laptop - Backlight brightness on Mint 16 (GeForce 330M)

07
2014-07
  • qj0n

    I have Dell Vostro 3700 with GeForce 330M and use the nouveau driver. I have Mint 16 with Cinamon. I want to be able to change backlight with keyboard shortcuts. I did some changes to kernel parameters, so now I can change brightness from command line, by echoing number to /sys/class/backlight/nv_backlight/brightness. In the meantime, I have another directory /sys/class/backlight/dell_backlight, but echoing there doesn't change anything

    Keyboard shortcuts are also captured. Cinamon shows brightness slider, but using it changes content of dell_backlight/brightness, not nv_backlight. How can I enable changing brightness (in nv_backlight dir) from desktop environment?

    • Answers
  • qj0n

    I made a workaroud: Create a script in /usr/bin/update-backlight

    #! /bin/bash
cp /sys/class/backlight/dell_backlight/brightness /sys/class/backlight/nv_backlight/brightness

    And add an udev rules /etc/udev/rules.d/80-backlight.rules

    SUBSYSTEM=="backlight", ACTION=="change", DEVPATH=="/devices/platform/dell-laptop/backlight/dell_backlight", RUN+="/usr/bin/update-backlight"

    This copies value one value to another every time I change backlight brightness.


    • Related Question

    display - Tool to adjust monitor's backlight brightness in Windows
  • GetFree

    Do you know of any tool for Windows that let me adjust the backlight brightness of a monitor?


    • Related Answers
  • Bartek Banachewicz

    The solution I am using right now

    I found enable DDC/CI option in my displays' settings. The ScreenBright program was able to modify it, although I think it's GUI is quite terrible and easy to break you custom settings. My screens also flicker a lot when changing brightness. Nevertheless, it has a commandline interface, which is much better. Especially when you create your own GUI (which is around 5 minutes in C#) or use plain Windows shortcuts.

    Old setup

    As a side note to the Dell brightness change - I can confirm that it also did work for me. My setup was:

    • Dell Latitude laptop (5520 I believe)
    • Dell Docking station (the extended version)
    • 2xDell u2412m screens, connected via DVI

    The laptop itself had a built-in GPU (Intel HD2500). In its software there was a tab called "monitor settings", iirc. It did indeed communicate with the displays and somehow change their built-in brightness settings. I weren't able to do much more (change profiles, for example), and it took quite a while to "initialize". There was also a 2-3 second delay between the setting of the brightness and actual change. I guess it was mostly due to the screens, which changed brightness gradually.

    I've updated my PC to the regular workstation, and unfortunately I wasn't able to find similar setting in the NVidia control panel.

    EDIT: It seems that my previous setup used DDC.

  • oKtosiTe

    The application Display Tuner can control the brightness for many different LCD/CRT monitors.
    However, if backlight is a separate setting on your monitor, you might be out of luck.

  • nhinkle

    Are you talking about an external monitor or a laptop's built-in display? An external monitor's brightness is almost always controlled externally by the monitor, there just isn't any way to pass brightness settings information over any of the usual display connectors (VGA, DVI, HDMI, DisplayPort, etc.). A built-in display on a laptop or all-in-one however has its brightness control integrated with the system, and can be controlled from within windows by some software. The actual software to do so will depend on the manufacturer. Windows 7 can do it automatically from the Windows Mobility Center (press Win+X), but in Windows XP you will need the manufactuer's drivers.

  • Journeyman Geek
    • If you use an Nvidia Graphics Driver (Resource from here )

    1. Right click on desktop and select NVIDIA Control Panel

    2. Click on “Adjust desktop color settings” at the left hand side navigation bar.

    alt text

    3) Select NVIDIA settings and you can now move the slider for Brightness and Contrast.

    Have a look here

    http://www.istartedsomething.com/20090829/windows-7-application-controls-backlight-ordinary-webcam/

  • Indrek

    Use Desktop Lighter. It's freeware. After installation you can simply use shortcut keys to increase or decrease brightness. Your monitor's brightness control is at your fingertips. Shortcut keys can be customized. It's a small tool but very useful.