Added RFID reader code which tells ID

Arduino/rfid/rfid.ino

@@ -0,0 +1,55 @@
+/*
+ Voltaat learn (http://learn.voltaat.com)
+ Link for full tutorial:
+ RFID reader library:
+
+ Tutorial: Getting card ID using RFID reader
+
+ It's important to be aware that the RFID reader module runs on 3.3V, not 5V.
+ Therefore, it should be connected to the 3.3V pin.
+
+ Connections from the RFID reader to the Arduino:
+ • RFID 3.3V pin → Arduino VCC (3.3V) pin
+ • RFID RST pin → Arduino pin 9
+ • RFID GND pin → Arduino GND pin
+ • RFID IRQ pin → unconnected
+ • RFID MISO pin → Arduino pin 12
+ • RFID MOSI pin → Arduino pin 11
+ • RFID SCK pin → Arduino pin 13
+ • RFID SDA pin → Arduino pin 10
+ 
+*/
+
+#include "MFRC522.h"   // Include the MFRC522 RFID library
+
+#define SS_PIN 10       // Define the SS pin for the RFID reader
+#define RST_PIN 9       // Define the RST pin for the RFID reader
+
+MFRC522 rfid(SS_PIN, RST_PIN);  // Create an MFRC522 instance
+
+void setup() {
+ Serial.begin(9600);   // Initialize serial communication
+ SPI.begin();          // Initialize SPI
+ rfid.PCD_Init();      // Initialize RFID reader
+ Serial.println("RFID Reader Initialized");
+ Serial.println("Please approximate your card to the RFID reader...");
+}
+
+void loop() {
+ // Check for new RFID cards
+ if (rfid.PICC_IsNewCardPresent() && rfid.PICC_ReadCardSerial()) {
+   // Get the card UID
+   String cardUID = "";
+   for (byte i = 0; i < rfid.uid.size; i++) {
+     cardUID += String(rfid.uid.uidByte[i], HEX);
+     if (i < rfid.uid.size - 1) {  // Add space between bytes except for the last byte
+       cardUID += " ";
+     }
+   }
+
+   Serial.print("Card ID: ");
+   Serial.println(cardUID);
+   rfid.PICC_HaltA();  // Halt the card
+   rfid.PCD_StopCrypto1(); // Stop encryption on the card
+ }
+}