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

#define pinBuzzer 2
#define pinServo 3
#define pinEcho 4
#define pinTrigger 5
#define pinManual A0
#define LED_1 12
#define LED_2 13

LiquidCrystal_I2C lcd(0x27, 20, 4);
Servo myservo;
int valPalang;

void setup() {
  pinMode(pinBuzzer, OUTPUT);
  pinMode(pinServo, OUTPUT);
  pinMode(pinEcho, INPUT);
  pinMode(pinTrigger, OUTPUT);
  pinMode(LED_1, OUTPUT);
  pinMode(LED_2, OUTPUT);

  myservo.attach(3);
  lcd.init();
  lcd.backlight();
  myservo.write(0);
}

float readDistanceCM() {
  digitalWrite(pinTrigger, LOW);
  delayMicroseconds(2);
  digitalWrite(pinTrigger, HIGH);
  delayMicroseconds(10);
  digitalWrite(pinTrigger, LOW);
  int duration = pulseIn(pinEcho, HIGH);
  return duration * 0.034 / 2;
}

void loop() {
  float distance = readDistanceCM();
  lcd.setCursor(0,0);
  lcd.print("Jarak KA:");
  lcd.setCursor(11,0);
  lcd.print(distance);

  delay(100);

  if (distance < 100){
    lcd.setCursor(2,1);
    lcd.print("KA Melintas");
    tone(pinBuzzer,1000);
    flipflop();
    valPalang = analogRead(pinManual);
    valPalang = map(valPalang , 0,1023, 0, 180 );
    myservo.write(valPalang);
    delay(15);
    
  }else{
    myservo.write(0);
    noTone(pinBuzzer);
    lcd.setCursor(6,1);
    lcd.print("Aman");
  }
  
}


void flipflop(){
  digitalWrite(LED_1, HIGH);
  delay(1000);
  digitalWrite(LED_1, LOW);
  digitalWrite(LED_2 , HIGH);
  delay(1000);
  digitalWrite(LED_2, LOW);
}