Kitchen Relay & Sensor Node
Mains switching plus climate sensing on one small board behind the kitchen wall plate.
- Relay switching with the existing wall button still wired through
- BMP280 for temperature and pressure in the same enclosure
- Status LED on the faceplate
A retrofit node that fits behind an existing kitchen wall plate. The relay does the switching, and the original physical button stays wired as an input — so the light works normally if the network is down, which is non-negotiable for anything mains-connected in a room you use daily.
A BMP280 rides along on the same board for temperature and pressure, on the reasoning that if a board is already going into the wall with power available, it may as well report something. The one compromise is that a sensor sharing an enclosure with a switching relay reads a little warm — it is fine for trend data, less so for absolute accuracy.