Controlling Backlight

If there is an LCD present and connected to the system, the backlight brightness can be controlled by reading and writing to files in the /sys filesystem (sysfs).

# cd /sys/class/backlight/backlight
# cat max_brightness
100

The max_brightnessfile contains a value that pertains to the maximum brightness of the backlight. The brightness level can be controlled by writing a number between 0 and max_brightnessto the brightnessfile.

# cat brightness
50

Off:

# echo 0 > brightness 

50%:

# echo 50 > brightness

Maximum:

# echo 100 > brightness