How to Make a RFID Pet Food Access Control System




In this instructable I will explain how to make a simple RFID pet food access control system. This system uses a stand-alone RFID system that can be purchased either pre-assembled or in kit form if you desire to do the soldering yourself, and also wish to save a few dollars in the process.

The reason I made this was out of pure necessity. I have two dogs, and when my vet placed one of them on a special diet I needed some way to ensure they ate their own food... and only their own food. Since they are open-bowl fed and I'm gone part of the day, I decided to look for a product that would do what I needed. This meant I wouldn't have to spend a great deal of time trying to re-train them and still give them the freedom to eat whenever they chose. This is where my frustrations begun...


Frustrated with the situation, I decided to roll my own. This first version does the job, but I would eventually like to make the antenna extend around the entire perimeter of the bowl. If anyone has experience with RFID technology, I would appreciate any feedback that would assist in modifying the antenna into that configuration.

***** UPDATE *****
Anthony Targa, holder of patent #5570655 contacted me. Apparently he DID manufacture the device and it was featured in numerous Veterinary publications. Because of this, I fully retract my "patent troll" statement. I simply wish Anthony's device was produced on a larger scale so more people could have access to it.

Step 1: Materials and Tools


  • SK02 - 125 kHz Proximity Key Fob
    • The smallest quantity sold is a 10 pack. I asked QKits if they would substitute the access cards that come with the kit for the key fobs, and they did... I'm not sure if this was a "one off" case, but it doesn't hurt to ask. If they won't do this for you try contacting AVEA, the mfgr of the kit and see if you can purchase from them.

  • Project box
    • The dimensions of the box I used are 13cm x 7cm and was purchased at a local electronics dealer, but you can also buy them at Radio Shack.
    • The KL042 circuit board can be cut down to a min. size of 9cm x 5.7cm, so make sure your box is at least this size PLUS the dimension of your adaptaplug and buzzers.

  • Annoying buzzer(s)
    • Also available at Radio Shack

  • Wire or L-Bracket
    • Used to secure the box to the food bowl. I bent one side of an l-bracket to make a hook shape.


  • Dremel
    • In case you decide to resize the circuit board.

  • Hot glue gun

  • Drill
    • For adding the sound and adaptaplug holes. You can also use your Dremel if you have the bits.

  • Soldering gun & solder
    • If you buy the unassembled version of the kit.

Step 2: Assembly

There isn't much to this step. If you purchased the unassembled version of the kit, consult the diagram that's included with the kit and put it together.

Then, have a look at the pictures below to put it all together.

Before you close the box, program the RFID key fobs via the DIP switches. Consult the manual that comes with the kit for this.

You need to program the RFID key fobs that DO NOT have access to the bowl. This way, when the pet who DOES have access to the bowl tries to eat nothing will happen... but when a pet who DOES NOT have access to the bowl, a successful read will occur and the buzzers will sound.

Step 3: Attachment and Positioning

I used the modified l-bracket I mentioned in step 1 to attach the box to to the bowl. Of course, you can do whatever you want.

Then I cut a slit in the charcoal colored mat and ran the power cord underneath for safety reasons.

All that's left to do is position the box so the key fob hovers over the box while the dog eats!

I hope this helps other pet owners who are in my situation. Please feel free to comment and suggest modifications.



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    60 Discussions


    11 years ago on Step 1

    Ummm... Not as a complaint, but you and others that use acronyms might define them in parentheses so those of us who are unfamiliar with that particular condensed term might also follow. Such as: Building a ULDB (Ultra Light Displacement Boat) is easy when you have a good instructable.

    3 replies

    Reply 3 years ago

    Wireless Whiskers is a very sophisticated patented RFID feeder in high volume production with many unique capabilities:


    Reply 9 years ago on Step 1

    Mex: Most acronyms are easily identifiable by cutting and pasting them into google. No offense meant, but to have every acronym spelled out would defeat the purpose of using acronyms, of which RFID in particular is a hugely widespread acronym, and only takes 3 seconds to find out what it is.


