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.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.