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ebaauw / homebridge-rpi

Homebridge plugin for Raspberry Pi.
Apache License 2.0
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Feature request: heat detector support #49

Closed ebisu closed 4 years ago

ebisu commented 4 years ago

First of all, thank you for creating/sharing this wonderful plug-in. It transformed my 20-years-old home security system into a smart home security system. All my doors/windows are wired to HomeKit. Homebridge-rpi works like charm!

There is one sensor that I'm not able to migrate properly though. It's a mechanical heat detector. It's commonly used where smoke sensor is not a good option. Kitchen and garage are the most common application as the environment tends to damage smoke detectors.

You can find the technical details of mechanical heat detectors here. https://www.systemsensor.com/en-us/Documents/5600_Series_Manual_I56-2175.pdf

It would be awesome to allow HomeKit handeling state of connected pin just like smoke detectors.

Thank you!

ebaauw commented 4 years ago

I’m happy to create a smoke device to have it exposed to HomeKit as Smoke Sensor, but the tricky part (for me) is how the detectory connects to the Pi. I don’t think HomeKit defines heat sensors. Also, they haven’t yet cracked the history for the Eve Smoke, afaik, so (initial) support will be without history.

Do I understand correctly that it just uses a binary input GPIO signal that is active to indicate the alarm? Did you already hook it up to the Pi? Can you try and expose it as a contact device and see if Homebridge RPi detects input changes when the detector fires?

ebisu commented 4 years ago

Yes, heat sensors use a binary input GPIO signal. I've tested it as a contact device. It's normally opened (no fire). It should changed to close when detecting fire. The detection method is based on the spring action of a metal contact, held to the metal chamber by a fusible alloy. When the temperature reaches the alloy’s melting point, the metal contact will depress the diaphragm, causing the electrical contact to close the circuit. It's non-resettable, and cannot be tested unfortunately.

I agreed that exposing heat sensors as smoke devices would work. Both sensors detect the same hazard in different ways.

ebaauw commented 4 years ago

In v1.1.14.

ebisu commented 4 years ago

Verified! Closing this feature request. Thank you so much!