#define ECHO_PIN 3 
#define TRIG_PIN 2 
#define pinBuzzer 5 
#define pinLED 6 

#include <Servo.h>

Servo myservo;
int rotasi = 90;
int interval = 0;

float readDistanceCM(){
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0,034/2;
}

void soundBuzzer (){
  if(interval < 500){
    tone(pinBuzzer, 250);
    digitalWrite(pinLED, HIGH);
  }else
  if(interval < 500){
    tone(pinBuzzer, 100,800);
    digitalWrite(pinLED, LOW);
  }
}

void setup(){
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  Serial.begin(115200);
  pinMode(pinBuzzer, OUTPUT);
  pinMode(pinLED, OUTPUT);
  myservo.attach(9);
  myservo.write(90);

}

void loop(){
  tutupPalang();
  interval +=100;
  if(interval>100) interval = 0;
}

void tutupPalang(){
  float jarak = readDistanceCM();
  if(jarak > 0 && jarak < 100){
    soundBuzzer();
    tutup();
  }else{
    buka();
    noTone(pinBuzzer);
    digitalWrite(pinLED, LOW);
  }
}

void tutup(){
  if(rotasi <=90){
    myservo.write(rotasi);
    delay(1000);
    rotasi--;
  }
  if(rotasi <=0) rotasi = 0;
}

void buka(){
  if(rotasi <= 90){
    myservo.write(rotasi);
    delay(1000);
    rotasi+=4;
  }
  if(rotasi >=90) rotasi = 90;
}