Adafruit MMA8451加速度计出现树莓派osError [Errno 121]远程I/O错误。

Question

我在树莓派 3 B+ 上运行 Python 3.5，并连接了一个显示器。

我的项目是使简单的加速度计打印其值。我正在按照以下 教程 进行操作：我甚至在 /boot/config.txt 的末尾添加了 dtoverlay=spi1-3cs 来激活另一个硬件 SPI 端口，因为我将我的 Pi 与显示器一起使用。

我想运行以下代码，但出现以下错误：

我已经运行了i2cdetect -y -1。它显示地址为 1d 的设备。

我已经检查了连接和一切，不确定我做错了什么。

    # Simple demo of reading the MMA8451 orientation every second.
# Author: Tony DiCola
import time

import board
import busio
import adafruit_mma8451
# Initialize I2C bus.
i2c = busio.I2C(board.SCL, board.SDA)

# Initialize MMA8451 module.
sensor = adafruit_mma8451.MMA8451(i2c)
# Optionally change the address if it's not the default:
##sensor = adafruit_mma8451.MMA8451(i2c, address=0x1d)

# Main loop to print the acceleration and orientation every second.
while True:
    x, y, z = sensor.acceleration
    print('Acceleration: x={0:0.3f}m/s^2 y={1:0.3f}m/s^2 z={2:0.3f}m/s^2'.format(x, y, z))
    orientation = sensor.orientation

    print('Orientation: ', end='')
    if orientation == adafruit_mma8451.PL_PUF:
        print('Portrait, up, front')
    elif orientation == adafruit_mma8451.PL_PUB:
        print('Portrait, up, back')
    elif orientation == adafruit_mma8451.PL_PDF:
        print('Portrait, down, front')
    elif orientation == adafruit_mma8451.PL_PDB:
        print('Portrait, down, back')
    elif orientation == adafruit_mma8451.PL_LRF:
        print('Landscape, right, front')
    elif orientation == adafruit_mma8451.PL_LRB:
        print('Landscape, right, back')
    elif orientation == adafruit_mma8451.PL_LLF:
        print('Landscape, left, front')
    elif orientation == adafruit_mma8451.PL_LLB:
        print('Landscape, left, back')
    time.sleep(1.0)

以下是错误信息：

错误如下：

Traceback (most recent call last):
  File "simpletest.py", line 15, in <module>
    sensor = adafruit_mma8451.MMA8451(i2c)
  File "/usr/local/lib/python3.5/dist-packages/adafruit_mma8451.py", line 103, in __init__
    while self._read_u8(_MMA8451_REG_CTRL_REG2) & 0x40 > 0:
  File "/usr/local/lib/python3.5/dist-packages/adafruit_mma8451.py", line 134, in _read_u8
    self._read_into(address, self._BUFFER, count=1)
  File "/usr/local/lib/python3.5/dist-packages/adafruit_mma8451.py", line 130, in _read_into
    in_end=count, stop=False)
  File "/usr/local/lib/python3.5/dist-packages/adafruit_bus_device/i2c_device.py", line 149, in write_then_readinto
    in_start=in_start, in_end=in_end, stop=stop)
  File "/home/pi/.local/lib/python3.5/site-packages/busio.py", line 68, in writeto_then_readfrom
    in_start=in_start, in_end=in_end, stop=stop)
  File "/home/pi/.local/lib/python3.5/site-packages/adafruit_blinka/microcontroller/generic_linux/i2c.py", line 63, in writeto_then_readfrom
    readin = self._i2c_bus.read_i2c_block_data(address, buffer_out[out_start:out_end][0], in_end-in_start)
  File "/home/pi/.local/lib/python3.5/site-packages/Adafruit_PureIO/smbus.py", line 215, in read_i2c_block_data
    ioctl(self._device.fileno(), I2C_RDWR, request)
OSError: [Errno 121] Remote I/O error

- Taha Arif

Answer 1

我在使用树莓派和加速度计时遇到了同样的问题——设备在使用命令时显示，但无法使用Adafruit的代码或命令获取数据。i2cdump命令显示出垃圾/损坏的数据。解决方法是树莓派和加速度计之间的接地线有问题。一旦修复了这个问题，设备就可以正确响应。

- CDJB