How could I dim the external display brightness in Plasma 5?

I'm using Plasma 5 for GNU/Linux in a desktop PC box. I would need a way to dim display brightness, but I have absolutely no idea where to start looking for it. Whatever you come up with, CLI solutions are welcome, but it's not necessary for me to have a CLI solution.

174140

Posted 2017-11-28T17:25:12.573

Reputation: 859

Answers

Not tried with external monitor, but it seems you can:

List your displays:

xrandr -q | grep -w connected

HDMI1 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 376mm x 301mm

Using the name(s) listed, set the brightness:
```
xrandr --output HDMI1  --brightness 1.0
```

(from here)

xenoid

Posted 2017-11-28T17:25:12.573

Reputation: 7 552

It is working for the VGA-0 display (yay!) but not for the DVI-D-0 and HDMI-0 displays. In any case, thank you very much! – 174140 – 2017-11-30T12:14:41.937

It works with DisplayPort-0 – TitanFighter – 2020-01-19T14:57:14.130

In the KDE workspace this is easily done via the "Battery" widget/plasmoid (this widget auto-hides when the battery is filled up, so you may have to search it a bit):

xenoid

Posted 2017-11-28T17:25:12.573

Reputation: 7 552

My understanding is that this brightness control only works with laptop screens (it may not even appear on a desktop system). That's probably why it's bundled with battery power management. – fixer1234 – 2017-11-30T04:32:19.320

Can you force this if there is no battery? If not, then I can't accept the answer, because this was for a desktop box. – 174140 – 2019-07-31T08:51:03.640