Introduction: 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...

****** CONTENT REMOVED - SEE BELOW ******

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

Materials


  • 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.

Tools

  • 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.