Arch Linux

twarkie

Member

Registered: 2007-09-16

Posts: 24

Screen brightness

I installed Archlinux on my HP NX7300 last week and I'm very happy with everything...except the screen brithness. Every time I boot and X starts (gdm -> gnome) the screen is very bright. It's actually brighter than max in windows.

If I use the brightness controls on the keyboard (Fn+f9/f10) to adjust the brighness, it only stays that way for a minute or so, then it jumps back to max brighness. This also happens if I start a game or a movie in vlc. This is extremely frustrating when on battery. How can I fix this?

andrewd18

Member

From: Wisconsin, USA

Registered: 2007-08-02

Posts: 34

Re: Screen brightness

Poke around in /proc/acpi/video/ and look for the brightness file inside a folder named "LCD". Look inside for the options; then run "echo 33 /proc/acpi/video/blah/blah/LCD/brightness", replacing 33 with a brightness percentage you'd like to use, and the path with the appropriate path.

If it changes and stays changed, you can use something like laptop-mode-tools to automatically set it for you. Just tell laptop-mode-tools to always remain on, and have it always set the brightness to your preferred level.

~~ Andrew D.

HydroDiOxide

Member

Registered: 2007-10-06

Posts: 99

Re: Screen brightness

I was wondering about this. I have the same problem. I can set the max brightness in gnome-power-manager (say 60% as a default), which works great. However, when I change the brightness with the FN+F5 or F6 (down or up), my brightness gets reset after a minute to the brightness which I set in gnome-power-manager.

Also, the brightness I can set with the FN keys is in much larger increments than in gnome-power-manager. Is there a way to adjust this?

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"Overspecialize and you breed in weakness..." Major Motoko Kusanagi

thunderogg

Member

From: Rio de Janeiro

Registered: 2008-07-13

Posts: 172

Re: Screen brightness

Why don't you try the Gnome Brightness Applet? Right click on the panel, and click "Add to Panel" then choose it from the list. It works fine on my HP Pavilion dv 6000.

ibendiben

Member

Registered: 2007-10-10

Posts: 519

Re: Screen brightness

I use xbacklight for this. Works great.
Here's the man page: http://linux.die.net/man/1/xbacklight
Brightness value's are set to 100 during boot, you'll have to put a line in /etc/rc.local or put a script in the autostart folder of your desktop environment (.kde/Autostart/), defining the correct brightness value. I use "xbacklight -set 40".
You can use xbindkeys to bind your brightness keys to xbacklight commands and let them increase or decrease the value by a specified amount.
Here's man xbindkeys too: http://linux.die.net/man/1/xbindkeys

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