US 11,928,271 B1
Capacitive knob sensing system and method to detect initial states
Kelvin Fong, Milpitas, CA (US); Tomohiro Hirakawa, Chiba (JP); and Yan-Ju Du, Xiamen (CN)
Assigned to Synaptics Incorporated, San Jose, CA (US)
Filed by Synaptics Incorporated, San Jose, CA (US)
Filed on Aug. 24, 2022, as Appl. No. 17/821,866.
Int. Cl. G06F 3/0362 (2013.01); B60K 37/06 (2006.01); G06F 3/044 (2006.01)
CPC G06F 3/0362 (2013.01) [B60K 37/06 (2013.01); G06F 3/0446 (2019.05); B60K 2370/126 (2019.05)] 19 Claims
OG exemplary drawing
 
1. A method for determining a rotational direction of a knob interface, comprising:
obtaining, by a processing system and using a set of rotation electrodes that interact with the knob interface, first resulting signals and second resulting signals, wherein obtaining the first resulting signals and the second resulting signals comprises:
obtaining, from the set of rotation electrodes, the first resulting signals, wherein the first resulting signals are obtained without providing a reference signal to a set of reference signal electrodes that interact with the knob interface; and
obtaining, from the set of rotation electrodes, the second resulting signals, wherein the second resulting signals are obtained in response to providing the reference signal to the set of reference signal electrodes;
determining, by the processing system, an initial state of the knob interface using the first resulting signals and the second resulting signals;
obtaining, by the processing system and using the set of rotation electrodes, third resulting signals indicating a first rotational state of the knob interface, based at least in part on the knob interface being rotated from the initial state to the first rotational state;
determining, by the processing system, the rotational direction of the knob interface using the first resulting signals, the second resulting signals, and the third resulting signals; and
adjusting, by the processing system, a setting using the determined rotational direction.