Backlight Switcher for KDE Plasma 5

This little system tray application changes the backlight color of MSI keyboards depending on the current vitual desktop.

You need a Steelseries keyboard to use this tool. Output of lsusb on my machine:

Bus 002 Device 003: ID 1770:ff00
[...]

Building and installing

The application is built and installed in much the same way as any other KDE application. Assuming that you have Qt 5, KDE Frameworks 5 and the Plasma desktop installed, go to a suitable build location (e.g. your home directory) and do:

 git clone https://github.com/ofenrohr/backlight-switch.git
 cd backlight-switch
 mkdir build
 cd build
 cmake ..
 make
 sudo make install

Building requires CMake and also KDE Frameworks development headers and libraries. Depending on your distro, you may need to install additional packages for these. If you are running Kubuntu then see the README.kubuntu file for a list of packages required.

make install will add a udev rule to /etc/udev/rules.d that allows access to the backlight device without root privileges. You might need to reboot or execute the following commands to make it work without root:

sudo udevadm control --reload-rules
sudo udevadm trigger

Running and configuration

After the files are installed, start the switcher either from whichever desktop launcher you use (it will appear in the "Utilities" category), or by typing the command 'backlight-switch' in a terminal or KRunner (summoned by typing Alt-F2). The "desktop" icon will appear in the system tray.

If this is the first time that the application has been run the the configuration dialogue will appear automatically. Otherwise, click the right mouse button over the system tray icon and select the "Configure..." option from the menu. Turn on the "Enable Switching" check box if necessary.

Each currently configured virtual desktop will be listed there. To select the backlight color for a desktop, double click the entry or select it and click the "Set Color" button. From the color picker dialogue that appears, choose a color. Repeat the same for each virtual desktop.

Switching can be enabled or disabled using the "Enable Switching" option on the system tray popup menu.

Problems?

If you are able to build and install the application, but it will not run or it is not able to change the keyboard backlight color, then try starting it from a terminal window within the Plasma desktop. Observe the debugging messages for anything about missing files or any other problems.

If neither of this resolves the problem then please raise an issue in GitHub. Do not raise a bug against KDE Plasma.

Original applications

Thanks to Jonathan Marten for creating the wallpaperswitch application that this application is built upon.

Thanks to Steve Lacy for msi-keyboard.