It can not give an intensity . For this setup , an analog joystick can be `` self calibrated '' just by leaving the joystick in the middle position and taking a measurement , and then using some arbitrary or adaptive threshold to detect movement and excursion from the middle position . In general , if only a purely directional input with no precise intensity information is required , an analog joystick can be `` self calibrated '' just by leaving the joystick in the middle position and taking a measurement , and then using some arbitrary or adaptive threshold to detect movement and excursion from the middle position .