A touch sensor apparatus includes a grid of intersecting sensor lines, a plurality of input/output (IO) pins, a plurality of diodes, a processor coupled to the IO pins. More specifically, each intersection includes a capacitor coupling together the intersecting sensor lines. Each diode is coupled to a corresponding IO pin, wherein each IO pin couples through its corresponding diode to a channel of intersection points of the sensor lines and, without the diode, each IO pin couples to a different channel of intersecting points of the sensor lines. The processor is configured to sequentially provide a transmit signal through each IO pin while detecting a response signal on the other IO pins.