Serial EM4100 RFID Card Reader Module (without tags)

$52.19 ea

  • Part no.: 2109237
  • Manufacturer: Parallax
  • Manufacturer no.: 28140
  • RoHS Compliant
  • NCNR (Non-Cancelable, Non Returnable)
# of units Price
1+ $52.19
5+ $49.59

Request a Large Quantity Quote

Serial EM4100 RFID Card Reader Module (without tags)

The RFID Reader Module can be used in a wide variety of hobbyist and commercial applications, including access control, automatic identification, robotics, navigation, inventory tracking, payment systems, and car immobilization. (This item is the module only and does not include RFID tags, see compatible tags below. The Serial RFID Card Reader Module with 4 Tag sampler pack is also available.) There are a variety of transponder tags that come in different packages. Each tag has a specific range that is within 10% of the given distance for each type of tag. The reason for the 10% is due to environmental conditions and RFID modules.


  • Low-cost method for reading passive RFID EM4100 family transponder tags
  • 2400 baud serial interface
  • Enable input allows module to be enabled/disabled by software
  • Bi-color LED for visual indication of status

    Application Ideas

  • Robotics
  • Payment Systems
  • Automatic Identification Note:
  • No tags are included with the RFID Reader Module.
  • This device can be connected to a PC serial port using a MAX232 line driver. The circuit isn't supported by Parallax, but it's possible to make this connection with a few dollars of parts or by using the USB version of the reader. There is an outline of connections on the forums.


  • Reads 125 kHz Tags, EM41000 Family
  • Power requirements: 4.5 to 5.5 VDC
  • Communication: Serial at 2400 baud (8N1)
  • Dimensions: 2.45 x 6.25 x 0.22 in (62.2 x 82.5 x 5.57 mm)
  • Operating temp range: -40 to +185°F (-40 to +85°C)

    Compatible tags:

  • 54x85mm Rectangle Tag ISO Card: 6.3cm (2.5") ±10%
  • 50mm Round Tag World Tag (#28142) 50mm: 6.8cm (2.7") ±10%
  • Blue Eye Key Fob
  • 30mm Epoxy Disk Tag 64-bit

    Downloads & Resources

  • RFID Arduino Example Code
  • RFID BS1 Source Code
  • RFID BS2 Example Code
  • Open Communication - RFID (Nuts & Volts Article)
  • RFID Card Reader Documentation
  • RFID Card Reader SXB Code
  • RFID Card Security SXB Code
  • RFID Reader Software for Windows [by SavageCircuits]
  • EDN Article: RFID in Embedded Designs: Your Move
  • RFID and Text-to-Speech Modules Video Podcast

    Report a problem
    Suggest a product
  • No specifications are available at this time. Call for more information.

    Report a problem
    Suggest a product

    Related products

    $15.95 ea

    $4.49 ea