// https://forum.arduino.cc/t/cant-call-on-loops-using-serial-monitor/1055601
// https://wokwi.com/projects/348775516561474130

# define buttonPin  7

void setup() {
  Serial.begin(115200);
  Serial.println("Hello W0rld!");

  pinMode(buttonPin, INPUT_PULLUP);
}

int sequence;

void loop() {
  if (digitalRead(buttonPin) == LOW) {
    delay(100);
    if (digitalRead(buttonPin) == LOW) {
      if (sequence == 8) {
        sequence = 0;
      }
      sequence++;
      Serial.println(sequence);
    }
  }
}