#include <ESP32Servo.h>

#define TRIG_PIN 23 
#define ECHO_PIN 22 
#define SERVO_PIN 26 
#define LED_PIN 27 
#define DISTANCE_THRESHOLD 50 

Servo servo; 
float duration_us, distance_cm;

void setup() {
  Serial.begin(9600); 
  pinMode(23, OUTPUT); 
  pinMode(22, INPUT); 
  pinMode(13, OUTPUT); 
  servo.attach(14); 
  servo.write(0); 
}

void loop() {
  digitalWrite(23, HIGH);
  delayMicroseconds(10);
  digitalWrite(23, LOW);

  duration_us = pulseIn(22, HIGH);

  distance_cm = 0.017 * duration_us;

  if (distance_cm >= 0 && distance_cm <= 50) {
    servo.write(360);
    digitalWrite(13, LOW);
  } else if (distance_cm > 50 && distance_cm <= 100) {
    servo.write(-360);
    digitalWrite(13, HIGH);
  } else {
    servo.write(0);
    digitalWrite(13, LOW);
  }

  Serial.print("Distance: ");
  Serial.print(distance_cm);
  Serial.println(" cm");

  delay(500);
}