15

Is there a way to adjust the brightness of the official touchscreen display? I couldn't find a definite answer. I'm running the latest release of Raspbian Jessie.

21

The driver for the screen provides an interface through /sys/. To turn the screen on you can use the command:

echo 0 > /sys/class/backlight/rpi_backlight/bl_power

and to turn it off:

echo 1 > /sys/class/backlight/rpi_backlight/bl_power

the brightness can be adjusted using:

echo n > /sys/class/backlight/rpi_backlight/brightness

where n is some value between 0 and 255.

7

I've made a Python package for this: github.com/linusg/rpi-backlight. Now you don't need to implement this yourself anymore.

Example

(GIF is outdated because API was changed quite a bit in v2, sorry... Below example is correct 🙂)

Works basically like the above, example:

>>> from rpi_backlight import Backlight
>>>
>>> backlight = Backlight()
>>> backlight.brightness
100
>>> backlight.brightness = 50
>>> backlight.brightness
50
>>>
>>> with backlight.fade(duration=1):
...     backlight.brightness = 0
...
>>> backlight.fade_duration = 0.5
>>> # subsequent `backlight.brightness = x` will fade 500ms
>>>
>>> backlight.power
True
>>> backlight.power = False
>>> backlight.power
False
>>>

It has a GUI, a CLI and a simple Python API :)

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