Re: HA Holy Grail #1: Occupancy Detection

[ian.bird@xxxxxxxxxxxxxx]

Hi Andy

I use this in the kitchen and have two observations.
1) Ambient light in the room should be considered and
2) As Paul mentions PIR lag and subsequent X-10 transmission delays (if
you use X-10 that is) make the lights slow to _very_ slow at times.

As for my system - I have just had some ultrasonic range sensors arrive
from the States and I hope to use these to cover the kitchen area and then
with some wizardry I can note the 'normal' distance returned and thereby
know when it varies. If it varies it must mean something is in there,
hopefully a person. With some programming this could become intelligent
too and adapt. This might be relevant in the winter for example when we
hang washing from the ceiling dryer (there is an AGA in the kitchen so
everything dries overnight). If all this works I will retire the PIR
gladly as no movement switching off and long off times to compensate are a
pain. This is probably a winter project though.

Thanks

Ian






"Andy Laurence" <andy@xxxxxxx>
Sent by: ukha_d@xxxxxxx
22/08/2006 09:49
Please respond to ukha_d


To:     <ukha_d@xxxxxxx>
cc:     (bcc: Ian Bird/CV/Novartis)
Subject:        [ukha_d] HA Holy Grail #1: Occupancy Detection


I've finally puched down all the CAT5 in Node0, so it's time to think
about lighting.  I've got the switches and lighting controllers sorted,
but what I'd really like is automgic lights.  This leads me in pursuit of
the holy grail.  Occupancy detection.  Has anyone got a reasonably
reliable method of occupancy detection?  I'm thinking a sensitive PIR,
which triggers a timer and turns the light on.  When the timer reaches
zero the light goes off.  Whenever the PIR is triggered, it resets the
timer.  I suspect I can do this with xAP Floorplan, although I've not
checked yet.  Has anyone implemented this?  If so, any recommendations for
PIRs?

Cheers,
Andy







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