Adafruit forum regular, Stephanie, has another amazing project to share with us. She ripped most of the guts out of a toy Star Trek wall communicator and turned the enclosure into a custom home thermostat, the Thermostat Three.
The red circle ‘red alert light’ is wired to the XBee’s RSSI so when the XBee receives a wireless command, the red light comes on for a few seconds.
The white gridded rectangle is the DHT22 sensor (temperature and humidity). I felt it would ‘blend in’ enough that it should be mounted right up front for all to see. The little black hole to the right of the DHT22 is for the light sensor.
Why is there a light sensor? Why not? Also: because I had an extra one laying around.
The screen display is mostly self-evident. Time, day, date. Heat/Cool. Run/Hold/Override. Target temp (small) and actual temp (large). Fan status (on/auto) and humidity.