I just received my RC522 RFID reader and made this simple Arduino access control system that uses the reader, a buzzer for the alarm and a relay shield for the security system. The relay can be used ...

MFRC522 Arduino library for MFRC522 and other RFID RC522 based modules. Read and write different types of Radio-Frequency IDentification (RFID) cards on your Arduino using a RC522 based reader ...