#include <Servo.h>

// Define pins
const int trigPin = 9;
const int echoPin = 10;
const int buzzerPin = 8;
Servo myServo;

void setup() {
  // Initialize the serial communication
  Serial.begin(9600);
  
  // Initialize the HC-SR04 sensor pins
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  
  // Initialize the buzzer pin
  pinMode(buzzerPin, OUTPUT);
  
  // Attach the servo to pin 3
  myServo.attach(3);
}

void loop() {
  for (int angle = 0; angle <= 180; angle += 10) {
    myServo.write(angle);
    delay(500);
    float distance = measureDistance();
    Serial.print("Angle: ");
    Serial.print(angle);
    Serial.print(" Distance: ");
    Serial.print(distance);
    Serial.println(" cm");
    if (distance < 20) {
      soundBuzzer(100);
    }
    delay(100);
  }

  for (int angle = 180; angle >= 0; angle -= 10) {
    myServo.write(angle);
    delay(500);
    float distance = measureDistance();
    Serial.print("Angle: ");
    Serial.print(angle);
    Serial.print(" Distance: ");
    Serial.print(distance);
    Serial.println(" cm");
    if (distance < 20) {
      soundBuzzer(100);
    }
    delay(100);
  }
}

float measureDistance() {
  // Clear the trigger pin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  
  // Set the trigger pin HIGH for 10 microseconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  // Read the echo pin
  long duration = pulseIn(echoPin, HIGH);
  
  // Calculate the distance
  float distance = (duration * 0.034) / 2;
  
  return distance;
}

void soundBuzzer(int durationMs) {
  digitalWrite(buzzerPin, HIGH);
  delay(durationMs);
  digitalWrite(buzzerPin, LOW);
}