When interfacing a Joystick, Modwheel or Pitchbender it is sometimes found that the voltage range on the potentiometer output is well inside the range of the Core ADC input.   This can often be overcome with digital calibration in the firmware (e.g MIDIbox KB) in some cases there is extreme loss of resolution.   Presented here is a circuit to overcome this to give the ADC the full range (in this case 0..3.3V) even though the range of the potentiometer is well inside this.