Asus Zenbook Duo screenpad brightness control on linux

asus-brightness-down

# /etc/acpi/events/asus-keyboard-backlight-up
# This is called when the user presses the key brightness 
# up button and calls /etc/acpi/asus-keyboard-backlight.sh for
# further processing.

# sudo ln -s /path/to/file /etc/acpi/events/asus-brightness-down

event=video/brightnessdown BRTDN 00000087 00000000
action=/etc/acpi/asus-brightness.sh

asus-brightness-up

# /etc/acpi/events/asus-keyboard-backlight-up
# This is called when the user presses the key brightness 
# up button and calls /etc/acpi/asus-keyboard-backlight.sh for
# further processing.

# sudo ln -s /path/to/file /etc/acpi/events/asus-brightness-up

event=video/brightnessup BRTUP 00000086 00000000
action=/etc/acpi/asus-brightness.sh

asus-brightness.sh

#!/bin/bash

DEC_BRIGHTNESS=$(cat /sys/class/backlight/intel_backlight/brightness)
DEC_BRIGHTNESS=$(echo "$DEC_BRIGHTNESS * 0.64" | bc)
DEC_BRIGHTNESS=$(echo "${DEC_BRIGHTNESS%.*}")
HEX_BRIGHTNESS=$(printf '%02x' $DEC_BRIGHTNESS)

echo $HEX_BRIGHTNESS > /home/MYUSER/temp.log

if [ $(cat /home/MYUSER/zbpd14/dual) -eq 1 ]
then
	if [ $DEC_BRIGHTNESS -eq 256 ]
	then
		echo "MAX BRIGHTNESS $DEC_BRIGHTNESS"
		echo "\_SB.ATKD.WMNB 0x0 0x53564544 b32000500FF000000" | sudo tee /proc/acpi/call
	else
		echo "NOT MAX BRIGHTNESS $DEC_BRIGHTNESS"
		echo "\_SB.ATKD.WMNB 0x0 0x53564544 b32000500${HEX_BRIGHTNESS}000000" | sudo tee /proc/acpi/call
	fi
fi

# sudo ln -s /path/to/file /etc/acpi/asus-brightness.sh

Modified version of: https://github.com/njm2015/zbpd14 thanks to @njm2015