PetPass Animal RFID Reader

The PetPass Animal RFID Reader is based on the MultiPass Universal RFID Reader. Its hardware design is exactly the same, with only changes to the firmware.

PetPass is a handheld RFID reader which can be used to detect and decode the FDX-B RFID tags normally implanted into necks of pets (normally dogs and cats) as a form of identification.

PetPass is intended to be used as a portable handheld device, which is different from the indented use of the Multipass which intention is based more on a type of generic/universal RFID reader for access control.

PetPass – Prototype 1 shown below was still constructed using vero-board, a pcb design will be used in future revisions of the board.

PetPass -Prototype1
PetPass animal RFID reader -Prototype1


  • Switch on the device, the LCD will display “Reader Ready”
  • Attempt to scan the animal, move the reader in a search pattern between the shoulder blades and neck area on the animal
  • The reading led (red) will start to flash once a RFID tag is detected
  • At this point it reader’s coil must pass perpendicular over the tag to get maximum magnetic coupling
  • Once the reader gets a valid read, the Detected led (green) light and the unit will beep, and at the same time display the detected tag number on the LCD,
  • press the clear button on the side of the device to clear the display and return to the “Reader Ready” state.
  • the sound can be enabled/disabled by holding the clear button when powering on the device, once the “Reader ready” is displayed the button can be released. The device will now display a “M” in the top right corner if muted, and no “M” is displays when not muted. The device will remember the mute state even if powered down and up. To change the Mute state, the button must again be pressed while powering on.


The enclosure for the device is selected based on the following criteria:

  • small enough to be used as a handheld device
  • big enough to house all the components
  • have a battery compartment with lid for a 9V battery (This is important to eliminate the need to expose the inside of the case when replacing the battery).
  • big/small enough to fit the 16×2 LCD display (the display window had to be cut, since no case was available with a pre-cut window)


  • Only detect and decoding FDX-B chips (FDX-B Protocol description)
  • Read range is limited, approximately 1cm max ( between reader and chip, not reader and skin)


Below is a video demonstrating the use of the PetPass – Prototype 1 reading an FDX-B chip.

Demo board and coil

PetPass Demo PCB Board
PetPass Demo PCB Board
Demo Coil
Demo Coil


Source Code

The source code which is part of the design/manufacture packages can be purchased from Gizmoshop

This source code or circuit or any parts of it is not allowed to be used in any form of commercial application without written permission from the author.

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