1. An apparatus comprising: a sensor comprising a plurality of electrodes; and a computer-readable non-transitory storage medium embodying instructions; and one or more processors coupled to the media and configured to execute the instructions to: determine, based on output from the sensor, a proximity of an object to the apparatus; compare the determined proximity to a threshold proximity; select, based on the comparison, an interaction mode for processing interactions between the object and the apparatus, the interaction mode comprising one of: a first interaction mode wherein the position of an object is determined relative to a first number of the electrodes; and a second interaction mode wherein the position of the object is determined relative to a second number of the electrodes that is greater than the first number of the electrodes; and when the second interaction mode is selected, detect, based on an electromagnetic interference (EMI) signal received at the sensor, the object, wherein the EMI signal is generated at least in part by an electronic component external to the apparatus; and when the first interaction mode is selected, detect, based on a capacitive signal generated at the sensor by the object, at least a portion of the object.