Sensors for doors & windows & ...

[Chris Hunter <cjhunter@xxxxxxxxxxxx>]

'thinking of sensors for doors & windows ... and the limitations of
the reed-switch (just open or closed & no certainty on what it's
telling about the door, unless perhaps it's attached to the locking
mechanism in some way - which can't see how to do as a retro-fit) ...
was trying to think how else ... strain-gauge ... laser + mirror ...
all have just-as-bad limitations ... hmmm ...

'wonder if PIRs are all the same ... obviously not, but in the sense
of being designed to pick-up just movement .... are there some that
are designed to pick-up position, say, or presence not associated
with movement, or movement of hard but not soft objects, or ... ?

with MHVR, having doors or windows open might be expected to affect
the pressure in the house ... so, all closed => some pressurisation,
maybe, depending on the relative speeds of the inlet & outlet
fans ... 'wonder if adding air-pressure-sensor(s) to each room could
be useful ... picking-up both level & fluctuations ... and so doors
open, people moving-about, curtains wafting, pesky flies, whatever ...

micro-phones are air-pressure sensors, of course ... wonder if a
broad or limited bandwidth one would be best ...

hmmm ... would fuzzy logic be the thing, to make it work ... looked-
up Wiki, but 'am really none the wiser, 'though it did mention
pattern recognition as being an application for it ...

rambling, sorry, but I feel there's a glimmer here !

or maybe I'm clutching at straws ...

Chris