.0
accel_zout_scaled = accel_zout / 16384.0

print ("accel_xout: ", accel_xout, " scaled: ", accel_xout_scaled)
print ("accel_yout: ", accel_yout, " scaled: ", accel_yout_scaled)
print ("accel_zout: ", accel_zout, " scaled: ", accel_zout_scaled)

Read the values of the x axis, y axis and z axis on the acceleration sensor, convert the elements to accelerated speed value (gravity unit), and print them.

print ("x rotation: " , get_x_rotation(accel_xout_scaled, accel_yout_scaled, accel_zout_scaled))
print ("y rotation: " , get_y_rotation(accel_xout_scaled, accel_yout_scaled, accel_zout_scaled))

Print the deflection angles of the x-axis and y-axis.

Phenomenon Picture