kuru
Who the heck is Stephan Kramer?
Found a battery-driven 6V LED strip with PIR sensor at a local shop. Put the motion sensor where it makes sense and cut off the length I needed for the keyboard stand. Compared to the Chinese LED strip I found this only has a third of the LEDs per meter, comes without a diffusor and still costs twice as much, meh. Soldered it to a cut-up old USB cable connected to the screen. Final positioning TBD and it needs a switch, maybe even a dimmer, definitely a diffusor.

