#include <LiquidCrystal_I2C.h>
#define I2C_ADDR 0x27
#define LCD_COLUMNS 16
#define LCD_LINES 2
#define merah 10
#define biru 11
#define kuning 12

LiquidCrystal_I2C lcd('I2_ADDR',  LCD_COLUMNS,  LCD_LINES);
long bacaJarak (int triggerPin,  int echoPin)

{
  pinMode(merah, OUTPUT);
  pinMode(biru,  OUTPUT);
  pinMode(kuning,  OUTPUT);
  pinMode(7, OUTPUT);
  digitalWrite(7, LOW);
  digitalWrite(7, HIGH);
  delayMicroseconds(10);
  digitalWrite(7, LOW);
  pinMode(8, INPUT);
  return pulseIn(8, HIGH);
  
}

void setup() 
{
  Serial. begin(9600);
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Sensor Jarak");
  delay(1000);
  lcd.clear();

}

void loop()
 {
  int cm = 0;
  cm = (0, 03446 * bacaJarak(38, 40))/2;
  lcd.clear();
  lcd.print("Jarak Benda");
  lcd.setCursor(0,1);
  lcd.print("= ");
  Serial.print(cm);
  Serial.println("cm");
  lcd.print(cm);
  lcd.print(" cm");
  lcd.setCursor(0,1);


if(cm < 5)
{
  digitalWrite(merah, HIGH);
  digitalWrite(biru, LOW);
  digitalWrite(kuning, LOW);
} else if(cm >= 5 && cm <=15)

{
  digitalWrite(biru, HIGH);
  digitalWrite(merah, LOW);
  digitalWrite(kuning, LOW);
} else if(cm > 15)

{
  digitalWrite(kuning, HIGH);
  digitalWrite(biru, LOW);
  digitalWrite(merah, LOW);
}
delay(1000);
}