#define INCREASE_BUTTON_PIN 8

const int numbers[10] = {
  0x40,
  0x79,
  0x24,
  0x30,
  0x19,
  0x12,
  0x02,
  0x78,
  0x00,
  0x10
};

void setup() {
  DDRD = 0xFF;
  PORTD = 0xFF;
  
  DDRC = 0x0F;
  PORTC = 0x0F;

  pinMode(INCREASE_BUTTON_PIN, INPUT);

}

int currentPort = 1;
int dig4counter = 0;
int dig3counter = 0;
int dig2counter = 0;
int dig1counter = 0;


void loop() {
  PORTC = 1;
  setDigit(1, dig1counter);

  PORTC = 2;
  setDigit(2, dig2counter);

  PORTC = 4;
  setDigit(4, dig3counter);

  PORTC = 8;
  setDigit(8, dig4counter);
  
  int increasePin = digitalRead(INCREASE_BUTTON_PIN);
  if (increasePin){

    if (dig2counter == 9 && dig3counter == 9 && dig4counter == 9){
      dig1counter  = (dig1counter + 1 ) % 10;
    }

    if (dig3counter == 9 && dig4counter == 9){
      dig2counter = (dig2counter + 1 ) % 10;
    }

    if (dig4counter == 9){
      dig3counter = (dig3counter + 1 ) % 10;
    }

    dig4counter = (dig4counter + 1 ) % 10;
    
    delay(100);
  }
  
}

void setDigit(int index, int digit){
  PORTD = 0xFF; //reset with HIGH

  PORTD = numbers[digit];
  PORTD = 0xFF; //reset with HIGH
}