problema con rfid

unire i codici non e' niente, il problema e' capire

codici uniti

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

#define SAD 10
#define RST 5

MFRC522 nfc(SAD, RST);

Servo myservo;  // create servo object to control a servo
// a maximum of eight servo objects can be created
int pos = 0;    // variable to store the servo position

void setup() {
  SPI.begin();
  // Read a fast as possible. There is a limit for how long we are
  // allowed to read from the tags.

  myservo.attach(9);  // attaches the servo on pin 9 to the servo object

  Serial.begin(115200);

  Serial.println("Looking for MFRC522.");
  nfc.begin();

  // Get the firmware version of the RFID chip
  byte version = nfc.getFirmwareVersion();
  if (! version) {
    Serial.print("Didn't find MFRC522 board.");
    while(1); //halt
  }

  Serial.print("Found chip MFRC522 ");
  Serial.print("Firmware ver. 0x");
  Serial.print(version, HEX);
  Serial.println(".");
}

byte keyA[6] = {
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, };
byte keyB[6] = {
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, };

void loop() {
  byte status;
  byte data[MAX_LEN];
  byte serial[5];
  int i, j, pos;

  // Send a general request out into the aether. If there is a tag in
  // the area it will respond and the status will be MI_OK.
  status = nfc.requestTag(MF1_REQIDL, data);

  if (status == MI_OK) {
    Serial.println("Tag detected.");
    Serial.print("Type: ");
    Serial.print(data[0], HEX);
    Serial.print(", ");
    Serial.println(data[1], HEX);
    
    //**************************************************************
    Gira_servo(); // gira servo quando si passa una carta 
    //**************************************************************
    
    // calculate the anti-collision value for the currently detected
    // tag and write the serial into the data array.
    status = nfc.antiCollision(data);
    memcpy(serial, data, 5);

    Serial.println("The serial nb of the tag is:");
    for (i = 0; i < 3; i++) {
      Serial.print(serial[i], HEX);
      Serial.print(", ");
    }
    Serial.println(serial[3], HEX);

    // Select the tag that we want to talk to. If we don't do this the
    // chip does not know which tag it should talk if there should be
    // any other tags in the area..
    nfc.selectTag(serial);

    // Assuming that there are only 64 blocks of memory in this chip.
    for (i = 0; i < 64; i++) {
      // Try to authenticate each block first with the A key.
      status = nfc.authenticate(MF1_AUTHENT1A, i, keyA, serial);
      if (status == MI_OK) {
        Serial.print("Authenticated block nb. 0x");
        Serial.print(i, HEX);
        Serial.println(" with key A.");
        // Reading block i from the tag into data.
        status = nfc.readFromTag(i, data);
        if (status == MI_OK) {
          // If there was no error when reading; print all the hex
          // values in the data.
          for (j = 0; j < 15; j++) {
            Serial.print(data[j], HEX);
            Serial.print(", ");
          }
          Serial.println(data[15], HEX);
          
          //**********************************************************************
          Gira_servo(); // carta A riconosciuta, gira il servo
          //**********************************************************************
          
        } 
        else {
          Serial.println("Read failed.");
        }
      } 
      else {
        // If we could not authenticate with the A key, we will try
        // the B key.
        status = nfc.authenticate(MF1_AUTHENT1B, i, keyB, serial);
        if (status == MI_OK) {
          Serial.print("Authenticated block nb. 0x");
          Serial.print(i, HEX);
          Serial.println(" with key B.");
          status = nfc.readFromTag(i, data);
          if (status == MI_OK) {
            for (j = 0; j < 15; j++) {
              Serial.print(data[j], HEX);
              Serial.print(", ");
            }
            Serial.println(data[15], HEX);
          } 
          else {
            Serial.println("Read failed.");
          }
        } 
        else {
          Serial.print("Access denied at block nb. 0x");
          Serial.println(i, HEX);
        }
      }
    }

    // Stop the tag and get ready for reading a new tag.
    nfc.haltTag();
  }
  delay(2000);
}

void Gira_servo()
{
  for(pos = 0; pos < 180; pos += 1)  // goes from 0 degrees to 180 degrees
  {                                  // in steps of 1 degree
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                       // waits 15ms for the servo to reach the position
  }
  for(pos = 180; pos>=1; pos-=1)     // goes from 180 degrees to 0 degrees
  {                                
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                       // waits 15ms for the servo to reach the position
  }
}