In certain embodiments, an apparatus includes a display stack and a controller. The display stack includes a display and a ground layer for generating an image for the display. 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, respectively, of a first column of the plurality of columns of the ground layer such that a sum of the respective voltages of the first plurality of nodes of the first column is substantially zero. The controller also measures, to determine whether a touch event occurred, respective values at a second plurality of nodes of a second column of the plurality of columns. The respective values at the second plurality of nodes indicate an amount of charge transferred from the first plurality of nodes to the second plurality of nodes.