A thermostat for controlling an HVAC system in an enclosure may include a passive infrared sensor, an active infrared sensor, and an electronic display having a first mode and a second mode. The thermostat may also include one or more processors programmed to change a setpoint temperature of the thermostat to an energy-saving temperature upon detection of a non-occupancy condition for the enclosure. The processor(s) may detect the non-occupancy condition based at least in part on readings received from the passive infrared sensor. The processor(s) may also be programmed to change the electronic display from the first mode to the second mode upon detection of a person approaching the thermostat. The processor(s) may detect a person approaching the thermostat based at least in part on readings received from the active infrared sensor.

A thermostat for controlling an HVAC system in an enclosure may include a passive infrared sensor, an active infrared sensor, and an electronic display having a first mode and a second mode. The thermostat may also include one or more processors programmed to change a setpoint temperature of the thermostat to an energy-saving temperature upon detection of a non-occupancy condition for the enclosure. The processor(s) may detect the non-occupancy condition based at least in part on readings received from the passive infrared sensor. The processor(s) may also be programmed to change the electronic display from the first mode to the second mode upon detection of a person approaching the thermostat. The processor(s) may detect a person approaching the thermostat based at least in part on readings received from the active infrared sensor.

A thermostat user interface for a network-connected thermostat is described. The thermostat includes a frustum-shaped shell body having a circular cross-section and a sidewall extending between first and second ends, the second end being user-facing when the thermostat is wall-mounted; a circular rotatable ring being user rotatable for adjusting a setting of the thermostat; and a circular cover including a clear circular center portion surrounded by a painted outer portion. The clear circular center portion permits a corresponding circular portion of a non-circular dot-matrix color display element to be visible through the circular cover and the painted outer portion masks a remaining portion of the non-circular dot-matrix color display element so as to create a circular graphical user interface.

An electronic thermostat is described that includes a head unit, a rotatable ring, a backplate, an electronic display that is viewable by a user in front of the thermostat, a printed circuit board, and a daughter circuit. The daughter circuit is coupled to the printed circuit board, and senses motion of the rotatable ring and includes a first temperature sensor. A second temperature sensor separated from the first temperature sensor, are both used to calculate ambient temperature. The first temperature sensor is positioned at least partially within a cavity formed between a front surface of the head unit and the printed circuit board.