/* mifare ultralight example (25-02-2018)
 *
 *   RFID-RC522 (SPI connexion)
 *   
 *   CARD RC522      Arduino (UNO)
 *     SDA1  -----------  10 (Configurable, see SS_PIN constant)
 *     SDA2  -----------  0 (Configurable, see SS_PIN constant)
 *     SCK  -----------  13
 *     MOSI -----------  11
 *     MISO -----------  12
 *     IRQ  ----------- 
 *     GND  -----------  GND
 *     RST  -----------  9 (onfigurable, see RST_PIN constant)
 *     3.3V ----------- 3.3V
 *     
 */

  #include <SPI.h>
  #include <MFRC522.h>
 
 
  #define SS_1_PIN          10
  #define SS_2_PIN          8
  #define RST_PIN         9

  constexpr uint8_t NR_OF_READERS = 1;
  byte ssPins[] = {SS_1_PIN, SS_2_PIN};
  
  MFRC522 mfrc522[NR_OF_READERS]; 
  MFRC522::StatusCode status; //variable to get card status
 
  byte buffer[18];  //data transfer buffer (16+2 bytes data+CRC)
  byte size = sizeof(buffer);

  uint8_t pageAddr = 0x06;  //In this example we will write/read 16 bytes (page 6,7,8 and 9).
                            //Ultraligth mem = 16 pages. 4 bytes per page. 
                            //Pages 0 to 4 are for special functions.           
 
void setup() {
  Serial.begin(9600); // Initialize serial communications with the PC
  SPI.begin(); // Init SPI bus
  
  for (uint8_t reader = 0; reader < NR_OF_READERS; reader++) {
    mfrc522[reader].PCD_Init(ssPins[reader], RST_PIN); // Init each MFRC522 card
    Serial.print(F("Reader "));
    Serial.print(reader);
    Serial.print(F(": "));
    mfrc522[reader].PCD_DumpVersionToSerial();
  }
  
  Serial.println(F("Sketch has been started!"));
 // memcpy(buffer,"Bqq",16);
  //String mystring ="bcc";
 // mystring.toCharArray(buffer, 16);
  
}

String mystring;
bool set = true;

void loop() {
  if(set){
  Serial.println("What should be written");
  while (Serial.available()==0) {             //Wait for user input
  
  }
  mystring = Serial.readString();  
  mystring.toCharArray(buffer, 16);
  set = false;
  Serial.println("write   :"+mystring);
  Serial.println("RFID Auflegen");
  }
   
  if ( ! mfrc522[0].PICC_IsNewCardPresent())
    return;

  // Select one of the cards
  if ( ! mfrc522[0].PICC_ReadCardSerial())
    return;

  // Write data ***********************************************
   
 
  for (int i=0; i < 4; i++) {
    //data is writen in blocks of 4 bytes (4 bytes per page)
    status = (MFRC522::StatusCode) mfrc522[0].MIFARE_Ultralight_Write(pageAddr+i, &buffer[i*4], 4);
    if (status != MFRC522::STATUS_OK) {
      Serial.print(F("MIFARE_Read() failed: "));
      Serial.println(mfrc522[0].GetStatusCodeName(status));
      return;
    }
  }
  Serial.println(F("MIFARE_Ultralight_Write() OK "));
  Serial.println();


  // Read data ***************************************************
  Serial.println(F("Reading data ... "));
  //data in 4 block is readed at once.
  status = (MFRC522::StatusCode) mfrc522[0].MIFARE_Read(pageAddr, buffer, &size);
  if (status != MFRC522::STATUS_OK) {
    Serial.print(F("MIFARE_Read() failed: "));
    Serial.println(mfrc522[0].GetStatusCodeName(status));
    return;
  }

  Serial.print(F("Readed data: "));
  //Dump a byte array to Serial
  for (byte i = 0; i < 3; i++) {
    Serial.write(buffer[i]);
  }
  Serial.println();

  mfrc522[0].PICC_HaltA();
  set = true;

}