#include <Servo.h>
#include <LiquidCrystal_I2C.h>

#define I2C_ADDR 0x27
#define LCD_COLUMNS 20
#define LCD_LINES 4

LiquidCrystal_I2C lcd(I2C_ADDR,LCD_COLUMNS,LCD_LINES);
#define ECHO_PIN 3
#define TRIG_PIN 2
#define LAMPUMERAH 6
#define LAMPUIJO 7
#define pinBuzzer 5

Servo myservo;
const int potpin = A0;

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

  pinMode(LAMPUMERAH, OUTPUT);
  pinMode(LAMPUIJO, OUTPUT);
  
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  Serial.begin(115200);
  pinMode(pinBuzzer, OUTPUT);
  myservo.attach(9);

  // this part will show and write all the output processed by arduino
  lcd.setCursor(6,0);
  lcd.print("Welcome");
  lcd.setCursor(2,1);
  lcd.print("Automatic gate");
  lcd.setCursor(7, 2);
  lcd.print("Enjoy!");

  delay(4000);
  lcd.clear();
}

float readDistanceCM() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  return pulseIn(ECHO_PIN, HIGH) * 0.034 / 2.0;
}

void loop() {
  float distance = readDistanceCM();
  Serial.print("Measured distance: ");
  Serial.println(distance);

  if (distance <= 200.0) {
    myservo.write(90);
    delay(15);
    tone(pinBuzzer, 1000);
    delay(200);
    tone(pinBuzzer, 500);
    delay(200);
    digitalWrite(LAMPUMERAH, HIGH);
    lcd.setCursor(0, 2);
    lcd.print("AWAS BAHAYA");

  } else {
    myservo.write(0);
    noTone(pinBuzzer);
    digitalWrite(LAMPUIJO, HIGH);
    lcd.setCursor(0, 2);
    lcd.print("AMAN BRO");
  }

  lcd.setCursor(0, 0);
  lcd.print("DISTANCE: ");
  lcd.setCursor(10, 0);
  lcd.print(distance);

  Serial.print("jarak: ");
  Serial.println(distance);
}