Patent attributes
An apparatus includes a display stack and a controller. The display stack includes a display and a ground layer. The ground layer includes a plurality of columns. Each column of the plurality of columns includes a plurality of nodes. The controller provides voltages to a first plurality of nodes of a first column of the plurality of columns of the ground layer such that a sum of the voltages of the first plurality of nodes of the first column is less than or equal to two millivolts. The controller also measures values at a second plurality of nodes of a second column of the plurality of columns. The values at the second plurality of nodes indicates an amount of charge transferred from the first plurality of nodes to the second plurality of nodes.
