Patent ID: 7609253

Claim:
A method for processing signals from a plurality of sensor electrodes in a closed loop sensor device comprising: receiving a set of signals, the set of signals comprising a signal from each of the plurality of sensor electrodes in the closed loop sensor device; determining a set of capacitance values, the set of capacitance values comprising a capacitance value for each of the plurality of sensor electrodes from the set of signals; determining positional information of an input object proximate to the closed loop sensor device using the set of capacitance values, wherein the determining positional information of an input object comprises: determining a highest capacitance value sensor electrode of the plurality of sensor electrodes using the set of capacitance values; determining a quadratic fitting from a capacitance value of the highest capacitance value sensor electrode, a capacitance value of a first one of the plurality of sensor electrodes on a first side of the highest capacitance value sensor electrode, and a capacitance value of a second one of the plurality of sensor electrodes on a second side of the highest capacitance value sensor electrode; determining a center point of the quadratic fitting; and determining positional information from the center point; and generating an output based on the positional information.