#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 20, 4);

#define PIN_TRIG 3
#define PIN_ECHO 2

#define BLUE_LED 7
#define GREEN_LED 8
#define YELLOW_LED 9
#define RED_LED 10

void setup() {

  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);

  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);


  lcd.init(); 
  lcd.backlight();

  lcd.setCursor(0, 0);            
  lcd.print("SMAN 1 TANGSEL");          
  lcd.setCursor(0, 1);            
  lcd.print("INFORMATIKA"); 
  lcd.setCursor(0, 2);            
  lcd.print("CINDAI DAN KEISYA");          
  lcd.setCursor(0, 3);            
  lcd.print("KELAS X-5"); 
  delay(2000);
  lcd.clear();  

}

void loop() {
  // Start a new measurement:
  digitalWrite(PIN_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(PIN_TRIG, LOW);

  // Read the result:
  int duration = pulseIn(PIN_ECHO, HIGH);
  int distance = ( duration / 2) / 29.1;

  lcd.setCursor(0, 0);
  lcd.print("Meteran Digital");   
  lcd.setCursor(0, 1);
  lcd.print("Ultra Sonic SR04");   
  lcd.setCursor(0, 3);
  lcd.print(String("Jarak : ")+String(distance)+String(" Cm"));   
  delay(200);

  if(distance > 250)
  {
    digitalWrite(10, HIGH);
    delay(200);
    digitalWrite(10, LOW);
  }
  else if(distance >= 151)
  {
    digitalWrite(9, HIGH);
    delay(200);
    digitalWrite(9, LOW);
  }
  else if(distance >= 75)
  {
    digitalWrite(8, HIGH);
    delay(200);
    digitalWrite(8, LOW);
  }
  else 
  {
    digitalWrite(7, HIGH);
    delay(200);
    digitalWrite(7, LOW);
  }
}