Finding lost keys

[abreauj-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (John Abreau)]

I've had similar thoughts, but I was thinking in terms of tagging thousands
of items, and the cost isn't cheap enough for that. I'd like to tag almost
everything; each book, each DVD, each small device, the remotes for
the TV, stereo, etc.; any item small enough to misplace.

If each tag costs a penny, then tagging 10,000 items would cost $100.
If each tag costs a dollar, the cost becomes prohibitive.


On Thu, May 6, 2010 at 2:26 PM, Tom Metro <tmetro-blu-5a1Jt6qxUNc at public.gmane.org> wrote:
> Doug wrote:
>> ...there is an RFID FOB thing on my keychain for the gym. ?Is it
>> possible to find the FOB with some source of radio
>> transmitter/receiver thingie?
>
> I've considered this sort of thing myself, because they would offer some
> advantages over traditional key finder devices:
>
> -RFID tags are cheap, so it would be economical to attach them to dozens
> of items, not just a few high-value items, like your keys.
>
> -each tag has a unique serial number, so in theory you could walk into a
> room with a scanner and instantly get an inventory of all your tagged items.
>
> -they don't use batteries. One less battery to change every few years.
>
> -they're smaller than typical RF key finder devices.
>
> I've suggested this approach to one of the small manufacturers of key
> finders. Probably something they had already considered. I didn't get a
> response, but I suspect...
>
> Building the detector is probably not cost effective currently. Or it
> would have impractical physical proportions. The challenge is that you
> need to transmit enough RF energy to the tag in order for it to power up
> and send back a reply. To cover a large area that either requires a
> large antenna or scanning the space with a small antenna within inches
> of the tag.
>
> Supposedly the shipping industry does have systems that can read RFIDs
> from a pallet of merchandise, but I believe they use rather large
> antenna loops to accomplish that. Probably with a diameter measured in
> feet. And even then, I suspect it wouldn't cover the square footage of a
> typical residential room.
>
> I believe the hand-held reader guns, that you might have seen, have
> rather short range, and the people tracking RF tags (the kind you use to
> locate where someone is in a building; not the kind that you wave near a
> reader to open a door) used in some businesses and universities are
> probably actively powered.
>
> I imagine if you wanted to install a loop of wire in each of your rooms
> (say tucked under the crown molding), you could build your own working
> system. :-)
>
> ?-Tom
>
> --
> Tom Metro
> Venture Logic, Newton, MA, USA
> "Enterprise solutions through open source."
> Professional Profile: http://tmetro.venturelogic.com/
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-- 
John Abreau / Executive Director, Boston Linux & Unix
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