RFID_UID-ARDUINO

To know your RFID Card UID by this code

RFID UID Reader using Arduino and MFRC522

This project reads the UID of an RFID card using an MFRC522 reader and displays it on the Serial Monitor. It uses SPI communication and is compatible with Arduino Uno, Nano, or any board that supports SPI.

🛠️ Components Required

Component	Quantity
Arduino Uno/Nano	1
MFRC522 RFID Reader	1
RFID Tag/Card	1+
Jumper Wires	As needed
Breadboard (optional)	1

🔌 Circuit Connections

MFRC522 Pin	Arduino Pin
SDA (SS)	D10
SCK	D13
MOSI	D11
MISO	D12
RST	D9
VCC	3.3V
GND	GND

⚠️ Important: Power the MFRC522 with 3.3V, not 5V. Using 5V may damage the module.

📟 Code Overview

This sketch initializes the RFID reader and continuously checks for RFID cards. When a card is detected, its UID is printed on the serial monitor in HEX format.

✅ Arduino Code

#include <SPI.h>
#include <MFRC522.h>

#define SS_PIN 10   // Connect SDA to D10
#define RST_PIN 9   // Connect RST to D9

MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance

void setup() {
  Serial.begin(115200); // Start serial communication
  SPI.begin();          // Start SPI bus
  mfrc522.PCD_Init();   // Initialize RFID reader
  
  Serial.println("Scan your RFID card to read UID...");
}

void loop() {
  // Look for a new RFID card
  if (mfrc522.PICC_IsNewCardPresent()) {
    // If a card is found, read its UID
    if (mfrc522.PICC_ReadCardSerial()) {
      Serial.print("UID of the card: ");
      
      // Print the UID
      for (byte i = 0; i < mfrc522.uid.size; i++) {
        Serial.print(mfrc522.uid.uidByte[i], HEX);
        Serial.print(" ");
      }
      
      Serial.println(); // Newline after printing UID
      delay(1000); // Wait a second before reading again
    }
  }
}

Serial Output When you open the Serial Monitor at 115200 baud, and scan an RFID card, you’ll see:

Scan your RFID card to read UID... UID of the card: E3 88 39 DA

Libraries Used MFRC522 by Miguel Balboa 🔗 https://github.com/miguelbalboa/rfid

SPI (built-in Arduino library)

Install MFRC522 via Library Manager: Arduino IDE → Sketch → Include Library → Manage Libraries → Search MFRC522 → Install

License This project is licensed under the MIT License - see the LICENSE file for details.

Author Developed by [MADAN R]