Thank you. Now it's working!!!

I add this rule to

/etc/udev/rules.d/99-input.rules

SUBSYSTEM=="input", ATTRS{name}=="button*", MODE="0660", ENV{ID_INPUT_KEY}="1", ENV{ID_INPUT_KEYBOARD}="1"

And now have GPIO key ID_INPUT_KEYBOARD parameter too.

pi@retropie:~ $ udevadm info --query all /dev/input/event1 P: /devices/platform/button@1a/input/input1/event1 N: input/event1 L: 0 S: input/by-path/platform-button@1a-event E: DEVPATH=/devices/platform/button@1a/input/input1/event1 E: DEVNAME=/dev/input/event1 E: MAJOR=13 E: MINOR=65 E: SUBSYSTEM=input E: USEC_INITIALIZED=28281822 E: ID_INPUT=1 E: ID_INPUT_KEY=1 E: ID_PATH=platform-button@1a E: ID_PATH_TAG=platform-button_1a E: LIBINPUT_DEVICE_GROUP=19/1/1:gpio-keys E: ID_INPUT_KEYBOARD=1 E: DEVLINKS=/dev/input/by-path/platform-button@1a-event E: TAGS=:power-switch:

Bidding hotkey to GPIO key is now working.

@buzz thank you for your response and sorry for posting on wrong forum. Cheers !

@craggus2000 Thanks for reporting back. Have fun. Please edit your first post and add in the something like [solved], so it is more likely to be picked up by search engines.

Your question made me updating my hint from last year on that topic.

Errata: 13 buttons do have 4 for the axis and 9 for the push buttons. :-D I was in a hurry.

@lolonois Good call. Now I know what the hotkeybtn is used for.

@mitu Excellent thank you!

@lolonois Thankyou very much. I will keep this in mind !

@mitu
When I tried using gpionext I kept being met with error messages. I ended up just getting a few different parts to work with the super pi girl drivers. Still, thank you for the help.

Thanks for your help. Between the documentation and the example, I have the button matrix somewhat working I think.

One more piece of the puzzle...at the end of my script, if I remove the GPIO.cleanup(), then the light stays on.

But, in subsequent calls to my script, I receive a warning that the channel is already in use. It doesn't stop the code, but the programmer in me doesn't like warnings.

My question now is why does the cleanup function change the output of the GPIO pins?

Take a look at https://github.com/recalbox/mk_arcade_joystick_rpi, it's similar to what you have in mind and it's already included in RetroPie.

Thanks. As soon as I posted here, I found this topic and with a bit of modification I was able to get it working. :)