This is a multiple RFID Readers system designed specifically for an Escape Room. The door will open after the 4 right cards(Tags) are read and recognized.

• Arduino UNO.
• 4 x MFRC522 RFID Reader Modules.
• 13.56 MHz RFID key/card tags.
• Relay module.
• Leds.
• Jumper wires.
• Push button (for manual opening).

• Arduino IDE.
• Arduino RFID Library for MFRC522 by miguelbalboa.

• Green Led turns on when the door opens.
• Red Led blinks slowly two times when system needs more tags (less than 4 cards).
• Red Led blinks fast many times (4, maybe?) when the card isn't allowed.
• A push button added for manual opening (intended for the cleaning staff).

Do you want to see it working ? Check the video : https://www.youtube.com/watch?v=ahc8Yai_sWI