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 (RFIDGeek.com) 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?)

1.  
2.  
3.  
4.  
5. SPI Clock Out from FM1702NL Pin 24

J4: RS232 I/O

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