“This instructables show how to use a industrial Hall Effect joystick to make a high presision USB joystick.
There are another related instructables Tiny USB Joystick that can provide low cost solution ;>
Normal USB joystick use 2 potentiometers as sensors on X-axis and Y-axis.
There are a few limitations on potentiometer:
not sensitive enough on minor movement (minor resistance change)
physical contact in the sensor is easy worn out (short lifetime)
the worn out in partial area make the axis movement return nonlinear value (return incorrect value)
In contrast, Hall effect sensor is contactless in sensor part, so not easy worn out and give a lifelong precise value.”