A touch sensor input device includes a first and second array of electrodes, the electrodes in the first array being orthogonal to the electrodes in the second array. A capacitor sensing arrangement senses an electrode capacitance signal which varies in the presence of a touch input. The capacitance signals for groups of electrodes in each array are combined in order to derive respective individual sense signals. This arrangement has electrodes with a finer resolution than the sensing resolution, and this gives improved ability to sense accurately the position of the touch input.