#define ECHO_PIN 3
#define TRIG_PIN 2
#define pinBuzzer 5
#define LCD_ADDR 0x27
#define LCD_COLUMNS 16
#define LCD_ROWS 2



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

LiquidCrystal_I2C lcd(0x27, 20, 4);

Servo myservo;
int rotasi = 90;
int interval = 0;


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

void soundBuzzer(){
if(interval < 500){
  tone(pinBuzzer, 250);
}else
if(interval > 500){
  tone(pinBuzzer, 100,800);
};
}

void setup() {

pinMode(TRIG_PIN, OUTPUT) ;
pinMode(ECHO_PIN, INPUT);
Serial.begin(115200) ;
pinMode(pinBuzzer, OUTPUT);
myservo.attach(9) ;
myservo.write(90) ;

  lcd.begin(16,2);
  lcd.init();
  lcd.backlight();

  lcd.setCursor(0,0);
  lcd.print("Jika Berlaku Masalah");

  lcd.setCursor(0,1);
  lcd.print("Sila Hubungi : ");

  lcd.setCursor(0,2);
  lcd.print("013-6087430 (Fashli)");

  lcd.setCursor(0,3);
  lcd.print("012-34567689 (Ali)");

}

void loop() {

tutupPalang();
interval +=100;
if(interval>1000) interval = 0;
}

void tutupPalang(){
float jarak = readDistanceCM();
if(jarak > 0 && jarak < 100 ){
soundBuzzer();
tutup();
  }else{
buka();
noTone(pinBuzzer) ;
  }

}

void tutup(){
if(rotasi <= 90){
myservo.write(rotasi) ;
delay(100);
rotasi--;
}
if(rotasi <= 0 ) rotasi = 0;

}

void buka(){
if(rotasi <= 90){
myservo.write(rotasi) ;
delay(100);
rotasi+=4;
}
if(rotasi >= 90 ) rotasi = 90;
}