#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);

long readDistance(int triggerPin, int echoPin){
  pinMode(triggerPin, OUTPUT);
  digitalWrite(triggerPin, LOW);
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  pinMode(echoPin, INPUT);
  return pulseIn(echoPin, HIGH);
}

void setup() {
  lcd.init();
}

void loop() {
  int cm = 0;
  lcd.setCursor(0, 0);
  cm = (0.03446 * readDistance(3, 4))/2;
  lcd.print("Jarak : ");
  lcd.print(cm);
  lcd.println("cm");
  delay(500);
}