One of the joys of browsing secondhand shops is the possibility of finding old, perhaps restorable or hackable, electronics at low prices. Admittedly, they usually seem to be old flat-screen TVs, ...
The MT6701 is an easy to program magnetic rotary position sensor with a high-resolution 12-bit analog, PWM, UVW, ABZ. With SPI and I2C output is 14 bit. They should provide magnetic button ...