#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
#define echoPin A0
#define trigPin A1
#define led 2
  long durasi;
  int jarak, jarak_max = 20;
void setup() {
 lcd.init();
 lcd.begin(16,2);
 lcd.backlight();
 pinMode(trigPin, OUTPUT);
 pinMode(echoPin, INPUT);
 pinMode(led, OUTPUT);
 Serial.begin(9600);
}
void loop() {
 digitalWrite(trigPin, LOW);
 delayMicroseconds(2); 
 digitalWrite(trigPin, HIGH);
 delayMicroseconds(10);
 digitalWrite(trigPin, LOW);
durasi = pulseIn(echoPin, HIGH);
jarak = durasi * 0.034 / 2;
 lcd.setCursor(0,0);
 lcd.print("Jarak:");
 lcd.print(jarak);
 lcd.print("   cm");
 Serial.print("Jarak : ");
 Serial.print(jarak);
 Serial.println(" cm");
 delay(1000);

if (jarak < jarak_max){
 digitalWrite(led, HIGH);
 lcd.setCursor(0,2);
 lcd.print("Out of Range");
}
else {
 digitalWrite(led, LOW);
 lcd.setCursor(0,2);
 lcd.print("In Range");
}
delay(1000);
}