RE: HA Holy Grail #1: Occupancy Detection

["Andy Laurence" <andy@xxxxxxxxxxxxxxxxxx>]

From: ian.bird@xxxxxxx [mailto:ian.bird@xxxxxxx]
> I use this in the kitchen and have two observations.
> 1) Ambient light in the room should be considered and

Do they not work in the day?

> 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.

I don't have X10 to worry about.  I'm going to use a xAP NetIOM for inputs,
and the same device uses relays to turn the lights on and off.  I've not
soldered up the relay board yet though!

> 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.

When you're ready for production, I'll take a few ;-)

I'll see how I get on with a PIR, and evaluate from there.  I need to
solder up that relay board first though, otherwise the automated lighting
will never get off the ground!

Cheers,
Andy