Long have I wanted a cat door that would only open for my cats, not the mean neighborhood one that eats their food. I can’t be the only one. I’ve been meaning to try to build one with a camera, rPi and Google Coral, but never got around to it. There’s the matter of the locking mechanism and more.

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DannyBee 2 days ago | parent | next [-]

I have built two of these for dogs. It's really not hard,w hether you go completely from scratch or use something premade.

If you want something mostly premade,go get an autoslide. If you want to do it completely from scratch:

1. RFID/bluetooth proximity is much easier to work with than camera + rpi + AI. For the usecase you are talking about, AI is not just overkill, but will make it actively harder to achieve your goal

2. Locking is pretty easy depending on motor mechanism - either a cheap relay'd magnetic lock, or simply a motor that can't be backdriven easily.

Motor wise, you can either use the rack and pinion style that autoslide does, or a simple linear motor if you don't want to deal with gear tracks.

Overall, i went the autoslide route and had it all set up and working in an hour or two.

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darkwater 3 days ago | parent | prev | next [-]

That's t'he definition of (entertaining) overengineering: since every house cat should have an RFID chip already, there are doors that use that already. 4 AA batteries, "low-tech" enough, it just works

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sillysaurusx 3 days ago | parent [-]

How do you interface with your cat’s chip? Mine is chipped but it never occurred to me to build a detector.

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darkwater 3 days ago | parent | next [-]

In my case I bought a pre-built solution by PetSafe that works pretty well. You scan the catś chip once and it recognizes him/her each time they try to enter. It supports up to 10 cats IIRC

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donavanm 3 days ago | parent | prev | next [-]

You can get off the shelf doors and feeders. I use “sureflap.” The rfid pellets vary slightly based on locale and age, but probably 125 or 132khz. You can get them off of ebay if you want an easier test case. Handheld cheap scanners are about $20.

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DannyBee 2 days ago | parent | prev [-]

125khz reader. The real problem is distance most of the time. Cats are curious enough about the doors that they will go right next to them. Most dogs won't.

	▲	Doxin 2 days ago \| parent [-]
		Luckily dogs are usually pretty easy to train. My dog will tap the glass on the back door if he wants out. I'm sure I could get him to "present his chip" to a doggie door within a couple of days.

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Findecanor 3 days ago | parent | prev | next [-]

Long ago I read about an automatic cat door that operated simply on the colour of the cat. It worked because the cat was the only red cat in the neighbourhood.

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dehrmann 3 days ago | parent | prev [-]

Take a look at SureFlap and OnlyCat. They use RFID chips in the cats.

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throwaway290 3 days ago | parent [-]

Until the neighborhood bully gets a hold of a flipper and shakes down well cared cats for copies of their rfid chips.... sorry

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YPPH 3 days ago | parent [-]

A neighbourhood bully could do far worse things to a cat that involves little to no technology. One of many reasons why my cat stays inside.

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sillysaurusx 3 days ago | parent [-]

Also for your own sanity, mostly. I always wonder if mine will come back each night. Thus far he hasn’t disappointed, but I’m braced for that day.

That said, some people vehemently argue that it’s abus{e,ive} to let cats wander the neighborhood, so thank you for not trying to tell others what to do. It’s become so common that I’m braced for it every time this topic comes up.

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hdgvhicv 3 days ago | parent | next [-]

Seems more abusive to keep a cat indoors its entire life.

	▲	throwaway290 2 days ago \| parent [-]
		keeping a street cat locked in the house is maybe about as cruel as to let a house cat roam on the street.

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throwaway290 3 days ago | parent | prev [-]

Guys come on I was joking, just had that funny image of neighborhood stray flipping chips from house cats