#include <DHT.h> // Include DHT library

#define DHTPIN 4     // Define the pin for DHT sensor data
#define DHTTYPE DHT22 // Define the type of DHT sensor you're using

// Define ultrasonic sensor pins
#define TRIGGER_PIN 2
#define ECHO_PIN 3

// Define LDR sensor pin
#define LDR_PIN A0

// Define LED pin
#define LED_PIN 13

// Initialize DHT sensor
DHT dht(DHTPIN, DHTTYPE);

// Function to read LDR sensor
int readLDR() {
  return analogRead(LDR_PIN);
}

// Function to read ultrasonic sensor
long readUltrasonic() {
  long duration;
  digitalWrite(TRIGGER_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGGER_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN, LOW);
  duration = pulseIn(ECHO_PIN, HIGH);
  return (duration / 2) / 29.1; // Calculate distance in centimeters
}

// Function to read temperature and humidity using DHT sensor
void readTempHumidity(float& temperature, float& humidity) {
  humidity = dht.readHumidity();
  temperature = dht.readTemperature();
}

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

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

  // Set LED pin as output
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  // Define array
  int sensorArray[] = {1, 2, 3};

  for (int i = 0; i < 3; i++) {
    int sensor = sensorArray[i];

    if (sensor == 1) {
      // Read LDR sensor
      int ldrValue = readLDR();
      if (ldrValue < 500) { // Assuming "low intensity" means a value below 500
        digitalWrite(LED_PIN, HIGH); // Turn on LED
      } else {
        digitalWrite(LED_PIN, LOW); // Turn off LED
      }
      Serial.print("Reading LDR sensor: ");
      Serial.println(ldrValue); // Print LDR value
    }

    if (sensor == 2) {
      // Read ultrasonic sensor
      long distance = readUltrasonic();
      // Check if object is closer than 20 cm
      if (distance < 20) {
        digitalWrite(LED_PIN, HIGH); // Turn on LED
      } else {
        digitalWrite(LED_PIN, LOW); // Turn off LED
      }
      Serial.print("Distance: ");
      Serial.print(distance);
      Serial.println(" cm");
    }

    if (sensor == 3) {
      // Read temperature and humidity using DHT sensor
      float humidity, temperature;
      readTempHumidity(temperature, humidity);

      // Check if readings are valid
      if (isnan(humidity) || isnan(temperature)) {
        Serial.println("Failed to read from DHT sensor!");
      } else {
        Serial.print("Humidity: ");
        Serial.print(humidity);
        Serial.print("%, Temperature: ");
        Serial.print(temperature);
        Serial.println("°C");
      }
    }

    // Wait a short delay between measurements
    delay(1000);
  }
}