framework-arduinoteensy-cxx20/libraries/MFRC522/examples/FixBrickedUID/FixBrickedUID.ino

/*
 * --------------------------------------------------------------------------------------------------------------------
 * Example sketch/program to fix a broken UID changeable MIFARE cards.
 * --------------------------------------------------------------------------------------------------------------------
 * This is a MFRC522 library example; for further details and other examples see: https://github.com/miguelbalboa/rfid
 * 
 * This sample shows how to fix a broken UID changeable MIFARE cards that have a corrupted sector 0.
 * 
 * @author Tom Clement
 * @license Released into the public domain.
 * 
 * Typical pin layout used:
 * -----------------------------------------------------------------------------------------
 *             MFRC522      Arduino       Arduino   Arduino    Arduino          Arduino
 *             Reader/PCD   Uno/101       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
 */

#include <SPI.h>
#include <MFRC522.h>
#include <MFRC522Hack.h>

constexpr uint8_t RST_PIN = 9;     // Configurable, see typical pin layout above
constexpr uint8_t SS_PIN = 10;     // Configurable, see typical pin layout above

MFRC522 mfrc522(SS_PIN, RST_PIN);  // Create MFRC522 instance.
MFRC522Hack mfrc522Hack(&mfrc522);  // Create MFRC522Hack 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 ( mfrc522Hack.MIFARE_UnbrickUidSector(false) ) {
    Serial.println(F("Cleared sector 0, set UID to 1234. Card should be responsive again now."));
  }
  delay(1000);
}