#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);
int lampuKuning = 11;
int lampuMerah = 12;
int lampuHijau = 10;

long Jarak (int triggerPin, int echoPin) {
  pinMode(triggerPin, OUTPUT);
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPin, HIGH); 
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  pinMode(echoPin, INPUT);
  return pulseIn(echoPin, HIGH);
}

void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
}

void loop() {
  int jaraknya = 0; // reset jarak ke 0
  jaraknya = (0.03446 * Jarak(7,8))/2;
  Serial.print(jaraknya);
  Serial.println(" CM");
  lcd.clear();

  if (jaraknya > 15) {
    digitalWrite(lampuHijau, HIGH);
    digitalWrite(lampuKuning, LOW);
    digitalWrite(lampuMerah, LOW);
    lcd.setCursor(0,0);
    lcd.print(jaraknya);
    lcd.print(" CM");
    lcd.setCursor(0,1);
    lcd.print("Jarak Aman");
  }
  else if(jaraknya >= 5 && jaraknya < 15) {
    digitalWrite(lampuKuning, HIGH);
    digitalWrite(lampuMerah, LOW);
    digitalWrite(lampuHijau, LOW);
    lcd.setCursor(0,0);
    lcd.print(jaraknya);
    lcd.print(" CM");
    lcd.setCursor(0,1);
    lcd.print("Jarak Hati-Hati");
  }
  else if(jaraknya < 5) {
    digitalWrite(lampuMerah, HIGH);
    digitalWrite(lampuKuning, LOW);
    digitalWrite(lampuHijau, LOW);
    lcd.setCursor(0,0);
    lcd.print(jaraknya);
    lcd.print(" CM");
    lcd.setCursor(0,1);
    lcd.print("Jarak Bahaya");
  }
  delay(200);

  }