--- Aaron <aaron.piclist@gmail.com> wrote:
> Stephen D. Barnes wrote:
> >Why not use a standard industrial retro-reflective (IR) sensor with the 
> 
> This is exactly what I was going to suggest, but OP should note that 
> these will detect anything that breaks the light beam.  People, etc.  
> You will also have to align the reflector and sensor every time it is moved.

Hey, that's a good point! There'll be lots of people walking about, going
to/from cars, there'll be children, couple of kiosks/vendors selling balloons,
sausages etc. But it's only cars they want to count.

-- Mark Scoville <mscoville@unicontrolinc.com> wrote:
> How about something air operated - like the old gas station drive over the

Yeah, I thought about those pressure hoses. The police(?) put them across roads
to monitor traffic. There are two snags with the hose idea, as I see it -->
1/ The ground in the car park (temporary venue) is soft in places. ie grass,
sandy soil etc. The wardens will move the flags + detectors etc about and you
don't know where, exactly.
2/ You don't want the tube getting snagged in cars' wheels or passersby
tripping over it.

So @ the mo' .... I'd say I'm leaning very much towards magnetic sensors. I
located a copy of that Silicon chip article in a local library, Jinx. Will go
dig it out today.
Debbie 



		
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