#include <Wire.h>
#include <hd44780.h>
#include <hd44780ioClass/hd44780_I2Cexp.h>

hd44780_I2Cexp lcd;

const int pirPin = 33;
const int ldrPin = 34; 
const int tempPin = 32; 
const int buzzerPin = 26; 
const int ledPin = 2; 

const float tempHighThreshold = 80; 
const int ldrLightThreshold = 800; 

void setup() {
  lcd.begin(16, 2, 0x27);
  lcd.init(); 
  lcd.backlight(); 

  pinMode(pirPin, INPUT);
  pinMode(ldrPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPin, OUTPUT);
}

void loop() {
  int pirState = digitalRead(pirPin);
  int ldrValue = analogRead(ldrPin);
  int tempValue = analogRead(tempPin);
  float temperature = map(tempValue, 0, 1023, -20, 100);

  if (pirState == HIGH) {
    lcd.setCursor(0, 1);
    lcd.print("object detected");
    tone(buzzerPin, 1000, 500); 
  } 
  else {
    lcd.setCursor(0, 1);
    lcd.print("               ");
    noTone(buzzerPin); 
  }

  if (ldrValue > ldrLightThreshold) {
    digitalWrite(ledPin, HIGH); 
  } 
  else {
    digitalWrite(ledPin, LOW); 
   
  }
  
  if (temperature < tempHighThreshold) {  
    lcd.setCursor(0, 0);
    lcd.print("High Temperature");
    tone(buzzerPin, 2000, 500);  
  
  }
  else {
    lcd.setCursor(0, 0);
    lcd.print("Temperature Ok   ");
  }

  Serial.print("LDR Value: ");
  Serial.print(ldrValue);
  Serial.print("\tTemperature: ");
  Serial.print(temperature);
  Serial.print(" C\tPIR State: ");
  Serial.println(pirState);

  delay(1000);
}