How do I set up brightness control to work?

[andrejtuesday]

It is not probably working because I am on an external monitor? I am sure it is possible to fix but I do not really know how.

[Axenide]

Hi there! It depends — does your external monitor support software-controlled brightness? Ax-Shell uses brightnessctl. If you see the brightness slider, then it's supported. If you have multiple monitors, I’m not sure how it will behave. On my desktop, I only have one monitor and it doesn’t support software brightness control, so the slider doesn’t appear. But on my laptop, it does — and it works.

[andrejtuesday]

The slider appeares on my monitor but when I lower it, change it or whatever nothing happends. I also double checked and I have brightnessctl installed.

[Axenide]

Try these commands in your terminal and tell me if something happens.
What does this output?

brightnessctl --list

And this?

brightnessctl get

This should set the brightness to 50%:

brightnessctl set 50%

Increase brightness:

brightnessctl set +10%

Decrease:

brightnessctl set 10%-

Control a specific device (you get the names with the first command):

brightnessctl -d device_name set 70%

[andrejtuesday]

brightnessctl --list
Available devices:
Device 'intel_backlight' of class 'backlight':
Current brightness: 120000 (100%)
Max brightness: 120000

Device 'asus_screenpad' of class 'backlight':
Current brightness: 40 (17%)
Max brightness: 235

Device 'input4::capslock' of class 'leds':
Current brightness: 0 (0%)
Max brightness: 1

Device 'phy0-led' of class 'leds':
Current brightness: 0 (0%)
Max brightness: 1

Device 'input4::scrolllock' of class 'leds':
Current brightness: 0 (0%)
Max brightness: 1

Device 'input4::numlock' of class 'leds':
Current brightness: 1 (100%)
Max brightness: 1

Device 'asus::kbd_backlight' of class 'leds':
Current brightness: 0 (0%)
Max brightness: 3

Device 'input17::numlock' of class 'leds':
Current brightness: 1 (100%)
Max brightness: 1

Device 'input17::capslock' of class 'leds':
Current brightness: 0 (0%)
Max brightness: 1

Device 'input17::scrolllock' of class 'leds':
Current brightness: 0 (0%)
Max brightness: 1

~

brightnessctl get
120000

~

brightnessctl set 50%
Updated device 'intel_backlight':
Device 'intel_backlight' of class 'backlight':
Current brightness: 60000 (50%)
Max brightness: 120000

Lowering the brightness does nothing.

I also tried lowering the brightness with the monitor buttons manually and afterwards ran brightnessctl --list and nothing changed.

Also in the list I cannot find or associate anything with my monitor's name so probably it is not possible?

[Axenide]

Are you on a laptop and have an external monitor connected to it?
If your monitor isn't listed, then it probably doesn't support software brightness controls.
Did you test the brightness change with the device name? Just curious.
Still, you have backlight devices. That might be the reason you see the brightness slider.

[andrejtuesday]

Yes, exactly.

Also yes, I tried changing it with the name.

So it probably does not support it. Ok. Thanks for help. :)