I am remachining the shifter drum in a sequential gearbox to improve racing. I want to be able to identify current selected gear and plan to do so by replacing the 'neutral light sensor' on the engine with a potentiometer. I will machine in 7 different protrusions on the drum to correspond with each gear. However, I only have a depth of about 10 to 12mm to play with so I will have to make 7 discrete steps of about 1.5mm each. Does anyone know of a device that will reliably give an output that I can process through a microcontroller to give an output to a LCD?