RFID Reader Olimex MOD

Compact USB 125kHz RFID Reader.

  • USB plug in module, works with every USB host which supports HID Keyboard and CDC
  • Built-in 125kHz antenna
  • Read RFID125 kHz tags from up to 5-15 cm distance
  • Emulates USB keyboard or Virtual COM port
  • 50x20x5mm (2.0x0.8x0.2")

RFID Reader Olimex MOD Product Help and Resources

Core Skill: Electrical Prototyping

If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.

1 Electrical Prototyping

Skill Level: Noob - You don't need to reference a datasheet, but you will need to know basic power requirements.
See all skill levels


Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

  • Member #823386 / about 6 years ago / 1

    Hi, I'm new with the RFID stuff and i would like to try thgis product. Coul you let me know if it is compatible with Mac OSx.

    Thanks in advance, Maurício Rodrigues

  • aliali / about 12 years ago / 2

    Range on this thing is AWFUL. Can't even read the RFID tag in my hand when it's pressed up against it.
    My hands may be chubby, but even with a rfid card or tag it's barely 1 cm.
    Got seriously ripped off by this.

  • PaulF91 / about 12 years ago / 2

    Wow. The range is an awful lie. 5-15 cm? Yeah right, it's barely 3 cm. Sparkfun, PLEASE update this page to reflect the REAL range so no one else gets scammed.
    I'm trying to make a better coil for it and trying the capacitor trick.

  • RFIDDave / about 13 years ago / 2

    Some of the readers on my last order had a new 1.02 firmware version that no longer provides endian-flipped hex output when decoding a badge. This means that older units (firmware 1.00) and newer units may produce completely different output for the same RFID tag. Any application designed for the original 1.00 firmware units may need to change for the new 1.02 firmware.
    Also, I've tested more than 50 of these units. For me, read range is more like 2-3cm. If you need more, and you're willing to void your warranty, I've found that the range can be approximately doubled simply by soldering a 1000uF low-ESR cap in parallel with C8.

    • Hi
      I'm experiencing some unexpected behaviour in the Olimex RFID-125 USB-stick, and I thought maybe you could help me out here :)
      It reads my RFID cards like it should and reports back through the serial communication stuff, but after a little while it just shuts down and turns off the red and green LEDs. All communication with the USB stick stops here. Same experience under Linux and Windows 7. Windows starts complaining that the device doesn't work properly, and then it's suddenly listed as an unknown device. Linux just shuts down the communication with the serial device with an I/O error (and removes the /dev/ttyACM0 once in a while). So I'm guessing it's got nothing to do with the operating system or drivers. I tried updating the firmware, which went fine, but the device acts the exact same way as before. Do you have any clue as to what could be wrong?

  • Chulla / about 8 years ago / 1

    Today i tried to desolder the antenna and used dupont wires to seperate the controller and antenna. Its found working. Now going to make a new antenna with same inductance. Once thing that is buzzing me, The reader sends report after every 1 second. can it be make faster.

  • Chulla / about 8 years ago / 1

    How can we use USB host sheild to read data from RFID reader, any specfic liberary, Also what mode should be used, HID or CDC.

  • Member #355581 / about 9 years ago / 1

    How does this reader handle two cards in the field at the same time? Does the reader read one, both or neither?

    Can this be easily interfaced with an arduino? I need a very narrow reader module.



    • Member #435690 / about 9 years ago / 1

      To interface this with a arduino you would need a USB host shield. https://www.sparkfun.com/products/9947

      • Chulla / about 8 years ago / 1

        How can we use USB host sheild to read data from RFID reader, any specfic liberary, Also what mode should be used, HID or CDC.

  • Member #331894 / about 9 years ago / 1

    Hi there,

    I need to read 125Khz proximity cards (Type NexWatch). I am currently using pcprox RDR-6N81AKU which is above 200$ ( http://www.rfideas.com/support/clients/Sharp/part_numbers.php )

    I am not sure whether type is an important thing to consider while buying the card readers? Please let me know if this card reader can ready any 125Khz proximity cards.

    Thank you, Kris

  • pku / about 9 years ago * / 1

    I've started a medical simulation project that uses this part at its core (edus2). Thanks for continuing to source this SparkFun. It's making it easy for other groups to build the system on their own.

    The part performs perfectly for our needs. Some users have hacked the antenna to get a little more range and make the device fit into different cases. There have been 15+ units bought for our project and it's clones and everyone has said they are working well. (We have a fairly specific application, see the above website).

    As for edus2, the code works, but is not pretty. Any help from interested parties is welcome.

  • CapitalV / about 11 years ago / 1

    For people with range problems. I found that it differs a lot from computer to computer and I think it has to do with the amount of power the usb port can deliver. You can extend this by not making it read continuously but only twice a second.

  • Member #209445 / about 11 years ago / 1

    This thing doesnt even show up in my Device Manager, even after a reboot with it plugged in. swiping my RFID cards across it produces no response, ZERO! the lights dont even flicker.
    I am asking for my money back

  • thisupend / about 12 years ago / 1

    is there anyway of turning off carriage return in usb hid mode, I'm trying to use it for secure logon over usb inside a netbook

  • edbarnard / about 12 years ago / 1

    Does the virtual COM port work under linux or MacOS X?

    • RFIDDave / about 12 years ago / 1

      I've had no problems using both USB Hid and Virtual COM under Linux. I've only tested on OpenSuSE 11.1/11.2, but I'd expect any recent kernel to work. The device appears as /dev/ttyACM0

  • Daniel Eriksson / about 13 years ago / 1

    Hi. Do you know where I can find the latest image firmware for this decive?

  • johnp / about 13 years ago / 1

    Can the UART be accessed with this model? It looks like there isn't an external connector as with the -BOX variant. Perhaps the connections are available on the board underall that heat-shrink?

    • RFIDDave / about 13 years ago / 1

      There are pads labeled "_TXD" and "_RXD" along with "GND" and "+5V" on the bottom of the PCB along the back edge by the button. Presumably, these are the pins needed for UART mode.

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