#include <DHT.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

#define DHTPIN 2
#define DHTTYPE DHT22
#define trigPin 9
#define echoPin 8
#define pirPin 7
#define buzzer 6
#define ledPin 5
#define buttonPin 4

DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_I2C lcd(0x27, 16, 2);

bool sensorActive = false;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(pirPin, INPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP);

  lcd.init();
  lcd.backlight();
  dht.begin();

  lcd.setCursor(0, 0);
  lcd.print("Press button to");
  lcd.setCursor(0, 1);
  lcd.print("activate sensors");
}

void loop() {
  // Check if button is pressed to toggle sensors on/off
  if (digitalRead(buttonPin) == LOW) {
    delay(300);  // Debounce delay
    sensorActive = !sensorActive;
    lcd.clear();
    if (sensorActive) {
      lcd.setCursor(0, 0);
      lcd.print("Sensors activated");
    } else {
      lcd.setCursor(0, 0);
      lcd.print("Sensors deactivated");
      noTone(buzzer); // Stop buzzer if active
      digitalWrite(ledPin, LOW); // Turn off LED
    }
  }

  if (sensorActive) {
    // DHT22 Sensor: Temperature and Humidity
    float temp = dht.readTemperature();
    float hum = dht.readHumidity();
    lcd.setCursor(0, 0);
    lcd.print("Temp: ");
    lcd.print(temp);
    lcd.print(" C");
    lcd.setCursor(0, 1);
    lcd.print("Hum: ");
    lcd.print(hum);
    lcd.print(" %");

    // Ultrasonic Sensor: Distance Measurement
    long duration, distance;
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);
    duration = pulseIn(echoPin, HIGH);
    distance = duration * 0.034 / 2;

    if (distance < 50) {
      digitalWrite(ledPin, HIGH); // Turn on LED if distance < 50 cm
    } else {
      digitalWrite(ledPin, LOW);
    }

    // PIR Sensor: Motion Detection
    if (digitalRead(pirPin) == HIGH) {
      tone(buzzer, 1000); // Sound buzzer if motion detected
    } else {
      noTone(buzzer); // Stop buzzer if no motion
    }

    delay(1000); // Delay for sensor readings
  }
}