// Include libraries
#include <DHT.h>  // DHT sensor library
#include <LiquidCrystal_I2C.h>  // LCD library
#include <Wire.h>  // Wire library for I2C communication

// Initialize LCD with address 0x27, 16 columns, and 2 rows
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Constants for DHT sensor
#define DHTPIN A3  // Pin where DHT sensor data is connected
#define DHTTYPE DHT11  // DHT 11 sensor type

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

// Variables for humidity and temperature
int h;  // Stores humidity value
int t;  // Stores temperature value

void setup() {
  // Start serial communication
  Serial.begin(9600);  
  Serial.println("Temperature and Humidity Sensor Test");

  // Initialize DHT sensor
  dht.begin();

  // Initialize LCD
  lcd.begin(16, 2);  // Set LCD size (16 characters and 2 rows)
  lcd.backlight();  // Turn on LCD backlight
}

void loop() {
  // Read humidity and temperature values from the sensor
  h = dht.readHumidity();
  t = dht.readTemperature();

  // Check if reading was successful
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor");
    return;  // Exit the loop if reading failed
  }

  // Print the values to the serial monitor
  Serial.print("Humidity: ");
  Serial.print(h);
  Serial.print(" %, Temp: ");
  Serial.print(t);
  Serial.println(" °C");

  // Display the results on the LCD
  lcd.clear();  // Clear the LCD screen
  
  // Set cursor to the first line, first column
  lcd.setCursor(0, 0);
  lcd.print("Humidity: ");
  lcd.print(h);
  lcd.print("%");

  // Set cursor to the second line, first column
  lcd.setCursor(0, 1);
  lcd.print("Temp: ");
  lcd.print(t);
  lcd.print("C");

  // Delay for 1 second before taking the next reading
  delay(1000);
}