#define EP 2
#define TP 3

float X=400/397.64;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(TP, OUTPUT);
  pinMode(EP, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(TP, LOW);
  delayMicroseconds(10);
  digitalWrite(TP, HIGH);
  delayMicroseconds(10);
  digitalWrite(TP, LOW);

  int waktu=pulseIn(EP,HIGH);
  float jarak=waktu*0.034*X/2;

  Serial.print("jarak= ");
  Serial.print(jarak);
  Serial.println("cm");
  delay(100);
}