Longer Range RFID

Discussion in 'Wireless & RF Design' started by Nuno Silva, Oct 12, 2016.

  1. Nuno Silva

    Thread Starter New Member

    Sep 26, 2016
    7
    0
    Hi.
    I am planning to build a raspberry pi controlled cat door. I want to allow the entrance/leaving of a cat based on it's proximity. I figured out that the way to go was RFID. However, since a cat can't be taught to go near the RFID reader to unlock the door, and since all RFID readers I have found have a very small range (up to 3cm) this doesn't work.
    I was hoping that some of you knew any option to either extend the range of a MIFARE RC522 or any other similar option with a higher range even if a little bit pricier.
    Thanks
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,001
    3,756
    Look for Active RFID. They have a battery, Chip and antenna coil and, therefore, Much more range. The passive RFID are energized by the reader coil the range is much less. Just antenna (also functions as energizing coil) and chip.

    Good luck.
     
  3. RichardO

    Well-Known Member

    May 4, 2013
    1,231
    382
    Maybe you need to train the cat better. :D

    I worked with a gal whose cat rang the doorbell to get in! There was a railing next to the doorbell button. The cat found out that if it jumped up on the railing and rubbed against the button somebody would come to the door.
     
  4. Nuno Silva

    Thread Starter New Member

    Sep 26, 2016
    7
    0
    Can I use an active tag with any normal reader if the frequency is the same?
     
  5. Nuno Silva

    Thread Starter New Member

    Sep 26, 2016
    7
    0
    Well it's for a school project so I can't train all the cats in the world :-D Thanks anyway,
     
  6. inwo

    Well-Known Member

    Nov 7, 2013
    2,433
    315
    I just got in a rfid system that worked from >5M. Had to adjust to minimum. Now about 1M.
    As per GopherT active system.
    Found it on Ebay.
     
    GopherT likes this.
  7. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,001
    3,756
    I think the passive systems work on higher frequencies (in general) that active systems. Lower frequency yields better battery life for the tag than a higher frequency - if I remember correctly.
     
  8. Nuno Silva

    Thread Starter New Member

    Sep 26, 2016
    7
    0
    Yes that's true. I researched deeper and found that they wouldn't work together. Back to square one I guess, since an active reader is too expensive for the project...
     
  9. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,001
    3,756
    @inwo could you post a link to the 5meter RFID kit on eBay? Thanks.
     
  10. Nuno Silva

    Thread Starter New Member

    Sep 26, 2016
    7
    0
    That would help a lot since I can't find one. Thanks to both.
     
Loading...