System and method for obtaining user input with magnetic sensing using a track ball

A system, comprising:

• a human interface device, comprising:
• a button;
• a scroll control;
• a pair of magnets mechanically coupled to the scroll control to encode movement of the scroll control in a magnetic field distribution emanating from the pair of magnets;
• a first mechanical linkage that couples the pair of magnets to the scroll control to facilitate a rotation of at least one of the pair of magnets in response to a force applied to the scroll control;
• and
• a second mechanical linkage that couples the pair of magnets to the button to facilitate a linear movement of at least one of the pair of magnets in response to a force applied to the button;
• and
• a sensing system adapted to sense the magnetic field distribution,
• wherein the second mechanical linkage comprises a retention element coupled to at least one shaft of a pair of shafts of the first mechanical linkage, the retention element being adapted to:
• enable the at least one shaft to translate along an axis of the at least one shaft, and enable the at least one shaft to return to a default position.