Tag_Write_Pattern.ino

/*
   Write personal data of a MIFARE RFID card using a RFID-RC522 reader
   Uses MFRC522 - Library to use ARDUINO RFID MODULE KIT 13.56 MHZ WITH TAGS SPI W AND R BY COOQROBOT.
   -----------------------------------------------------------------------------------------
               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 (7)            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

   Hardware required:
   Arduino
   PCD (Proximity Coupling Device): NXP MFRC522 Contactless Reader IC
   PICC (Proximity Integrated Circuit Card): A card or tag using the ISO 14443A interface, eg Mifare or NTAG203.
   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 RST_PIN         49           // Configurable, see typical pin layout above
#define SS_PIN          53          // Configurable, see typical pin layout above

#define PATTERN_ID      6
#define BLOCK           1

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

void setup() {
  Serial.begin(9600);        // Initialize serial communications with the PC
  SPI.begin();               // Init SPI bus
  mfrc522.PCD_Init();        // Init MFRC522 card
  Serial.println(F("Write TAG Pattern ID"));
}

void loop() {
  MFRC522::StatusCode status;

  // 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;
  }

  // Look for new cards
  if ( ! mfrc522.PICC_IsNewCardPresent()) {
    return;
  }

  // Select one of the cards
  if ( ! mfrc522.PICC_ReadCardSerial()) {
    return;
  }

  Serial.print(F("Card UID(HEX):"));    //Dump HEX UID
  for (byte i = 0; i < mfrc522.uid.size; i++) {
    Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
    Serial.print(mfrc522.uid.uidByte[i], HEX);
  }

  Serial.print(F(" PICC type: "));   // Dump PICC type
  MFRC522::PICC_Type piccType = mfrc522.PICC_GetType(mfrc522.uid.sak);
  Serial.println(mfrc522.PICC_GetTypeName(piccType));

  byte readbackblock[18];//This array is used for reading out a block. The MIFARE_Read method requires a buffer that is at least 18 bytes to hold the 16 bytes of a block.
  readBlock(BLOCK, readbackblock);//read the block back
  Serial.print("read block: ");
  for (int j = 0 ; j < 16 ; j++) //print the block contents
  {
    Serial.print (readbackblock[j]);//Serial.write() transmits the ASCII numbers as human readable characters to serial monitor
    Serial.print (" ");
  }
  Serial.println("");

  byte blockcontent[16];
  for (int i = 0; i<16; i++){
    blockcontent[i]=0;
  }
  blockcontent[0]= PATTERN_ID;
  writeBlock(BLOCK, blockcontent);//the blockcontent array is written into the card block

  Serial.println(" ");

  readBlock(BLOCK, readbackblock);//read the block back
  Serial.print("read block: ");
  for (int j = 0 ; j < 16 ; j++) //print the block contents
  {
    Serial.print (readbackblock[j]);//Serial.write() transmits the ASCII numbers as human readable characters to serial monitor
    Serial.print (" ");
  }
  
  Serial.println("");

  mfrc522.PICC_DumpToSerial(&(mfrc522.uid));

  
  mfrc522.PICC_HaltA(); // Halt PICC
  mfrc522.PCD_StopCrypto1();  // Stop encryption on PCD

}