US Patent 11221709 Electronic writing apparatus with ring-back and other functionalities

A circuit includes a function module, a processing module, and a transceive circuit. The function module is operably coupled to detect stimulus of an electronic writing apparatus and generate functional data based on the stimulus. The processing module is operable to generate an outbound data signal from the functional data. The transceive circuit is coupled to a conductor of the electronic writing apparatus and includes a reference circuit operably coupled to, generate an identifier signal having a unique waveform characteristic that is an identifier for an aspect of the electronic writing apparatus, and combine the outbound data signal with the identifier signal to produce a transmit reference signal. The transceive circuit also includes a drive-sense circuit that is operably coupled to regulate the transmit reference signal on the conductor and generate an error correction signal based on the transmit reference signal and an inbound signal received via the conductor.