The present disclosure is of a sensing mechanism for sensing rotation movement around a rotation axis, including: a magnet; and a magnetic sensor configured to detect a magnetic flux of the magnet and to determine a relative shift between the magnet and the magnetic sensor based on change in the detected magnetic flux, wherein the magnet is shaped such that a cross section of the magnet has a width that increases from a point substantially at a center of the magnet towards each end of the magnet, thereby increasing a range of detectable change in the magnetic flux and increasing a corresponding detectable range of the relative shift between the magnet and the magnetic sensor.