使用I2C连接AGX Xavier和MPU6050并读取IMU数据

硬件设置

NVIDIA Jetson AGX Xavier GPIO Header Pinout

Pin1位置：

MPU6050:

连接：

MPU6050	Jetson Nano
VCC	$pin 4 (5V)
GND	pin 6 (GND)
SCL	pin 28 (SCL)
SDA	pin 27 (SDA)

通信协议

实用I2C进行通信，详情见 I2C serial communication protocol

打开Jetson Nano，打开终端页面

sudo i2cdetect -r -y 1

可以看到，MPU6050的地址是68

代码

使用Adafruit Circuit Python Library

安装adafruit-blinka库

sudo apt-get update
pip3 install adafruit-blinka

新建文件夹mpu6050_test

mkdir mpu6050_test
cd mpu6050_test

创建py文件blinkatest.py

gedit blinkatest.py

blinkatest.py：

import board
import busio
 
print("Hello blinka!")
 
# Try to create an I2C device
i2c = busio.I2C(board.SCL, board.SDA)
print("I2C 1 ok!")
 
print("done!")

运行代码，检测是否成功通信

python3 blinkatest.py

若无误，安装mpu6050库

pip3 install adafruit-circuitpython-mpu6050

创建py文件mpu6050_simpletest.py

gedit mpu6050_simpletest.py

mpu6050_simpletest.py：

import time
import board
import adafruit_mpu6050

i2c = board.I2C()  # uses board.SCL and board.SDA
mpu = adafruit_mpu6050.MPU6050(i2c)

while True:
    print("Acceleration: X:%.2f, Y: %.2f, Z: %.2f m/s^2" % (mpu.acceleration))
    print("Gyro X:%.2f, Y: %.2f, Z: %.2f rad/s" % (mpu.gyro))
    print("Temperature: %.2f C" % mpu.temperature)
    print("")
    time.sleep(1)

运行代码，此时应已经可以正常通信

python3 mpu6050_simpletest.py

使用smbus

安装smbus库

sudo apt-get install python3-smbus

创建py文件mpu6050_simpletest2.py

gedit mpu6050_simpletest2.py

mpu6050_simpletest2.py：

'''Read Gyro and Accelerometer by Interfacing Raspberry Pi with MPU6050 using Python
    http://www.electronicwings.com
'''
import smbus            #import SMBus module of I2C
from time import sleep          #import
 
#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
 
 
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
 
 
bus = smbus.SMBus(1)    # or bus = smbus.SMBus(0) for older version boards
Device_Address = 0x68   # MPU6050 device address
 
MPU_Init()
 
print (" Reading Data of Gyroscope and Accelerometer")

while True:
     
    #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
     
 
    print ("Gx=%.2f" %Gx, u'\u00b0'+ "/s", "\tGy=%.2f" %Gy, u'\u00b0'+ "/s", "\tGz=%.2f" %Gz, u'\u00b0'+ "/s", "\tAx=%.2f g" %Ax, "\tAy=%.2f g" %Ay, "\tAz=%.2f g" %Az)     
    sleep(0.01)

运行

python3 mpu6050_simpletest2.py