Rotatable knob interface

A sensing system, comprising:

• an input device comprising a display panel, processing circuitry, and a plurality of electrodes and a rotatable electronic device configured to be attached to the display panel, the rotatable electronic device comprising:
• a stationary base, comprising:
• a bottom surface including a first set of coupling electrodes configured to be aligned with, and receive a reference signal from, a first set of electrodes of the input device, and second and third sets of coupling electrodes respectively configured to be aligned with, and receive resulting signals from, corresponding second and third sets of electrodes of the input device;
• and
• a top surface including a top peripheral portion including first, second and third regions respectively connected to the first, second and third sets of coupling electrodes;
• and
• a rotary wheel provided above and configured to rotate relative to the stationary base, the rotary wheel including a bottom surface including a bottom peripheral portion provided with alternating conductive and non-conductive regions and configured to align with the top peripheral portion of the stationary base,
• wherein the resulting signals received at each of the second and third sets of coupling electrodes are modified by the relative positions of the stationary base and the rotary wheel.

A method of processing signals from an input device having a rotatable interface, the rotatable interface including a first set of coupling electrodes aligned with and coupled to a first set of electrodes of the input device, and second and third sets of coupling electrodes respectively coupled with corresponding second and third sets of electrodes of the input device, the rotatable interface attached to a display screen of the input device, the method comprising:

• providing a reference signal to the first set of electrodes of the input device;
• receiving a resulting signal on each of the second and third sets of electrodes of the input device, the respective resulting signals modified by the rotatable interface;
• and
• determining a rotational position of the rotatable interface based, at least in part, on the two resulting signals.