ASUS_Q325U_Debian.md

Keyboard Backlight

• Create a new system directory:

if [ ! -e "/usr/lib/systemd/system" ] ; then 
mkdir /usr/lib/systemd/system
fi

• Create new service:

/usr/lib/systemd/system/asus-kbd-backlight.service

[Unit]
Description=Asus Keyboard Backlight
Wants=systemd-backlight@leds:asus::kbd_backlight.service
After=systemd-backlight@leds:asus::kbd_backlight.service

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/chmod 666 /sys/class/leds/asus::kbd_backlight/brightness

[Install]
WantedBy=multi-user.target

• Create controller script

#!/bin/bash

path="/sys/class/leds/asus::kbd_backlight"
#path="/sys/class/leds/asus\:\:kbd_backlight"

# max should be 3
max=$(cat ${path}/max_brightness)
# step: represent the difference between previous and next brightness
step=1
previous=$(cat ${path}/brightness)

function commit {
	if [[ $1 = [0-9]* ]]
	then 
		if [[ $1 -gt $max ]]
		then 
			next=$max
		elif [[ $1 -lt 0 ]]
		then 
			next=0
		else 
			next=$1
		fi
		echo $next >> ${path}/brightness
		exit 0
	else 
		exit 1
	fi
}

case "$1" in
 up)
     commit $(($previous + $step))
  ;;
 down)
     commit $(($previous - $step))
  ;;
 max)
	 commit $max
  ;;
 on)
	 $0 max
  ;;
 off)
	 commit 0
  ;;
 show)
	 echo $previous
  ;;
 night)
	 commit 1 
	 ;;
 allowusers)
	 # Allow members of users group to change brightness
	 sudo chgrp users ${path}/brightness
	 sudo chmod g+w ${path}/brightness
  ;;
 disallowusers)
	 # Allow members of users group to change brightness
	 sudo chgrp root ${path}/brightness
	 sudo chmod g-w ${path}/brightness
  ;;
 *)
	 commit	$1
esac

exit 0