No such file or directory: '/dev/gpiochip0'

CAP 33

I installed the module python-periphery to use the GPIO, but there is a problem when calling.

>>> from periphery import GPIO
>>> GPIO("/dev/gpiochip0", 11, "out")
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/periphery/gpio.py", line 355, in _open
    self._chip_fd = os.open(path, 0)
FileNotFoundError: [Errno 2] No such file or directory: '/dev/gpiochip0'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.6/site-packages/periphery/gpio.py", line 338, in __init__
    self._open(path, line, direction)
  File "/usr/lib/python3.6/site-packages/periphery/gpio.py", line 357, in _open
    raise GPIOError(e.errno, "Opening GPIO chip: " + e.strerror)
periphery.gpio.GPIOError: [Errno 2] Opening GPIO chip: No such file or directory

crispyoz

@CAP-33 Why would you not use onion-gpio-sysfs, I'm not sure periphery is supported on OpenWrt, but I may be wrong. But it's python so ....

CAP 33

@crispyoz
look here
https://community.onion.io/topic/3591/python3-modules-for-gpio-and-serial-port/9?_=1584647234098

crispyoz

@CAP-33 Maybe Lazar has some advice then.

My advice is to use a real programing language

Lazar Demin

@CAP-33 what firmware are you running? Here's what I see on a device on v0.3.2 b232:

# ls /dev/gpio*
/dev/gpiochip0  /dev/gpiochip1  /dev/gpiochip2

We've generally used the sysfs gpio interface: https://www.kernel.org/doc/html/latest/admin-guide/gpio/sysfs.html

But I've just learned that sysfs has been deprecated since linux 4.8 and that descriptor-based access (through /dev/gpiochipN) is the new way to go (see article here) ...

CAP 33

@Lazar-Demin
v0.2.1 b198

ls /dev/gpio*
ls: /dev/gpio*: No such file or directory

crispyoz

@CAP-33 wouldn't the logical conclusion be that your first step would be to upgrade to the latest firmware?