Anyone with more than one cat can tell you that the joy mischief they bring into your life is much more than twice that of a single cat. And if those felines have different dietary needs, you can end up where [Benjamin Krejci] found himself, which resulted in this fancy RFID cat feeder.
For a little backstory, [Ben]’s furry friends [Luna] and [Fermi] have vastly different eating styles, with the former being a grazer and the latter more of a “disordered eater,” to put it politely. [Fermi] tends to eat until she vomits, which is fun, and muscles her pickier sister away from the bowl if there’s anything left in it. [Ben]’s idea was to leverage [Luna]’s existing RFID chip, which he figured would be a breeze. But the vet-inserted chip is designed to be read by a high-power reader directly in contact with the cat’s skin, which made reliably reading the chip a challenge.
Several round of design iteration resulted in the current configuration, with a large antenna coil poised above and behind the food dispenser. [Luna] has no choice but to put the back of her neck and shoulder blades almost directly in contact with the coil, which makes it easier to read the 134.2-kHz chip with a long-distance RFID module. If [Luna]’s chip is found, the lid on the food bowl opens gently and quietly, so as not to spook the mild-mannered cat. The lid stays open as long as [Luna] is in place thanks to some IR sensors, but as soon as she backs out, the lid comes down to keep [Fermi] from gorging herself.
Hats off to [Ben] for working through the problem and coming up with what looks like a fine solution. We suppose he could have tried something easier like weighing the two cats to distinguish between them, but this seems like a cleaner solution to us.
Nice project. Thanks for sharing the long range RFID module!
I have a cat like Fermi. Her littermate has a much larger frame, but she’s overeaten to the point that their weight is pretty indistinguishable. I should try out something like this.
My cats have different chips, so that the vet needs different readers for them. Neither is RFID.
Yeah, my understanding is that animal microchips are not RFID and operate on a different frequency. Despite the scam phone apps claiming to read them with the RFID reader.
They are all RFID – RFID is the working principle, not a specific implementation. They use different protocols than other common RFID use cases though.
There are at least 2 different standards commonly in use in the US for pets, I think Europe mostly sticks to one. They are indeed RFID, but not the same frequency or protocol that your phone uses for NFC for example (nor your EZ-pass or security fobs for that matter). I lucked out that Luna is the one of my cats that is chipped. In fact, I never bothered to have the software verify that it’s her because my other cat doesn’t have one.
Have you had your cat’s thyroid levels checked? 😬
Like any good hack, I hope this is cheaper than equivalent commercial offerings (yes they exist).
For my cats, I’d have to mill this thing out of a single spiece of steel. Otherwise they’d quickly dismantle the entire affair…
I made a cell phone app that keeps Layla out of Foxy’s food bowl. The setup is basically an old cell phone mounted behind a feeder that I bought and modified to work with the app. Instead of RFID it uses facial recognition. Been using it for about a year now and it mostly works.