#define COUNT 7

const int sevseg_a = 2;
byte num_segments[16] = { 0b10100000,
                          0b11111001,
                          0b11000100,
                          0b11010000,
                          0b10011001,
                          0b10010010,
                          0b10000010,
                          0b11111000,
                          0b10000000,
                          0b10010000,
                          0b10001000,
                          0b10000011,
                          0b10100110,
                          0b11000001,
                          0b10000110,
                          0b10001110 };
boolean segment;
int mask = 0;
int num = 0;

int lastButton = LOW;
int curButton = LOW;
const int button = 12;

void setup() {

  for (int i = sevseg_a; i < COUNT + sevseg_a; i++) {

    pinMode(i, OUTPUT);
    digitalWrite(i, HIGH);
  }

  pinMode(button, INPUT);
  digitalWrite(button, HIGH);
}

int debounce (int last) {

  int current = digitalRead(button);

  if (last != current) {

    delay(10);
    current = digitalRead(button);
  }

  return current;
}

void loop() {

  curButton = debounce(lastButton);

  if (lastButton == HIGH && curButton == LOW) {

    mask = num_segments[num];

    for (int i = 0; i < COUNT; i++) {

      segment = bitRead(mask, i);
      digitalWrite(i + sevseg_a, segment);
    }

    num++;
    
    if (num > 15) {

      num = 0;
    }
  }

  lastButton = curButton;
}