JAJU657 December 2018
Adding touch gesturing to a capacitive touch wheel, slider, or button sensor enables a more flexible human-machine interface (HMI) compared to a traditional mechanical button operation in which a button is either on or off. For example, with a capacitive touch wheel, a simple finger tap anywhere on the wheel sensor can represent a button press. Multiple touch zones can be mapped on the wheel, providing the equivalent of having several discrete buttons. In addition, the wheel can detect the motion of a finger to control user inputs like a volume control or can detect a rapid swipe motion to provide some other type of control input. Of course, moving from a traditional discrete on-off button functionality to a more feature-capable wheel does require some intelligence to translate these actions and motions into the desired functionality. This intelligence is gesture detection.
The following sections describe the gestures, motion parameters, and timing diagrams for each of the supported gestures. For more detailed information about gesture software and tuning, refer to Capacitive Touch Gesture Software and Tuning.