How can i fix error 121 remote i/o error with mpu6050 on raspberry pi model 3 b ROS

Question

I have issues on my mpu6050. I'm using a project called DextroBot on github as base for my final project. The problem is, that as soon as I run the roslaunch I'm get an error called remote I/O error.

I don't know if it has something to do with the code but just in case this is the code.

#!/usr/bin/env python

'''
        Read Gyro and Accelerometer by Interfacing Raspberry Pi with MPU6050 using Python
'''
import smbus            #import SMBus module of I2C
from time import sleep          #import
import math
import rospy
from sensor_msgs.msg import Imu
from tf.transformations import quaternion_from_euler
import time

#some MPU6050 Registers and their Address
PWR_MGMT_1   = 0x6B
SMPLRT_DIV   = 0x19
CONFIG       = 0x1A
GYRO_CONFIG  = 0x1B
INT_ENABLE   = 0x38
ACCEL_XOUT_H = 0x3B
ACCEL_YOUT_H = 0x3D
ACCEL_ZOUT_H = 0x3F
GYRO_XOUT_H  = 0x43
GYRO_YOUT_H  = 0x45
GYRO_ZOUT_H  = 0x47

# useful constants 
M_PI = 3.14159265358979323846

# init ROS publisher
pub = rospy.Publisher('imu', Imu, queue_size=10)
rospy.init_node('imu_sense', anonymous=True)


def MPU_Init():
    #write to sample rate register
    bus.write_byte_data(Device_Address, SMPLRT_DIV, 7)
    
    #Write to power management register
    bus.write_byte_data(Device_Address, PWR_MGMT_1, 1)
    
    #Write to Configuration register
    bus.write_byte_data(Device_Address, CONFIG, 0)
    
    #Write to Gyro configuration register
    bus.write_byte_data(Device_Address, GYRO_CONFIG, 24)
    
    #Write to interrupt enable register
    bus.write_byte_data(Device_Address, INT_ENABLE, 1)


def read_raw_data(addr):
    #Accelero and Gyro value are 16-bit
        high = bus.read_byte_data(Device_Address, addr)
        low = bus.read_byte_data(Device_Address, addr+1)
    
        #concatenate higher and lower value
        value = ((high << 8) | low)
        
        #to get signed value from mpu6050
        if(value > 32768):
                value = value - 65536
        return value


def publish_imu(roll, pitch, yaw, Ax, Ay, Az):
    
    # compose the message
    sensor_imu = Imu()
    sensor_imu.header.frame_id = "dextrobot_imu_link"
    sensor_imu.header.stamp = rospy.Time.now()

    # convert from degrees to radians
    roll = roll * M_PI/180
    pitch = pitch * M_PI/180
    yaw = yaw * M_PI/180

    q = quaternion_from_euler(roll, pitch, yaw)

    sensor_imu.orientation.x = q[0]
    sensor_imu.orientation.y = q[1]
    sensor_imu.orientation.z = q[2]
    sensor_imu.orientation.w = q[3]
    sensor_imu.linear_acceleration.x = float(Ax)
    sensor_imu.linear_acceleration.y = float(Ay)
    sensor_imu.linear_acceleration.z = float(Az)

    # publish the composed message
    pub.publish(sensor_imu)


bus = smbus.SMBus(1)    # or bus = smbus.SMBus(0) for older version boards
Device_Address = 0x68   # MPU6050 device address

MPU_Init()

if __name__ == '__main__':
    yaw = 0.0
    print (" Reading Data of Gyroscope and Accelerometer")

    while not rospy.is_shutdown():
        
        #Read Accelerometer raw value
        acc_x = read_raw_data(ACCEL_XOUT_H)
        acc_y = read_raw_data(ACCEL_YOUT_H)
        acc_z = read_raw_data(ACCEL_ZOUT_H)
        
        #Read Gyroscope raw value
        gyro_x = read_raw_data(GYRO_XOUT_H)
        gyro_y = read_raw_data(GYRO_YOUT_H)
        gyro_z = read_raw_data(GYRO_ZOUT_H)
        
        #Full scale range +/- 250 degree/C as per sensitivity scale factor
        Ax = acc_x/16384.0
        Ay = acc_y/16384.0
        Az = acc_z/16384.0
        
        Gx = gyro_x/131.0
        Gy = gyro_y/131.0
        Gz = gyro_z/131.0

        # Calculate Pitch & Roll
        pitch = -(math.atan2(Ax, math.sqrt(Ay*Ay + Az*Az))*180.0)/M_PI
        roll = (math.atan2(Ay, Az)*180.0)/M_PI
            
        # Ignore the gyro if our angular velocity does not meet our threshold
        if (Gz > 1 or Gz < -1):
            Gz /= 20
            yaw += Gz

        # Keep our angle between 0-359 degrees
        if (yaw < 0):
            yaw += 360
        elif (yaw > 359):
            yaw -= 360
        
        publish_imu(roll, pitch, yaw, Ax, Ay, Az)

I tried changing the smbus line that says 0 for older boards. The thing is that nothing worked cause I'm using the i2c bus 1 not the 0, so fixing this is gonna be hard. I didn't soddered all the pins cause I only need to use 4, the leds on the mpu6050 don't turn on so I have no clue of what is going on. The computer I'm using is a raspberry pi 3 model b

Maybe this helps: https://stackoverflow.com/questions/52735862/getting-ioerror-errno-121-remote-i-o-error-with-smbus-on-python-raspberry-w — Fruchtzwerg, Feb 04 '23 at 16:25

Combinacijus · Answer 1 · 2023-03-11T19:40:54.373

Couple of suggestions:

Double check wiring. Led not working might be sign that MPU6050 don't get power (or it might be led that blinks during data transfer depends on design)
Make sure Device_Address = 0x68 is actually IMU address. You can check it with arduino I2cScanner.
Make sure I2C is configured correctly on RPi in sudo raspi-config configurator
Double check if bus = smbus.SMBus(1) is correct.
If it still doesn't work test it on arduino and follow some well known tutorial. If it doesn't work even on arduino then IMU might be broken.

How can i fix error 121 remote i/o error with mpu6050 on raspberry pi model 3 b ROS

1 Answers1