fcntl.ioctl 不断导致 TimeoutError: [Errno 110] Connection timed out

Question

我正在运行 Ubuntu 22.0.4 的 Arduino Portenta x8 上制作程序。该程序的一部分有一个线程紧密轮询板上的 GPIO 引脚以读取线性执行器的编码器。我一直在为此使用 python-periphery，但我注意到在读取其他 GPIO 引脚时同时让另一个线程轮询编码器，几秒钟后我收到 TimeoutError: [Errno 110] Connection timed out。如果错误没有明确发生，我注意到有时引脚读数会导致随机值而不是输入的实际信号，就好像它们处于浮动状态一样。

我为测试这个问题写的测试代码如下：

from periphery import GPIO
import threading

def poll(gpio, num):
    while True:
        print("GPIO {num}: {gpio}".format(num=num, gpio=gpio.read()))

if __name__ =="__main__":
    gpio0 = GPIO("/dev/gpiochip5", 0, "in")
    gpio1 = GPIO("/dev/gpiochip5", 1, "in")
    # creating thread
    t1 = threading.Thread(target=poll, args=(gpio0,0,))
    t2 = threading.Thread(target=poll, args=(gpio1,1,))

    # starting thread 1
    t1.start()
    # starting thread 2
    t2.start()

    # wait until thread 1 is completely executed
    t1.join()
    # wait until thread 2 is completely executed
    t2.join()

    # both threads completely executed
    print("Done!")

完整错误信息如下：

Exception in thread Thread-2 (poll):
Traceback (most recent call last):
  File "/usr/local/lib/python3.10/dist-packages/periphery/gpio_cdev1.py", line 323, in read
Exception in thread Thread-1 (poll):
Traceback (most recent call last):
  File "/usr/local/lib/python3.10/dist-packages/periphery/gpio_cdev1.py", line 323, in read
    fcntl.ioctl(self._line_fd, Cdev1GPIO._GPIOHANDLE_GET_LINE_VALUES_IOCTL, data)
TimeoutError: [Errno 110] Connection timed out

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
    fcntl.ioctl(self._line_fd, Cdev1GPIO._GPIOHANDLE_GET_LINE_VALUES_IOCTL, data)
  File "/usr/lib/python3.10/threading.py", line 1016, in _bootstrap_inner
TimeoutError: [Errno 110] Connection timed out

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.10/threading.py", line 1016, in _bootstrap_inner
    self.run()
    self.run()
  File "/usr/lib/python3.10/threading.py", line 953, in run
  File "/usr/lib/python3.10/threading.py", line 953, in run
    self._target(*self._args, **self._kwargs)
    self._target(*self._args, **self._kwargs)
  File "/home/dev/wall_panels/bb_ws/src/spc_unit_tester/spc_unit_tester/polling_test.py", line 6, in poll
  File "/home/dev/wall_panels/bb_ws/src/spc_unit_tester/spc_unit_tester/polling_test.py", line 6, in poll
    print("GPIO {num}: {gpio}".format(num=num, gpio=gpio.read()))
  File "/usr/local/lib/python3.10/dist-packages/periphery/gpio_cdev1.py", line 325, in read
    print("GPIO {num}: {gpio}".format(num=num, gpio=gpio.read()))
  File "/usr/local/lib/python3.10/dist-packages/periphery/gpio_cdev1.py", line 325, in read
    raise GPIOError(e.errno, "Getting line value: " + e.strerror)
periphery.gpio.GPIOError: [Errno 110] Getting line value: Connection timed out
    raise GPIOError(e.errno, "Getting line value: " + e.strerror)
periphery.gpio.GPIOError: [Errno 110] Getting line value: Connection timed out
Done!

我尝试在每个循环的底部添加 time.sleep() ，并测试不同的睡眠值。具有较长的延迟（如 1 秒或 0.5 秒）似乎可以修复错误，但较短的延迟（如 0.02 秒（20 毫秒））会导致相同的错误。由于我需要轮询有一个短暂的延迟，以免错过任何编码器信号，我希望找到一些其他方法或解决方法来轮询此编码器信号（执行器供参考：https://www.firgelliauto.com/blogs /tutorials/synchronous-control-of-two-optical-linear-actuators-using-an-arduino).

任何帮助或想法将不胜感激，谢谢！