/*
 * MFRC522 - Library to use ARDUINO RFID MODULE KIT 13.56 MHZ WITH TAGS SPI W AND R BY COOQROBOT.
 * The library file MFRC522.h has a wealth of useful info. Please read it.
 * The functions are documented in MFRC522.cpp.
 *
 * Based on code Dr.Leong   ( WWW.B2CQSHOP.COM )
 * Created by Miguel Balboa (circuitito.com), Jan, 2012.
 * Rewritten by Søren Thing Andersen (access.thing.dk), fall of 2013 (Translation to English, refactored, comments, anti collision, cascade levels.)
 * Extended by Tom Clement with functionality to write to sector 0 of UID changeable Mifare cards.
 * 
 * Released into the public domain.
 *
 * This sample shows how to fix a UID changeable MIFARE cards that have a corrupted sector 0.
 * 
 ----------------------------------------------------------------------------- empty_skull 
 
 - Aggiunti pin per arduino Mega
 - Scritto semplice codice per la scrittura e lettura 
 
 - add pin configuration for arduino mega
 - write simple read/write Code for new entry user
 
 http://mac86project.altervista.org/
 
 ----------------------------------------------------------------------------- Nicola Coppola
 * Typical pin layout used:
 * -----------------------------------------------------------------------------------------
 *             MFRC522      Arduino       Arduino   Arduino    Arduino          Arduino
 *             Reader/PCD   Uno           Mega      Nano v3    Leonardo/Micro   Pro Micro
 * Signal      Pin          Pin           Pin       Pin        Pin              Pin
 * -----------------------------------------------------------------------------------------
 * RST/Reset   RST          9             5         D9         RESET/ICSP-5     RST
 * SPI SS      SDA(SS)      10            53        D10        10               10
 * SPI MOSI    MOSI         11 / ICSP-4   51        D11        ICSP-4           16
 * SPI MISO    MISO         12 / ICSP-1   50        D12        ICSP-1           14
 * SPI SCK     SCK          13 / ICSP-3   52        D13        ICSP-3           15
 *
 * The reader can be found on eBay for around 5 dollars. Search for "mf-rc522" on ebay.com. 
 */

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

#define SS_PIN 10
#define RST_PIN 9

MFRC522 mfrc522(SS_PIN, RST_PIN);        // Create MFRC522 instance.
MFRC522::MIFARE_Key key;

void setup() {
        Serial.begin(9600);        // Initialize serial communications with the PC
        while (!Serial);           // Do nothing if no serial port is opened (added for Arduinos based on ATMEGA32U4)
        SPI.begin();               // Init SPI bus
        mfrc522.PCD_Init();        // Init MFRC522 card
        Serial.println(F("Warning: this example clears your mifare UID, use with care!"));
        
        // Prepare key - all keys are set to FFFFFFFFFFFFh at chip delivery from the factory.
        for (byte i = 0; i < 6; i++) {
                key.keyByte[i] = 0xFF;
        }
}

void loop() {
    if ( mfrc522.MIFARE_UnbrickUidSector(false) ) {
      Serial.println(F("Cleared sector 0, set UID to 1234. Card should be responsive again now."));
    }
    delay(1000);
}