Patent ID: 8212159

Claim:
A machine-implemented method comprising: using a processing unit to identify a maximum x-axis charge time from a plurality of x-axis charge times, the maximum x-axis charge time corresponding to a maximum x-axis sensor location; identifying a first adjacent x-axis charge time and a second adjacent x-axis charge time, the first adjacent x-axis charge time corresponding to a first adjacent x-axis sensor location adjacent to the maximum x-axis sensor location and the second adjacent x-axis charge time corresponding to a second adjacent x-axis sensor location adjacent to the maximum x-axis sensor location; computing a first adjacent x-axis charge time ratio using the first adjacent x-axis charge time and computing a second adjacent x-axis charge time ratio using the second adjacent x-axis charge time; determining that the first adjacent x-axis charge time ratio is larger than the second adjacent x-axis charge time ratio; computing an x-axis position based upon the maximum x-axis charge time sensor location and the first adjacent x-axis charge time ratio; using the processing unit to identify a maximum y-axis charge time from a plurality of y-axis charge times, the maximum y-axis charge time corresponding to a maximum y-axis sensor location; identifying adjacent y-axis charge times, wherein the adjacent y-axis charge times correspond to adjacent y-axis sensor locations that are adjacent to the maximum y-axis sensor location; computing an adjacent y-axis charge time ratio based upon one of the adjacent y-axis charge times and computing a y-axis position based upon the maximum y-axis charge time sensor location and the adjacent y-axis charge time ratio; and mapping the x-axis position and the y-axis position to a contact location for a two-dimensional grid.