All wires of the closed loop motor are soldered and the LED dice is now in a 3D printed case. A first quick test run confirmed that it all works as intended:

Next thing to be done on the hardware side is to screw all components on a base plate and of course add the Raspberry Pi to give the world access to this new setup.

3 GPIOs on the Arduino UNO are still available, so more peripherals will be added.