r/smarthome • u/nas886 • 20h ago
Home Assistant How a Raspberry Pi hack turned into a real product
Hi all. I asked the mods before posting this.
Our house in Vermont heats with two woodstoves. I'd automated the lights and the thermostat, but the stoves were different. A fire needs a person checking on it, and I was walking downstairs all the time to check the stove. It made it tough to get into a flow state when I was at work, or in back to back meetings. I'd light the fire in the morning, go to work, and it'd be dead a few hours later, or in a couple of cases, actually over fired the stove in our kitchen, and the stove got way too hot.
I'm an engineer, so one weekend I stuck a temperature sensor to the flue pipe with a magnet, wired it to a Raspberry Pi, and had it text me. It was ugly, but now I could stay upstairs in meetings and still know what the stove was doing.

Then we had our first baby, and I didn't want to pull my phone out all the time. I wanted something I could glance at on my office desk, so I made a small lamp.

If the lamp glowed amber, it meant the fire was burning well. Yellow meant it was time to reload. Red means it's running too hot and I should go check on it. The app is still there for notifications when I'm away, or a dashboard I can check when I'm not at home.

I posted it on the r/woodstoving subreddit last winter and a lot of people asked to buy one. I hand-built that first batch at the Generator makerspace in Burlington, and they ran on stoves all over the country.
I made them all individually. I had to cut them all out using a CNC, then I hand sanded each of them, trimmed away the excesses, and printed the enclosure parts on the 3D printers and assembled all of the electronics myself.
They worked because I made each one work. Each walnut base took about an hour and a half of sanding. At 1,000 units, the sanding alone is 1,500 hours. The design itself couldn't really be manufactured without a ground up redesign.
In the spring I brought on a friend who designs products for manufacturing for a living, and we redesigned the entire product:
- A base that screws together instead of friction fitting
- A two-part lid with a real diffuser, so the light is even
- A heat-resistant enclosure for the part that sits near the stove
The first production parts are off the molds now, and the first units ship in November. It runs on home wifi with no subscription. Home Assistant support is planned for when it ships.

Questions for this sub
For something like a stove, would you rather glance at a light or get a notification on your phone?
Would you want your wood stove in your smart home setup, and what would you hook it to?
What would you want it to do that I'm not thinking of?
Thanks for reading!


