Arduino RFID RC522 Authentication System

This project demonstrates how to use an RFID RC522 module with an Arduino to authenticate RFID cards. The system turns on a green LED if an authorized RFID card is scanned and turns on a red LED and activates a buzzer for unauthorized cards.

Features

• RFID Authentication: Reads the UID of an RFID card and compares it to predefined authorized UIDs.
• Feedback: Turns on a green LED for authorized cards, a red LED and buzzer for unauthorized ones.

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Components Required

• Arduino Uno (or any compatible board)
• RFID RC522 Module
• Green LED
• Red LED
• Buzzer
• Resistors (220Ω)
• Jumper Wires
• Breadboard

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Circuit Diagram

Refer to the included file: circuit.png for wiring details. Below is a summary of the connections:

RFID Pin	Arduino Pin
3.3V	3.3V
GND	GND
RST	Pin 9
SDA	Pin 10
MOSI	Pin 11
MISO	Pin 12
SCK	Pin 13

Other connections:

• Green LED: Connect to a digital pin (e.g., Pin 7) via a 220Ω resistor.
• Red LED: Connect to another digital pin (e.g., Pin 6) via a 220Ω resistor.
• Buzzer: Connect to a digital pin (e.g., Pin 5).

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How It Works

1. When an RFID card is brought near the RC522 module, its UID is read.
2. The UID is compared against a list of authorized UIDs stored in the code.
   • If authorized:
     • The green LED turns on for 3 seconds.
   • If unauthorized:
     • The red LED turns on for 3 seconds, and the buzzer beeps.

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Getting Started

1. Clone the Repository

2. Open the Code

Open code.ino in the Arduino IDE.

3. Install Required Libraries

Make sure the following libraries are installed in your Arduino IDE:

• SPI
• MFRC522

You can install them through the Arduino Library Manager (Sketch > Include Library > Manage Libraries).

4. Upload the Code

• Connect your Arduino board to your computer.
• Select the correct board and COM port in the Arduino IDE.
• Click Upload to flash the code to your Arduino.

5. Test the System

• Power the Arduino and connect all components as per the circuit diagram.
• Bring an RFID card near the module to test.

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Customization

• Change Authorized UID: Update the authorizedUID array in code.ino with your card's UID.
• LED and Buzzer Behavior: Modify the delay times or patterns in the code for LEDs and buzzer as needed.

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Troubleshooting

• RFID Not Detected: Check connections between the RFID module and Arduino. Ensure correct wiring of SCK, MISO, MOSI, and SDA pins.
• Incorrect UID: Ensure the RFID card's UID matches the one stored in authorizedUID.
• No LED/Buzzer Response: Verify connections and that the pins match those defined in the code.

Acknowledgments

• RFID Library: Thanks to Miguel Balboa's MFRC522 library for simplifying RFID communication with Arduino. Shri Harivansh, hope you like it !