int pirState = LOW;
#define Buzzer 4
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);

int interval = 5000;
long previousMillis = 0;
int IntervalR = 3000;    // Interval at which to toggle LED3 (milliseconds)
long previousMillisR = 0;  
bool ledStateR = LOW;

void setup() 
{
  // put your setup code here, to run once:
  Serial.begin(115200);

  pinMode(17, INPUT);
  pinMode(23, OUTPUT);
  pinMode(18, OUTPUT);
  Serial.begin(9600);

  pinMode(Buzzer, OUTPUT);
  lcd.init();  //set LCD 
  lcd.backlight();
}


void loop()
{
  const int IP = digitalRead(17);
  delay(100);
  long currentMillis = millis();
  if (currentMillis - previousMillis >= interval)
  {
    previousMillis = currentMillis;
    if (IP == 1)  // If motion is detected by the PIR sensor
    {
      digitalWrite(23, HIGH); 
      digitalWrite(18, LOW);
      if (pirState == LOW)  // Update pirState to indicate motion detection
        {
          Serial.println("Bin is opening!");
          lcd.clear();
          lcd.setCursor(1,0);
          lcd.print("Bin is opening");
          pirState = HIGH;
        }   
      else 
        {
          if (pirState == HIGH)  // Update pirState to indicate motion detection
            {
              Serial.println("Bin is closing...");
              lcd.clear();
              lcd.setCursor(1,0);
              lcd.print("Bin is closing");
              pirState = LOW;
              delay(3000);
              Serial.println("Bin is closed.");
              lcd.clear();
              lcd.setCursor(0,0);
              lcd.print("Bin is closed...");
              delay(500);
              digitalWrite(Buzzer, HIGH); //buzzer make sound
              delay(100);
              digitalWrite(Buzzer, LOW);
              digitalWrite(23, LOW);
              digitalWrite(18, HIGH);
            }
            digitalWrite(23, LOW);
            digitalWrite(18, HIGH);

        }
      }
  }
}