Low pin count solution using capacitance sensing matrix for keyboard architecture

An apparatus comprising:

• a sensing device comprising a plurality of sensor elements to detect a conductive object, wherein a plurality of keyboard keys are assigned to correspond to pre-defined areas of the sensing device, wherein the pre-defined areas are disposed adjacent to one another without any space between, wherein at least one of the plurality of sensor elements corresponds to multiple pre-defined areas, and a number of the plurality of keyboard keys is greater than a number of the sensor elements, and wherein each of the pre-defined areas corresponds to a separate one of the plurality of keyboard keys;
• and
• a processing device coupled to the sensing device, and comprising a look-up table storing positional data of the pre-defined areas, wherein the processing device is operable to determine a position of the conductive object on the sensing device based on measurements representing capacitance on the plurality of sensor elements, to select a keyboard key of the plurality of keyboard keys by comparing the position of the conductive object to the positional data of the pre-defined area of the sensing device corresponding to the keyboard key, and output keyboard data corresponding to the selected keyboard key to a host processor external to the processing device.