Difference between occupancy and presence alarms

Developers
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1

Hello,

I’ve started looking into the Tuya app so that I could add a non-supported temperature sensor. One thing leading to another I’m rewriting the driver for a mm-Wave presence sensor.

There comes my question: the difference between presence / occupancy and motion alarms is quite clear.

However what difference is there between a presence alarm and an occupancy alarm ?

In my view (and this is not how the Tuya drivers for radars work so far), these devices should mostly trigger a presence (or is it occupancy ?) alarm. The “motion alarm” can then be derived from the transition from no-presence to presence (or occupancy - you get the idea…) and a cool-down period. Some devices (mine apparently) also report the “motion state” (from no motion to large motion, etc.) so I could easily have a setting saying “any motion state above “small” motion will trigger the motion alarm”, etc.

Is it just a matter of vocabulary ?

Should presence be tied to users being present (and a presence alarm goes off only if another users gets home) and occupancy alarms relate to specific rooms ?

Thanks

2

To me a occupancy sensor it is just a commercial opgrade of a motion sensor. As every knows the issue that when you visit to the toilet takes too long, you have to wave your hands to get the lights on again. And of course, a occupancy sensor solves that problem🤨.
For example Philips renamed his SML00xx motion sensors in occupancy sensors, requiring a software upgrade of the app “hue without the bridge”, whilst the technology used is still the same.
You cannot be present in a room without going into the room. So you have to look at the technology used. The (only?) way to detect occupancy without motion, is to “take a picture of the room” and compare this picture with a picture of the empty room.

3

Sure, I agree with that.

But what’s the difference between occupancy and presence ?

Edit: HomeKit only considers occupancy for all three concepts (motion, presence and occupancy).

4

Matter of language: When you are present in a room, the room is occupied.