RE: GPIO trouble

-----Original Message----- From: Guillaume Gardet Sent: 16 September 2021 10:01 To: Peter Suetterlin ; arm@lists.opensuse.org Cc: Matthias Brugger Subject: RE: GPIO trouble

Hi,

...

-----Original Message----- From: Peter Suetterlin Sent: 15 September 2021 17:52 To: arm@lists.opensuse.org Subject: GPIO trouble

Hi list,

slowly trying to get known with my Pi 4 running Tumbleweed. I added a fan, and wanted to control it via GPIO. But I fail to actually control the pins :(

I was trying to follow this description: https://howchoo.com/g/ote2mjkzzta/control-raspberry-pi-fan-temperature - python that uses GIOP17. So I installed the needed 'gpiozero' python package using pip.

Trying the command 'pinout' that is part of it results in an error:

Unable to initialize GPIO Zero. This usually means that you are not running pinout on a Raspberry Pi. If you still wish to run pinout, set the GPIOZERO_PIN_FACTORY environment variable to 'mock' and retry, or refer to the Remote GPIO section of the manual* to configure your environment to remotely access your Pi.

So I export GPIOZERO_PIN_FACTORY=mock, then I get a pinout listed, I can run python, and with from gpiozero import OutputDevice fan = OutputDevice(17) I can use fan.on(), fan.off() or fan.value to set/read the state. Just the pin doesn't do anything, it always stays low :(

So I wanted to get most basic and tried echo 17 > /sys/class/gpio/export but that gave me only "write error: Invalid argument"

Indeed the directory only lists Pi4:~ # ls /sys/class/gpio export gpiochip446 gpiochip454 unexport

which suggests lowest GPIO available is 446!?

What am I missing?

Did you have a look at https://en.opensuse.org/openSUSE:GPIO for standard packages to access GPIO instead of downstream, RPi specific, software?

You can use 'gpioinfo gpiochip446' and 'gpioinfo gpiochip454' to get info about the gpio available.

You can try to use an offset of 446, so try to set gpio 463 (446 + 17). Not sure why there is such an offset, though. Matthias, any idea?

And latest released Tumbleweed (20210901) test in openQA shows gpiochips 0 and 1: gpiochip0 [pinctrl-bcm2711] (58 lines) gpiochip1 [raspberrypi-exp-gpio] (8 lines) See: https://openqa.opensuse.org/tests/1898134#step/libgpiod/14

Cheers, Guillaume