Ginger cat detector

This is a solved problem with a COTS solution!

Nice problem, I was thinking of two sprung flaps mounted vertically above one another. The cat's enter the top and the skinny one will walk straight across into the house. The fat one will fall through the first and second flaps and then through into the house. The ginger one will fall through the first but not the second and from there can only go back out of the house! Just need to tune the spring rates.

I suppose an electronic version would be to have some mass measurement that determines which cat it is then opens the appropriate flap to the house or back outside.

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Cats don't care for funhouse rides; I think this mechanism will train them all to just stand outside and mew :)

Put rubber booties on your cats and electrify the floor. Ginger cat will only visit once!

Chris

If you find a solution, I'd be interested in knowing the answer. In our case, our cat is "normal" and the unwanted one is quite furry. All cats are gray in the dark.

I gotta say - the replies in this thread are the very soul and definition of what engineering is all about!

That was going to be my suggestion.

-- Grant Edwards grante Yow! Give them RADAR-GUIDED at SKEE-BALL LANES and visi.com VELVEETA BURRITOS!!

If they were, I assume the range of a chip reader would be enough that you could put one in the "roof" of a cat-sized tunnel and fix it up so that the door would only open if the proper cat is in the tunnel.

How much does it cost to get a pet chipped?

Are readers available in a hackable form?

Typically between $20 and $60 depending on how much your local vet feels his time is worth. Almost all animals that have been adopted from shelters will be supplied with the chip preinstalled.

Readers are given gratis to animal shelters, but there is no unified standard (!!!!!!) so several readers are required. Fortunately there are open-source projects

Presumably the OP would get the same brand of chips in both his cats and only require one reader.

Intersting. It looks like he's using 1N914 diodes (or something equivalent) to clamp the audio line level output. The odd thing is that he uses five of them arranged like this:

| | +---->|-----+ | | +---->|-----+ | | +---->|-----+ | | +----|

On that sort of crappy breadboard you need 5 just to be sure one of them makes contact :)

To: John Devereux From: Grant Edwards Subject: Re: Ginger cat detector In-Reply-To: References:

Back in the college days, there was nothing quite like troubleshooting those multi-breadboard rat's nest design projects.

Buy a Border Terrier and socialize him with your cat only.

Use the flap as a trigger for a camera, send the photo to a PC where a program will analyse the color spectrum, release a fake mechanical mouse that will lead the ginger cat to the terrier and hope that the cat's owner is not a lawyer.

Weighing the cat is one option ?.

Or, Door switch+wakeup, and that would give you the satisfaction of Launching, and SEEING the 'counter measures' kick in :)

We had a similar problem, but I swear the rogue cat was psychic. As soon as the plan was in place, he was never seen again!

-jg

Weighing the cats is a simple and obvious solution and if it works could be very reliable. It depends on how similar the cats are in weight and how much they vary day to day.

ISTR hearing that certain parole offices in the States measure galvanic skin response to identify offenders. It could conceivably be used on the cat's paws although I suspect it would vary far too much to be useful with wet and/or muddy feet.

Sample the cat's miaow and run it through an FFT. I must admit that I have never actually studied the finer points of noises made by cats, but I wouldn't be surprised if you found that each cat's miaow had a distinctive signature. Of course this depends on the cat miaowing in the first place but in my experience that is rarely a problem when they want to be let in.

I've known a cat ot two that wouldn't. They'd just sit on the window ledge and stare.

Might be interesting to see how unique a meow-print was though.

Robert

That is ecause they wanted to be let in through the window and not the door. BTDT.

I'm a bit sensitive on the subject of pet cats lately.