Patent ID: 8717331

Claim:
A method comprising: measuring a first capacitance on a selected one or more of a plurality of sensor elements of a touch-sensing device during a standard scan; while measuring the first capacitance on the selected one or more of the plurality of sensor elements, coupling a reference voltage to non-selected ones of the plurality of sensor elements during the standard scan; determining whether a touch is detected in view of the first capacitance measured during the standard scan; in response to the touch not being detected in the standard scan, performing a subsequent standard scan; and in response to the touch detected in the standard scan, performing a waterproof scan to test for a presence of water on the touch-sensing device, the waterproof scan comprising: measuring a second capacitance on the selected one or more of the plurality of sensor elements during the waterproof scan; while measuring the second capacitance on the selected one or more of the plurality of sensor elements, applying a shield signal to the non-selected ones of the plurality of sensor elements during the waterproof scan; and outputting results of the standard scan when the touch is detected in view of the first capacitance measured during the standard scan and no water is detected in view of the second capacitance measured during the waterproof scan.