Toggle LED with push button

svanheule · August 13, 2020, 7:03am

The hardware.button wiki page lists KEY_LIGHTS_TOGGLE as one of the supported keys, for which I can add a script in /etc/rc.button/lights_toggle.

To disable the LED(s), I could probably just loop over all buttons and set trigger to 'none' and default to '0'. That would mean I lost all user config though, so I'll have a look at how to avoid that.

Edit: Found a similar use case for KEY_LIGHTS_TOGGLE

Edit:
DTS entry:

led {
	label = "LED button";
	linux,code = <KEY_LIGHTS_TOGGLE>;
	gpios = <&gpio 21 GPIO_ACTIVE_LOW>;
	debounce-interval = <60>;
};

Button handler script for the TP-Link EAP225-Wall:

#!/bin/sh

[ "${ACTION}" = "released" ] || exit 0

LED_PATH="/sys/class/leds/tp-link:white:status/brightness"
CURRENT=$(cat $LED_PATH)
if [[ $CURRENT == 0 ]]; then
	echo 255 > $LED_PATH
else
	echo 0 > $LED_PATH
fi
return 0