For this project I wanted to use hall sensors instead of a physical switch for sending a trigger at certain angular intervals of the polarization filter. I ordered magnets with a diameter of 5mm and a length of about 8mm, which, after a bit of drilling, fit inside a lego hole (which is D=4.8mm). Now I have a magnet passing a hall sensor 12 times per rotation which feeds into an ESP32, which converts it to a single shot PWM trigger signal for the camera (exposure time = duty cycle to be set with potentiometer).