#include <LiquidCrystal.h>
#include <DHT.h>

// Pin assignments
const int ledPin = 5;       // digital pin 5 for LED
const int ldrPin = A0;      // analog pin 0 for LDR
const int buzzerPin = 6;    // digital pin 6 for Buzzer
const int pirPin = 7;       // digital pin 7 for PIR sensor
const int relayPin = 8;     // digital pin 8 for Relay
const int dhtPin = 9;       // digital pin 9 for DHT sensor
const int rs = 10, en = 11, d4 = 12, d5 = 13, d6 = 14, d7 = 15; // LCD pins

// Initialize the DHT sensor
#define DHTTYPE DHT11   // Define the type of DHT sensor used (DHT11 or DHT22)
DHT dht(dhtPin, DHTTYPE);

// Initialize the LCD library with the LCD pin numbers
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup() {
  // Initialize serial communication
  Serial.begin(9600);

  // Initialize pin modes
  pinMode(ledPin, OUTPUT);  // LED as output
  pinMode(ldrPin, INPUT);   // LDR as input
  pinMode(buzzerPin, OUTPUT); // Buzzer as output
  pinMode(pirPin, INPUT);   // PIR sensor as input
  pinMode(relayPin, OUTPUT); // Relay as output

  // Initialize the LCD
  lcd.begin(16, 2);  // Set up the LCD's number of columns and rows
  lcd.print("System Ready");

  // Initialize the DHT sensor
  dht.begin();
}

void loop() {
  // Read the LDR sensor value
  int ldrStatus = analogRead(ldrPin);

  // Read the DHT sensor values
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();

  // Check if any reads failed and exit early (to try again).
  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Display temperature and humidity on the LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print(" C");
  lcd.setCursor(0, 1);
  lcd.print("Humidity: ");
  lcd.print(humidity);
  lcd.print(" %");

  // Check if it's dark (LDR value <= 200)
  if (ldrStatus <= 200) {
    digitalWrite(ledPin, HIGH); // Turn on the LED
    Serial.print("Darkness detected, turn on the LED: ");
    Serial.println(ldrStatus);

    // Read the PIR sensor value
    int pirStatus = digitalRead(pirPin);

    // Check if motion is detected
    if (pirStatus == HIGH) {
      tone(buzzerPin, 1000); // Emit a tone of 1000 Hz on the Buzzer
      digitalWrite(relayPin, HIGH);  // Activate the Relay
      Serial.println("Motion detected, activating buzzer and relay");
    } else {
      noTone(buzzerPin);  // Stop the tone on the Buzzer
      digitalWrite(relayPin, LOW);   // Deactivate the Relay
      Serial.println("No motion detected, buzzer and relay off");
    }
  } else {
    digitalWrite(ledPin, LOW); // Turn off the LED
    Serial.print("Sufficient light detected, turn off the LED: ");
    Serial.println(ldrStatus);

    // Ensure the buzzer and relay are off
    noTone(buzzerPin); // Stop the tone on the Buzzer
    digitalWrite(relayPin, LOW);
  }

  delay(2000); // Wait a few seconds between measurements
}