//The number of keys to check for.
static int KEY_NUM = 3;

//Accepted keys.
static long KEYS[] = {
-881179883, //Ben
-881179695, //Helen
-814070751 //Jordan

//-881188651 //Gina
};

volatile long current = 0;
volatile boolean changed = false;

void DATA1() {  
  //Shift bits left; add one
  current = current << 1;
  current += 1;
  changed = true;
  Serial.print(1);
}

void DATA0() {
  //Shift bits left; (add zero)
  current = current << 1;
  changed = true;
  Serial.print(0);
}

void CARD() {
  Serial.println();
}

void check() {
  for (int i = 0; i < KEY_NUM; i++) {
    if (KEYS[i] == current) {
      unlock();
    }
  }
}

void unlock() {
  Serial.println("Match!");
  
  
}

void setup() {
  Serial.begin(9600);
  
  attachInterrupt(0, DATA0, FALLING);  // DATA0 (green) on HID reader, Pin 2 on Arduino
  attachInterrupt(1, DATA1, FALLING);  // DATA1 (white) on HID reader, Pin 3 on Arduino
  delay(10);
}

void loop() {
  delay(100);
  if (changed) {
    check();
    Serial.println();
    Serial.println(current);
  }
  changed = false;
}