A device for detecting the position of a human finger or other object on a
touch-sensitive scrolling pad. Dual independent oscillators may be used
to generate two pulse trains at frequencies dependent upon the
capacitance of two conductors resulting from the position of the finger
on the conductors. The pulses from each oscillator may be counted over a
time interval. A ratio-metric measurement may be taken by calculating the
ratio of the two counts, and a sum may also be calculated. The ratio of
the two counts relates to finger position on the device, and their sum
relates to finger pressure upon the device.
