Arduino code for a simple nfc door lock.
This code uses the Adafruit NFC shield library located at https://github.com/adafruit/Adafruit_NFCShield_I2C.
I used an Arduino Uno, Adafruit NFC Shield, and a Lock-style Solenoid. Check the schematic or fritzing files for more info.
Open the file in your arduino dev environment, change the NFC tag IDS, and compile/upload it to your board.
Pictures and description can be found at mtmosier.com.