Patent attributes
A touch-sensitive device includes a capacitance-based touch sensor, drive circuitry configured to drive touch sensor electrodes with a synchronization waveform to enable an active stylus to become time synchronized with the touch-sensitive device, and receive circuitry configured to determine a position of the active stylus based on electrostatically receiving a first waveform from the active stylus. Depending on when the touch-sensitive device receives the first waveform from the active stylus, the touch-sensitive device interprets the first waveform differently to determine a position of the active stylus or determine that the active stylus is hovering. In either case, the same waveform is used to communicate different information about the active stylus to the touch-sensitive device.
