A shared electrode pattern field effect touch sensor apparatus, comprising: a dielectric substrate; first through fourth spaced electrode patterns (82, 84, 86, 88) disposed on said substrate in a circular configuration, each of said first through fourth patterns having an inner electrode and an outer electrode, each said inner electrode including a primary portion defining a primary sense area and at least one secondary portion; a fifth electrode pattern disposed in a centre portion of said circular configuration, said fifth electrode pattern having an outer electrode and an inner electrode that includes a primary portion defining a primary sense area and four secondary portions, each of said secondary portions of said fifth pattern adjacent to one of said secondary portions of said first through fourth patterns to define four secondary sense areas; first through fifth pulse generation and detection circuits disposed on said substrate, each of said pulse generation and detection circuits electrically coupled to a corresponding one of said first through fifth patterns, said inner and outer electrodes of said first through fifth patterns arranged such that the presence of a stimulus proximate one of said primary sense areas causes the corresponding one of said first through fifth pulse generation and detection circuits to output a touch signal, and the presence of a stimulus proximate said secondary sense area causes the corresponding two of said first through fifth pulse generation and detection circuits to output a touch signal; and a controller (C') in communication with said first through fifth pulse generation and detection circuits, said controller adapted to receive said touch signals and to output control signals indicative of the presence at said controller of a touch signal output by one of the first through fifth pulse generation and detection circuits, or the two of said first through fifth pulse generation and detection circuits. a dielectric substrate; first through fourth spaced electrode patterns (82, 84, 86, 88) disposed on said substrate in a circular configuration, each of said first through fourth patterns having an inner electrode and an outer electrode, each said inner electrode including a primary portion defining a primary sense area and at least one secondary portion; a fifth electrode pattern disposed in a centre portion of said circular configuration, said fifth electrode pattern having an outer electrode and an inner electrode that includes a primary portion defining a primary sense area and four secondary portions, each of said secondary portions of said fifth pattern adjacent to one of said secondary portions of said first through fourth patterns to define four secondary sense areas; first through fifth pulse generation and detection circuits disposed on said substrate, each of said pulse generation and detection circuits electrically coupled to a corresponding one of said first through fifth patterns, said inner and outer electrodes of said first through fifth patterns arranged such that the presence of a stimulus proximate one of said primary sense areas causes the corresponding one of said first through fifth pulse generation and detection circuits to output a touch signal, and the presence of a stimulus proximate said secondary sense area causes the corresponding two of said first through fifth pulse generation and detection circuits to output a touch signal; and a controller (C') in communication with said first through fifth pulse generation and detection circuits, said controller adapted to receive said touch signals and to output control signals indicative of the presence at said controller of a touch signal output by one of the first through fifth pulse generation and detection circuits, or the two of said first through fifth pulse generation and detection circuits.