RFID

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

#define RST_PIN 9
#define SS_PIN  10

MFRC522 mfrc522(SS_PIN, RST_PIN);

void setup() {
    serial.begin(9600);
    while (!Serial);
    SPI.begin();
    mfrc522.PCD_Init();
    delay(4);
    mfrc522.PCD_DumpVersionToSerial();
    Serial.println(F("Scan PICC to see UID, SAK, type, and data blocks..."));
}

void loop() {

    if ( ! mfrc522.PICC_IsNewCardPresent() ) {
        return;
    }

    if ( ! mfrc522.PICC_ReadCardSerial() ) {
        return;
    }
String uid = "";
    for (byte i = 0; i < mfrc522.uid.size; i++) {
        uid.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
        uid.concat(String(mfrc522.uid.uidByte[i], HEX));
    }
uid.toUpperCase();
Serial.println(uid);
delay (3000);

    if (uid.substring(1) == "F5 7E 7E 63")      //Replace this with the HEX value that your card has
    {
     Serial.println("ID Accepted");
    }
    else
    {
     Serial.println("ID Denied");
    }

}