USB gamepad and GPIO hotkey

mgrunt

Hi,
I'm using USB gamepad and I want use separate hotkey (to view retroarch menu) connect to GPIO.

I defined GPIO key in /boot/config.txt
dtoverlay=gpio-key,gpio=26,label="KEY_ESC",keycode=1

When I run evtest i get this (key escape is working):

Available devices:
/dev/input/event0: USB gamepad
/dev/input/event1: button@1a
/dev/input/event2: ADS7846 Touchscreen
Select the device event number [0-2]: 1
Input driver version is 1.0.1
Input device ID: bus 0x19 vendor 0x1 product 0x1 version 0x100
Input device name: "button@1a"
Supported events:
Event type 0 (EV_SYN)
Event type 1 (EV_KEY)
Event code 1 (KEY_ESC)
Properties:
Testing ... (interrupt to exit)
Event: time 1630670854.319443, type 1 (EV_KEY), code 1 (KEY_ESC), value 1
Event: time 1630670854.319443, -------------- SYN_REPORT ------------
Event: time 1630670854.449281, type 1 (EV_KEY), code 1 (KEY_ESC), value 0
Event: time 1630670854.449281, -------------- SYN_REPORT ------------

But I still don't know how to configure
\\retropie\configs\all\retroarch.cfg

I tried some combinations of parameter settings

input_enable_hotkey_btn
input_enable_hotkey

But nothing works.

When I enter to the retroarch menu (Main menu - Settings - Input - Hotkey Binds - Hotkeys), changing the hotkey does not work. It does not respond at all to pressing the GPIO key. How to do it?

Thanks

mitu

What does the following command show ?

udevadm info  --query all /dev/input/event1

mgrunt

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=28639720
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: DEVLINKS=/dev/input/by-path/platform-button@1a-event
E: TAGS=:power-switch:

mitu

RetroArch may be ignoring the inputs from your GPIO - see https://github.com/libretro/RetroArch/pull/12830 for context.

mgrunt

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.