// Define pins for buzzer and LEDs
#define BUZZER_PIN 5
#define LED_PIN_1 6
#define LED_PIN_2 9
#define LED_PIN_3 10

// Define variables for menu options
bool isBuzzerOn = false;
int ledBlinkSpeed = 500; // default blinking speed of LED
bool isLedBrightnessHigh = false; // default brightness of LED

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  while (!Serial) {
    ; // Wait for the serial connection to be established
  }

  // Print the initial menu
  Serial.println("Select a menu option:");
  Serial.println("1: Toggle the buzzer");
  Serial.println("2: Toggle LED 1");
  Serial.println("3: Increase speed of LED 2");
  Serial.println("4: Decrease speed of LED 2");
  Serial.println("5: Toggle brightness of LED 3");

  // Set pin modes
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LED_PIN_1, OUTPUT);
  pinMode(LED_PIN_2, OUTPUT);
  pinMode(LED_PIN_3, OUTPUT);
}

void loop() {
  // Check if there is incoming data from serial
  if (Serial.available() > 0) {
    // Read the incoming byte
    char menuOption = Serial.read();

    // Execute the corresponding menu option
    switch (menuOption) {
      case '1':
        // Toggle the buzzer on and off
        isBuzzerOn = !isBuzzerOn;
        digitalWrite(BUZZER_PIN, isBuzzerOn);
        break;
      case '2':
        // Toggle the first LED on and off
        digitalWrite(LED_PIN_1, !digitalRead(LED_PIN_1));
        break;
      case '3':
        // Increase the speed of the second LED's blinking
        ledBlinkSpeed -= 50;
        if (ledBlinkSpeed < 50) {
          ledBlinkSpeed = 50; // set minimum blinking speed
        }
        break;
      case '4':
        // Decrease the speed of the second LED's blinking
        ledBlinkSpeed += 50;
        if (ledBlinkSpeed > 1000) {
          ledBlinkSpeed = 1000; // set maximum blinking speed
        }
        break;
      case '5':
        // Toggle the brightness of the third LED between high and low
        isLedBrightnessHigh = !isLedBrightnessHigh;
        if (isLedBrightnessHigh) {
          analogWrite(LED_PIN_3, 255); // set high brightness
        } else {
          analogWrite(LED_PIN_3, 128); // set low brightness
        }
        break;
      default:
        // Invalid menu option, do nothing
        break;
    }
  }

  // Blink the second LED with the current blinking speed
  static unsigned long previousMillis = 0;
  if (millis() - previousMillis >= ledBlinkSpeed) {
    previousMillis = millis();
    digitalWrite(LED_PIN_2, !digitalRead(LED_PIN_2));
  }
}