    Reply 6 years ago on Introduction

    aqwiz, I think Mex is probably suggesting you only do that for the first time the acronym appears, thereafter just write the acronym. I'm currently reading a book where the author eventually lets us into what the acronym stands for, if ever - very frustrating! For those of us who have missed some of the hugely widespread acronyms,  the words "Radio Frequency Identification" in parentheses the first time the acronym appears, would allow us to get on with enjoying an Instructable without having to stop to check out what the heck RFID stands for.
    Took me 7 seconds...  ; ]


    Totally groking this idea - I've two cats - one of which like to steal the other's food, and knock the water dish about. I'm going to put both food/water bowls in a separate box for each cat - and make both lids openable via the RFID tag on their respective cat's collar. This should stop our big boy from knocking the food and water dish about, as I can make the boxes with plenty of weight - and he quite literally can't access his step-sister's food.

    Thank you for the wonderful idea! I'm sure this is the solution to the issue at our house.


    8 years ago on Introduction

    Aas an alternative for a brush (which may be difficult to clean), a carousel of some sort or even an Archimedian screw in a tube. Obviously, they both will require some sort of timing.


    8 years ago on Introduction

    is there a way that this device could be battery operated?


    8 years ago on Introduction

     There is another option for people who need to keep certain pets away from either food or cat litter. Check out They offer a product that will work for cats or small dogs. It's new, so I imagine at some point they'll offer larger ones as well. My roommate uses two of them. One to keep his dog out of the cats' food, and the other to keep the same dog out of the cats' litter. It's a bit spendy $150, but he said the $300 he paid for both has saved his sanity, and his dog hasn't been sick from eating cat feces and cat poop since he started using them. These units work with magnetic door openers, but I've ordered one from them special to use with an rfid door since my cat needs to eat different food from his, so my cat has a different access than his cats, and they can't eat my cat's food. I'm paying a bit more to get the rfid model $210, but I see what it's done for my roommate, and it's well worth it in my opinion. They also look pretty classy. check it out.

    why not replace the buzzer with a recording of "the mosquito sound"?....this is VERY annoying to people AND dogs and sometimes even painful.

    4 replies

    Audacity can be used to generate a tone of the appropriate pitch.

    Unless the sound is extremely intense, humans cannot usually hear sounds over 20,000 Hz. For comparison, the whistle created by an old CRT television screen is around 16,000 Hz.

    Remember that your sampling rate must be at least twice the highest frequency in your sound. For example, if your rate is 44,100 samples per second, sounds with frequencies over 22,050 Hz will either be cut off or replaced with a lower-pitched sound (aliasing).


    10 years ago on Introduction

    How hard do you think it would be to use one of these as a car ignition?


    10 years ago on Introduction

    I think another avenue for creating one of these is to use a kit I found on eBay that is designed for controlling an electronic door lock. The kit cost $32.00 including shipping. It requires a 12v power supply and provides Normally Open and Normally Closed 12v outputs that are activated by a key fob. The controller has two antennas. The kit comes with 5 key fobs. The eBay seller is "kawalock," but please note that I have NOT received my kit yet and do NOT vouch for this seller. The kit looks promising though!


    10 years ago on Introduction

    This reminds me that I have a pet electric dog door i had to take out because the collar device stopped working for one dog, I had bought tons of batteries for these collar devices, does anyone need the batteries? Batteries bought in quantity for the other pet door are: i have at least 18 batteries with 2016 expriration, duracell: DL2430B. Does anyone know what other devices use this battery? i hope i'm not overstepping any rules. Also, I bought a staywell infra red door and do not use the collar devices, never got them returned, i have 3 with batteries, never used, for use with 861 infra red dog doors. BTW I LOVE my two solopetdoors.


    11 years ago on Introduction

    I so came up with this idea! Then did a patent search and found out someone already had...bummer, there went my millions. I seriously need to make a pair of these for my cats. One is on a diet, and the other should be able to eat whenever she wants. I'd have to make one bowl that closes any time the diet cat gets near it, and another that opens for him on a timed schedule. Thanks for the inspiration!


    11 years ago on Introduction

    Can you please give me the circuit diagram of this project and the program if possible? I really need to have this information. Please help. thank you


    11 years ago on Introduction

    This RFID collar tags sure would work better than the infrared cat doors I presently have. I was planning on using a couple of pet doors to control access to some rooms I wanted to keep selected cats out of but I have found some cross-over between the colors of the infrared tags. The yellow tag is activating the blue keyed door. Plus you have to keep loading them with watch-sized batteries. Yuck! But like the dog bowl antenna, the cat door would need a little bit greater reach for the antenna. Would the stock antenna cover the lower, inner curve of the pet door so when the pet approaches the dangling tag touches the perimeter and the door unlocks?