So I am making an automobile temperature control system using a temp. sensor, ADC and 8052 microcontroller. I want to give the user of the system the option to select their desired temperature inside the car. for that I am thinking about using a rheostat with a ADC. The varying voltage will let the microcontroller know when to turn the AC off. But rheostat's dial movement is smooth. I need something like a rheostat whose dial movement is not smooth but sort of jerky.... like the dials in handheld DMMs.... so I would know that at, say, position 2 I have, say, 2 volts coming. Does anyone know what kind of component would be perfect for this?