A thermostat may include a user interface having a first operating mode and a second operating mode, and a first proximity sensor configured to detect a user presence within a first range, the first proximity sensor comprising a plurality of channels comprising a left channel and a right channel, the right channel producing a response when a user presence is detected to the right of the thermostat, and the left channel producing a response when a user presence is detected to the left of the thermostat. A processing system may be programmed to receive an indication of a user presence within the first range from the first proximity sensor, the indication of the user presence being associated with responses from a plurality of the channels of the first proximity detector, and determine a motion signature based on the responses from the plurality of the channels of the first proximity detector. A processing system may also be programmed to process the determined motion signature to determine the presence of a condition warranting user interface entry into the second mode from the first mode, responsive to determining the presence of the conditions, cause the user interface to transition from the first operating mode to the second operating mode based on the determined motion signature.