An electronic device is disclosed. In some examples, the electronic device comprises a rotatable mechanical input mechanism. In some examples, the electronic device comprises sense electrode positioned proximate to the mechanical input mechanism. In some examples, the electronic device comprises a capacitive sense circuit comprising drive circuity operatively coupled to the mechanical input mechanism and configured for driving a drive signal onto the mechanical input mechanism. In some examples, the electronic device comprises a capacitive sense circuit comprising sense circuitry operatively coupled to the sense electrode and configured to measure an amount of coupling between the rotatable mechanical input mechanism and the sense electrode. In some examples, the electronic device comprises a housing, wherein the sense electrode is included in a gasket for connecting a display to the housing.