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RFIDGeek/Univelop RF500B RFID Module

RFIDGeek/Univelop RF500B RFID Module

This is the RFID Module sold by RFIDGeek/Univelop Tech. While this little module might not look like much, it IS true what they say, “Good things come in small packages”.

By wiring +5 and Ground, as well as RS232 RX and TX to the board, you can use the included program to read and write to/from MiFare cards.

The company website ( does not do the module justice. This little ~1.35″*2.25″ RFID reader/writer module packs the following onboard:

Top Side:

  • Fudan Microelectronics FM1702NL (32-pin SOP): [PDF] Parallel or SPI Interface (Note, the higher models, FM1715NL and FM1725NL both share a common pinout, and offer increased features [see the PDF]. I wonder if the board would work with one of these instead of the FM1702…)
  • 13.56Mhz Crystal
  • Sipex SP232EEN: TTL-RS232 Converter

Bottom Side:

  • LSI 1021WI?: (8-pin SOP, bottom side of the module)
  • Unknown Microcontroller: (44-pin, ID has been shaved off)
  • 11.0592Mhz Crystal

There is space available to add pin headers to the board for each of the following: (All of these are subject to change and/or verification)

J1: Antenna Interface

  1. Ground
  2. Transmitting Antenna 1
  3. Ground
  4. Transmitting Antenna 2
  5. Ground
  6. Receiving Antenna

J2: Microcontroller Interface

  1. Control Output
  2. Buzzer Output (High)
  3. RS485 Control (Low)
  4. VCC
  5. Reset Onboard MCU (High)
  6. Ground
  7. UART Receive
  8. UART Transmit

J3: Microcontroller SPI? (For the “Module 500” Only?)

  5. SPI Clock Out from FM1702NL Pin 24

J4: RS232 I/O

  1. VCC (+5V)
  2. RS232 Receive
  3. RS232 Transmit
  4. Ground