US Patent 10969131 Sensor with halo light system

A thermostat for a building includes a halo light emitting diode (LED) system including one or more LEDs configured to emit light and a halo diffuser structured around at least a portion of an outer edge of the thermostat. The halo diffuser is configured to diffuse the emitted light of the one or more LEDs around at least the portion of the outer edge of the thermostat. The thermostat includes a processing circuit configured to receive one or more data streams, determine whether the one or more data streams indicate a building emergency condition, and operate the one or more LEDs of the halo LED system to indicate the building emergency condition to a user.