#include <Servo.h>
Servo servoku;

unsigned long previousMillis = 0;
float i=0;

void setup() {
  Serial.begin(115200);
  pinMode(4, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(2, INPUT);
  pinMode(13, OUTPUT);
  servoku.attach(5);
}

void loop() {
  float jarak = nilaiSensor();
  
  if (jarak <= 50) {
    tutupPalang();
    tone(4, 200);
    digitalWrite(13, HIGH);
    delay(500);
    tone(4, 175);
    digitalWrite(13, LOW);
    delay(500);
  } else {
    noTone(4);
    digitalWrite(13, LOW);
    bukaPalang();
    delay(1000);
  }
  
  Serial.println("Jarak: " + String(jarak, 0) + " meter");
}

float nilaiSensor() {
  digitalWrite(3, HIGH);
  delayMicroseconds(10);
  digitalWrite(3, LOW);
  int duration = pulseIn(2, HIGH);
  return map((duration / 58), 1, 400, 0, 100);
}

void tutupPalang() {
  while (i<=90) {
    servoku.write(i);
    i++;
    delay(50);
  }
}

void bukaPalang() {
  while (i>=0) {
    servoku.write(i);
    i--;
    delay(50);
  }
}