#include <Servo.h>

int ECHO = 2;
int TRIG = 3;

Servo SERVO;

void setup() {
  Serial.begin(115200);
  pinMode(ECHO, INPUT);
  pinMode(TRIG, OUTPUT);
  SERVO.attach(5);
}

void loop() {

  float distance = readDistance();

  distance <= 100 ? SERVO.write(0) : SERVO.write(90);

  Serial.print("JARAK : ");
  Serial.println(distance);
  delay(800);

}

float readDistance() {
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);

  int duration = pulseIn(ECHO, HIGH);
  // return duration * 0.034 / 2 + 1;
  return duration / 58;
}