– Installation – Configuration  Troubleshooting – Download Source

A help system for laptops that have problems with adjusting screen backlight. These script aims to simplify the usage of FN buttons when using nvidiabl patch for nVidia drivers. oBacklight derived from the need of some scripts to adjust backlight on my Sony Vaio laptop with the function buttons as normal instead of writing a command in console every time. This script is built upon nvidiabl that can be found here: nvidiabl The script has been tested on openSUSE 11.2, 11.3 & 11.4 and Ubuntu 11.10 but should work on any distribution, it has been developed/tested with a Sony Vaio VPCCW1S1E Laptop but are not limited to only that brand & model.


The steps described here has been tested on openSUSE, but should work on other distributions. some knowledge about using terminal is required when following these steps.

  1. Download latest version and put in a folder of choice, this is just a temporary folder.
  2. Unpack script into same folder where you downloaded it.
  3. Open a terminal windows and log in as root.
  4. Change directory to where the script is unpacked.
  5. Copy script to /etc/init.d/.
  6. Change directory to /etc/init.d/.
  7. Make script executable and owned by root. # chmod +x oBacklight # chown root:root oBacklight
  8. Run the following command to activate the script. # update-rc.d oBacklight defaults

Script is installed and will be active on next reboot. If default settings in the script do not work see Configuration on how to change the settings.

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The script has 4 predefined brightness modes and 3 ACPI modes, these have different starting point and can be changed in the script. Edit BMT and ACPIS variables in the script to choose one of the  predefined settings.

BMT=”1” # Set Brightness Mode Types. Available types: 1, 2, 3, 4

ACPIS=”1” # Set correct System ACPI codes. Available settings: 1, 2, 3

 If you somehow need to define your own, set BMT and ACPIS to 1 and then edit values of BBL, DIDMBV, ACBU, ACBD & ACOB variables as shown below to experiment with what works for you.

# Mode 1 (Default) if [ “$BMT” == “1” ] then BBL=”2” # Default brightness level when on battery. DID=”1” # The amount of steps to increase/decrease with on backlight changes. MBV=”7” # Max brightness value possible on your system. fi

# ACPIS 1(Default) if [ “$ACPIS” == “1” ] then ACBU=”00000001 00000011” # ACPI brightness up event ACBD=”00000001 00000010” # ACPI brightness down event ACOB=”00000081 00000000” # ACPI brightness on battery event fi

When it comes to the ACPIS settings these are ACPI key events that are sent when pushing the FN  brightness up/down buttons and when the computer changes between battery/AC power, to find out which is correct for your system you can run a command in terminal called acpi_listen, this command listens on all ACPI events and prints out what their ACPI code is.

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If none of the modes in the script works you can experiment with them so they fit your system, if  you do set your own and you find settings that works for your setup, be sure to send us your working configuration and it might get added to the script as a predefined setting. If above doesn’t work at all contact us through our contact page with a detailed description abut your system and what you tested and we will try to aid you as much as we can.

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Download latest version here.

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Old versions and development status are available through the repository here: SVN

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