int timer = 150;           // The higher the number, the slower the timing.
int buzzerPin = 9;         // Pin for the buzzer
int buttonPin = 10;        // Pin for the button
int buttonState = 0;       // Variable to store the button state

void setup() {
  // Use a for loop to initialize each pin as an output:
  for (int thisPin = 2; thisPin < 8; thisPin++) {
    pinMode(thisPin, OUTPUT);
  }

  pinMode(buzzerPin, OUTPUT);   // Set buzzer pin as OUTPUT
  pinMode(buttonPin, INPUT);    // Set button pin as INPUT
}

void loop() {
  // Read the state of the button
  buttonState = digitalRead(buttonPin);

  // Check if the button is pressed to activate the sequence
  if (buttonState == HIGH) {
    // Loop from the lowest pin to the highest:
    for (int thisPin = 2; thisPin < 8; thisPin++) {
      // Turn the pin on:
      digitalWrite(thisPin, HIGH);
      // Activate the buzzer
      digitalWrite(buzzerPin, HIGH);
      delay(timer);
      // Turn the pin off:
      digitalWrite(thisPin, LOW);
      // Deactivate the buzzer
      digitalWrite(buzzerPin, LOW);
    }

    // Loop from the highest pin to the lowest:
    for (int thisPin = 7; thisPin >= 2; thisPin--) {
      // Turn the pin on:
      digitalWrite(thisPin, HIGH);
      // Activate the buzzer
      digitalWrite(buzzerPin, HIGH);
      delay(timer);
      // Turn the pin off:
      digitalWrite(thisPin, LOW);
      // Deactivate the buzzer
      digitalWrite(buzzerPin, LOW);
    }
  }
}