Schematic - http://hackerspace.lv/wp-content/uploads/2013/03/rfid_circuit_last.png
Features:
- EM4100 decoder
- 100 card memory
- serial output
Arduino pinout:
- 0 - serial RX
- 1 - serial TX
- 2 - administrative button
- 4 - RFID input
- 5 - buzzer
- 6 - door lock
- 7 - red LED (cathode)
- 8 - green LED (cathode)
- 11 - 125 kHz output