const byte LEDS[] = {13,12,11,10,9,8,7,6};
const byte SIZE = 8;
const byte CARD[] = {1,2,3,4};
const byte BASE[] = {1,2,4,8,16,32,64, 128};
const byte IN_DATA[] = {3,5,2,1,7};
const byte IN_SIZE = 5;
short it = 0;
int sum = 0;

void leds_on( byte );
void leds_off( void );
void test_numbers( int );

void setup() {

  /* Serial setup for debugging */
  Serial.begin(9600);

  /* Set the 8 led ports as output */
  for (byte i = 0; i < SIZE; i++) {
    pinMode(LEDS[i], OUTPUT);
  }

  /* Setup button pin as input */
  pinMode(2, INPUT);
}

void loop() {

  /* If end of punched card then show sum and exit */
  if (it >= IN_SIZE) {
    leds_on(sum);
    delay(3000);
    leds_off();
    exit(0);
  }

  /* If button pressed show next number in punched card */
  if (digitalRead(2)) {
    leds_on(IN_DATA[it]);
    sum += IN_DATA[it];
    it++;
    delay(1000);
    leds_off();
    delay(1000);
  }
}

/* Shows a number on the leds */
void leds_on(byte num) {

  /* From higher led until lower led*/
  for (signed char i = SIZE-1; i >= 0; i--) {

    /* Turn on led if num is higher than led base */
    if (num >= BASE[i]) {
      digitalWrite(LEDS[i], HIGH);

      /* Subtract led base to num to reduce it*/
      num -= BASE[i];
    }
  }
}

void leds_off( void ) {
  for (byte i=0; i < SIZE; i++) {
    digitalWrite(LEDS[i], LOW);
  }
}

/* Test numbers from 0 to 255*/
void test_numbers(int time) {
  for (byte i = 0; i < 256; i++) {
    leds_on(i);
    delay(time);
    leds_off();
    delay(time);
  }
}