int violet_LED = 15;
int yellow_LED = 21;
int red_LED = 23;
int blue_LED = 22;
int switchPin = 2;

void setup() {
  pinMode(violet_LED, OUTPUT);
  pinMode(yellow_LED, OUTPUT);
  pinMode(red_LED, OUTPUT);
  pinMode(blue_LED, OUTPUT);
  pinMode(switchPin, INPUT);

  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
}

void loop() {
  int switchState = digitalRead(switchPin);

  if (switchState == HIGH) {
    digitalWrite(violet_LED, HIGH);
    digitalWrite(yellow_LED, LOW);
    digitalWrite(red_LED, LOW);
    digitalWrite(blue_LED, LOW);
    delay(500);

    digitalWrite(violet_LED, LOW);
    digitalWrite(yellow_LED, HIGH);
    digitalWrite(red_LED, LOW);
    digitalWrite(blue_LED, LOW);
    delay(500);

    digitalWrite(violet_LED, LOW);
    digitalWrite(yellow_LED, LOW);
    digitalWrite(red_LED, HIGH);
    digitalWrite(blue_LED, LOW);
    delay(500);

    digitalWrite(violet_LED, LOW);
    digitalWrite(yellow_LED, LOW);
    digitalWrite(red_LED, LOW);
    digitalWrite(blue_LED, HIGH);
    delay(500);
  } else {
    digitalWrite(violet_LED, LOW);
    digitalWrite(yellow_LED, LOW);
    digitalWrite(red_LED, LOW);
    digitalWrite(blue_LED, LOW);
  }
}