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

// Define the DHT pin and type
#define DHT_PIN 21 // The ESP8266 pin D7 connected to DHT11 sensor
#define DHT_TYPE DHT11

// Initialize the LCD with I2C address 0x27, 16 columns and 2 rows
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Initialize the DHT sensor
DHT dht11(DHT_PIN, DHT_TYPE);

void setup() {
  // Initialize I2C with custom SDA and SCL pins
  Wire.begin(18, 19); // (SDA, SCL)
  
  lcd.init();          // Initialize the LCD I2C display
  lcd.backlight();     // Turn on the backlight
  dht11.begin();       // Initialize the DHT sensor
}

void loop() {
  float humi = dht11.readHumidity();            // Read humidity
  float temperature_C = dht11.readTemperature(); // Read temperature

  lcd.clear();
  
  // Check if the readings are valid
  if (isnan(temperature_C) || isnan(humi)) {
    lcd.setCursor(0, 0);
    lcd.print("Failed");
  } else {
    lcd.setCursor(0, 0);  // Display position
    lcd.print("Temp: ");
    lcd.print(temperature_C);     // Display the temperature
    lcd.print("°C");

    lcd.setCursor(0, 1);  // Display position
    lcd.print("Humi: ");
    lcd.print(humi);      // Display the humidity
    lcd.print("%");
  }

  // Wait 2 seconds between readings
  delay(2000);
}