#define E_N 2
#define T_N 3
#define Aka 4
#define Midori 5

void setup() {
  Serial.begin(9600);
  pinMode(LED_BUILTIN,OUTPUT);
  pinMode(E_N,INPUT);
  pinMode(T_N,OUTPUT);
  pinMode(Aka,OUTPUT);
  pinMode(Midori,OUTPUT);
  // put your setup code here, to run once:
}
float readDistanceCM (){
  digitalWrite(T_N,LOW);
  delayMicroseconds(2);
  digitalWrite(T_N,HIGH);
  delayMicroseconds(10);
  digitalWrite(T_N,LOW);
  int duration = pulseIn(E_N,HIGH);
  return duration *0.034 / 2;
}
void loop() {
  digitalWrite(T_N,LOW);
  delayMicroseconds(2);
  digitalWrite(T_N,HIGH);
  delayMicroseconds(10);
  digitalWrite(T_N,LOW);
  int duration = pulseIn(E_N,HIGH);
  float distance = readDistanceCM ();
  Serial.print("Hasil Data=");
  Serial.println(readDistanceCM());
  delay (100);

if (distance < 50)
digitalWrite(Aka,HIGH);
else digitalWrite(Aka,LOW);
if (distance > 50)
tone(Midori,100);
else noTone(Midori);

  // put your main code here, to run repeatedly:

}