RFID Wiegand e sd card log

Boa tarde pessoal,

Estou com montando um projeto com RFID wiegand com o log no SD card, porém estou com um problema na hora de realizar a comparação do ID gravado com o lido.

A programação é uma adaptação do programa criado pelo Daniel da pagemac.

Se alguém tiver uma idéia para ajudar.

/*
 * HID RFID Reader Wiegand Interface for Arduino Uno
 * Written by Daniel Smith, 2012.01.30
 * www.pagemac.com
 *
 * This program will decode the wiegand data from a HID RFID Reader (or, theoretically,
 * any other device that outputs weigand data).
 * The Wiegand interface has two data lines, DATA0 and DATA1.  These lines are normall held
 * high at 5V.  When a 0 is sent, DATA0 drops to 0V for a few us.  When a 1 is sent, DATA1 drops
 * to 0V for a few us.  There is usually a few ms between the pulses.
 *
 * Your reader should have at least 4 connections (some readers have more).  Connect the Red wire 
 * to 5V.  Connect the black to ground.  Connect the green wire (DATA0) to Digital Pin 2 (INT0).  
 * Connect the white wire (DATA1) to Digital Pin 3 (INT1).  That's it!
 *
 * Operation is simple - each of the data lines are connected to hardware interrupt lines.  When
 * one drops low, an interrupt routine is called and some bits are flipped.  After some time of
 * of not receiving any bits, the Arduino will decode the data.  I've only added the 26 bit and
 * 35 bit formats, but you can easily add more.
 
*/
#include <SPI.h>
#include <SD.h>

 File myFile;
 
#define MAX_BITS 100                 // max number of bits 
#define WEIGAND_WAIT_TIME  3000      // time to wait for another weigand pulse.  
 
unsigned char databits[MAX_BITS];    // stores all of the data bits
unsigned char bitCount;              // number of bits currently captured
unsigned char flagDone;              // goes low when data is currently being captured
unsigned int weigand_counter;        // countdown until we assume there are no more bits
 
unsigned long facilityCode=0;        // decoded facility code
unsigned long cardCode=0;            // decoded card code


/////////////////////////Setup //////////////////////////////////// 
void setup()
{
  pinMode(13, OUTPUT);  // LED
  pinMode(2, INPUT);     // DATA0 (INT0)
  pinMode(3, INPUT);     // DATA1 (INT1)
 
  Serial.begin(9600);
  Serial.println("RFID Readers");
 
  // binds the ISR functions to the falling edge of INTO and INT1
  attachInterrupt(0, ISR_INT0, FALLING);  
  attachInterrupt(1, ISR_INT1, FALLING);
 
 
  weigand_counter = WEIGAND_WAIT_TIME;

    Serial.print("Iniciando o SD card...");

  if (!SD.begin(4)) {
    Serial.println("Falha na inicializacao!");
    return;
  }
  Serial.println("Inicializado.");
}
//////////////////////////Loop principal //////////////////////////////// 
void loop()
{
 le_id();
}

//////////////////////////////Mostra o ID e o código de checagem lidos/////////////// 
void printBits()
{
      // I really hope you can figure out what this function does
      Serial.print("FC = ");
      Serial.print(facilityCode);
      Serial.print(", CC = ");
      Serial.println(cardCode); 
}

///////////////////////////////Grava o ID lido no SD card///////////////////////
void grava_sd()
{

  
       myFile = SD.open("data.csv", FILE_WRITE);
       if (myFile) {
  
    Serial.print("Writing to data.csv...");   
    myFile.println(cardCode);
    // close the file:
    myFile.close();
    Serial.println("Gravado");
  } else {
    // if the file didn't open, print an error:
    Serial.println("error opening data.csv");
  }
}
///////////////Le todos os ids gravados no SD card /////////////////////////////
void le_sd(){
myFile = SD.open("data.csv");
  if (myFile) {
    Serial.println("data.csv:");

    // read from the file until there's nothing else in it:
    while (myFile.available()) {

      
      Serial.write(myFile.read());
    }
    // close the file:
    myFile.close();
  } else {
    // if the file didn't open, print an error:
    Serial.println("error opening data.csv");
  }
  }

/////////////////////////Le ID do receptor ///////////////////////////////
void le_id(){
  
 // This waits to make sure that there have been no more data pulses before processing data
  if (!flagDone) {
    if (--weigand_counter == 0)
      flagDone = 1;  
  }
 
  // if we have bits and we the weigand counter went out
  if (bitCount > 0 && flagDone) {
    unsigned char i;
 
    Serial.print("Read ");
    Serial.print(bitCount);
    Serial.print(" bits. ");
 
    // we will decode the bits differently depending on how many bits we have
    // see www.pagemac.com/azure/data_formats.php for mor info
    
    if (bitCount == 26)
    {
      // standard 26 bit format
      // facility code = bits 2 to 9
      for (i=1; i<9; i++)
      {
         facilityCode <<=1;
         facilityCode |= databits[i];
      }
 
      // card code = bits 10 to 23
      for (i=9; i<25; i++)
      {
         cardCode <<=1;
         cardCode |= databits[i];
      }
 
      printBits();  
    
    }
    else {
      // you can add other formats if you want!
     Serial.println("Unable to decode."); 
    }
 
     // cleanup and get ready for the next card
     bitCount = 0;
     facilityCode = 0;
     cardCode = 0;
     for (i=0; i<MAX_BITS; i++) 
     {
       databits[i] = 0;
     }
  }
}
///////////////////////////////Le a interrupção na porta 2//////////////////
// interrupt that happens when INTO goes low (0 bit)
void ISR_INT0()
{
  //Serial.print("0");   // uncomment this line to display raw binary
  bitCount++;
  flagDone = 0;
  weigand_counter = WEIGAND_WAIT_TIME;  
 
}
////////////////////////////Le a interrupção na porta 3///////////////////// 
// interrupt that happens when INT1 goes low (1 bit)
void ISR_INT1()
{
  //Serial.print("1");   // uncomment this line to display raw binary
  databits[bitCount] = 1;
  bitCount++;
  flagDone = 0;
  weigand_counter = WEIGAND_WAIT_TIME;  
}