Based on a number of excellent suggestions I got in previous thread, I have decided to convert all my smart home devices over to ZigBee. I have about 50 switches and sensors on-order at the moment.
One thing I can’t seem to find is a controller for my pellet stove. My stove is installed in my workshop, and during the winter, I usually have to run out to the shop in the morning, turn the stove on, then wait for a hour or two for it to warm up.
I’m thinking that I’ll most likely need to build a controller for the stove. I had some issues with the mainboard in the stove last year, so I’m fairly familiar with how it works. There area few sensors and relays.
- An on/off sensor for the lid.
- A safety sensor for the hopper (makes sure flames aren’t feeding back into the hopper).
- A pressure sensor to detect if the door is open.
- An external temperature probe.
- An internal temperature probe.
- A relay for the igniter.
- A relay for the motor that rotates the hopper.
- A relay for the induction fan.
- A relay for the fan that blows warm air out from the stove.
- A potentiometer that switches the stove on and controls the temperature set point.
I have built a number of custom PCBs in the past, and I’m confident that I could build a replacement for the mainboard that includes a ZigBee radio. This requires a significant amount of design work for the PCB, programming for the microcontroller, etc. I’m also just now learning about how the ZigBee protocol works, so there would be a fair amount of research involved.
My other idea was to build a PCB that essentially acts as a programmable potentiometer, replace the pellet stove’s pot with this PCB, and leave the mainboard as-is.
Has anyone here tried integrating a pellet stove into your home automation? How did you do it?
Would it help, to add a switch in the potentiometer path? When you disconnect ground from the potentiometer, will the stove shutdown gracefully?
That could be a simple way…
I think that’s the solution I’m going to go for. While my idea of building a custom mainboard does sound like a lot of fun, my main concern is with the code. The factory mainboard has set points where it turns the hopper, disables/enables the blower, etc. I could probably get it close in my own code, but I’m sure there are edge cases the factory engineers found that I would miss. I don’t much enjoy the idea of going out to my shop and finding it full of smoke or my stove jammed full of pellets, or worse the whole thing on fire.