Patent attributes
A sensing system is provided. A processing system drives a first subset of sensor electrodes with a sensing signal and receives corresponding resulting signals. The processing system also drives a second subset of the sensor electrodes with a reference signal and a third subset of the sensor electrodes with a guard signal. A rotatable electronic device includes a first coupling electrode and a second coupling electrode. The second coupling electrode couples with and receives the reference signal from the second subset of the sensor electrodes. The rotatable electronic device also includes a conductive region that rotates relative to the first coupling electrode and the second coupling electrode. The resulting signals are affected based on the position of the conductive region relative to the first coupling electrode when the first coupling electrode is coupled with the first subset of the sensor electrodes.