• badweasel commented on landmanr's instructable RFID cat door6 months ago
    RFID cat door

    Did you ever figure it out? I'm having the same issue where I need a larger antenna, except that I'm not getting anything at all with mine.

    I'm trying to build this project except that I already have an electronic dog door mechanism. The door I have uses an ultrasonic collar to trigger the door and it's super finicky, the dog collar is large for a small dog, and the batteries are proprietary and ultra expensive. So my goal is to hack the door I already have to use RFID instead of ultrasonic.The exiting through the door part is easy. I'm using a micro PIR sensor for that and it works great. The coming back in will need the RFID and the reader and antenna I have is very short range. I belive it's the same one used in this project. I have to place the tag right on the antenna. Although to be fair I have been powering it over USB. I tried to build my own antenna using the same sized wire and method shown here (10x10 inch square at 24 winds) but with that one it doesn't read anything at all. I also don't have equiment to measure inductance (that I know of).I've looked at the microchip pdf but it's over my head. I wish I could just buy a large antenna that I could use that would read the dog tag at the distance I need.

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