RE: HA Holy Grail #1: Occupancy Detection

["Andy Laurence" <andy@xxxxxxxxxxxxxxxxxx>]

From: Ian Lowe [mailto:ianlowe@xxxxxxx]
> Remember as well that PIRs normally have a "pulse count"
setting to reduce
> false alarms - in most cases, the PIR can be made more sensitive by
reducing
> the pulse count from 3 to 1.

I've found a PIR at Maplin (http://www.maplin.co.uk/Module.aspx?ModuleNo=12576&criteria=PIR&doy=22m8)
that looks pretty raw.  Hopefully it'll be quite sensitive, as there's none
of the filtering you'd normally get.  I'll probably try one as it's small,
and cheap!

> I think any Occupancy system has to use a variety of techniques -
pressure
> pads, beam breaks, pirs, even CCTV with motion detection indoors
(although
> that has it's own "big brother" style concerns).

I was thinking the same thing about multiple sensors.  Pressure pads would
be good for places you tend to sit for some time without moving, such as
the sofa, and the bath.  Beam breaks will probably make the lights come on
a little quicker.  PIRs are probably a good all-rounder for when you have
regular movement in a room.  I had thought about motion detection using
CCTV, but there's probably issues with clouds varying sun into the room,
and other similar factors.  Then there's the processing power required for
10 motion sensing CCTV cameras....

Cheers,
Andy