diff --git a/Asus_Chromebook_Flip_C101PA.md b/Asus_Chromebook_Flip_C101PA.md
index 57b6995..2c98705 100644
--- a/Asus_Chromebook_Flip_C101PA.md
+++ b/Asus_Chromebook_Flip_C101PA.md
@@ -11,3 +11,12 @@ ALSA_CONFIG_UCM=/opt/alsa/ucm alsaucm -c rk3399-gru-sound set _verb HiFi
 ```
 
 Note that the port will display as "Headphones" despite using the speakers.  When paired with pulseaudio and pulseaudio-alsa, be aware that the full volume range is addressed through levels 0-9 of the Master volume control.  Levels 10-100 provide no additional gain.
+
+## Backlight control
+Add this udev rule at `/etc/udev/rules.d/backlight.rules`, and add your user to the `video` group.
+
+```
+SUBSYSTEM=="backlight",RUN+="/usr/bin/chgrp video /sys/class/backlight/%k/brightness /sys/class/backlight/%k/bl_power",RUN+="/usr/bin/chmod 664 /sys/class/backlight/%k/brightness /sys/class/backlight/%k/bl_power"
+```
+
+This will allow you to change the backlight brightness by writing values from 0 to 65535 to `/sys/class/backlight/backlight/brightness`.