#define BUTTON1_PIN 4
#define BUTTON2_PIN 2
#define LED0_PIN 8
#define LED1_PIN 9
#define LED2_PIN 10
#define LED3_PIN 11
volatile byte counter = 0;
void resetCounter() {
  counter = 0;
}
void setup() {
  pinMode(BUTTON1_PIN, INPUT_PULLUP);
  pinMode(BUTTON2_PIN, INPUT_PULLUP);
  pinMode(LED0_PIN, OUTPUT);
  pinMode(LED1_PIN, OUTPUT);
  pinMode(LED2_PIN, OUTPUT);
  pinMode(LED3_PIN, OUTPUT);
  attachInterrupt(
    digitalPinToInterrupt(BUTTON2_PIN),
    resetCounter,
    RISING);
}
void loop() {
  static bool buttonPrevious = 0;
  if(!digitalRead(BUTTON1_PIN) == 1 && buttonPrevious == 0) {
    delay(100);
    counter++;
    if(counter > 15) counter = 0;
    buttonPrevious = 1;
  } else if (!digitalRead(BUTTON1_PIN) == 0) {
    delay(100);
    buttonPrevious = 0;
  }
  digitalWrite(LED0_PIN, counter%2);
  digitalWrite(LED1_PIN, counter/2%2);
  digitalWrite(LED2_PIN, counter/4%2);
  digitalWrite(LED3_PIN, counter/8%2);
}