#define ECHO_pin 3
#define TRIG_pin 2
#define pinBuzzer 9

#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, 600);
  }
  else if(interval > 500){
    tone(pinBuzzer, 450, 800);
  }
}

void setup() {
  pinMode(TRIG_pin, OUTPUT);
  pinMode(ECHO_pin, INPUT);
  Serial.begin(9600);
  pinMode(pinBuzzer, OUTPUT);
  myservo.attach(10);
  myservo.write(90);

}

void loop() {
  tutupPalang();
  interval += 100;
  if(interval > 1000) interval = 0;

}

void tutupPalang() {
  float jarak = readDistanceCM();
  if(jarak > 0 && jarak < 200) {
    soundBuzzer();
    tutup();
  }
  else{
    buka();
    noTone(pinBuzzer);
  }
}

void tutup(){
  if(rotasi <= 90){
    myservo.write(rotasi);
    delay(100);
    rotasi+=4;
  }
  if(rotasi >= 90) rotasi = 90;
}

void buka(){
  if(rotasi <= 90){
    myservo.write(rotasi);
    delay(100);
    rotasi+=4;
  }
  if(rotasi >= 90) rotasi = 90;
}