/*
 * Arduino Weather Station
 * DHT22 Temperature & Humidity Sensor with LCD Display
 * Created for Wokwi Simulator
 */

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

// DHT22 Sensor Configuration
#define DHTPIN 2        // DHT22 data pin connected to Arduino pin 2
#define DHTTYPE DHT22   // DHT 22 (AM2302)

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

// LCD Configuration (RS, E, D4, D5, D6, D7)
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

// Custom characters for degree symbol
byte degreeSymbol[8] = {
  0b00110,
  0b01001,
  0b01001,
  0b00110,
  0b00000,
  0b00000,
  0b00000,
  0b00000
};

// Custom character for humidity drop
byte dropSymbol[8] = {
  0b00100,
  0b00100,
  0b01010,
  0b01010,
  0b10001,
  0b10001,
  0b10001,
  0b01110
};

void setup() {
  // Initialize serial communication for debugging
  Serial.begin(9600);
  Serial.println("Weather Station Initializing...");
  
  // Initialize DHT sensor
  dht.begin();
  
  // Initialize LCD (16x2 display)
  lcd.begin(16, 2);
  
  // Create custom characters
  lcd.createChar(0, degreeSymbol);
  lcd.createChar(1, dropSymbol);
  
  // Display welcome message
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Weather Station");
  lcd.setCursor(0, 1);
  lcd.print("Initializing...");
  delay(2000);
  lcd.clear();
}

void loop() {
  // Wait a few seconds between measurements
  delay(2000);
  
  // Read humidity
  float humidity = dht.readHumidity();
  
  // Read temperature in Celsius
  float temperatureC = dht.readTemperature();
  
  // Read temperature in Fahrenheit
  float temperatureF = dht.readTemperature(true);
  
  // Check if any reads failed
  if (isnan(humidity) || isnan(temperatureC) || isnan(temperatureF)) {
    Serial.println("Failed to read from DHT sensor!");
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Sensor Error!");
    lcd.setCursor(0, 1);
    lcd.print("Check Connection");
    return;
  }
  
  // Calculate heat index in Fahrenheit
  float heatIndexF = dht.computeHeatIndex(temperatureF, humidity);
  
  // Calculate heat index in Celsius
  float heatIndexC = dht.computeHeatIndex(temperatureC, humidity, false);
  
  // Print to Serial Monitor for debugging
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print("%  Temperature: ");
  Serial.print(temperatureC);
  Serial.print("°C / ");
  Serial.print(temperatureF);
  Serial.print("°F  Heat Index: ");
  Serial.print(heatIndexC);
  Serial.println("°C");
  
  // Display on LCD - Line 1: Temperature
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperatureC, 1);  // 1 decimal place
  lcd.write(byte(0));          // Degree symbol
  lcd.print("C ");
  lcd.print(temperatureF, 1);
  lcd.write(byte(0));
  lcd.print("F");
  
  // Display on LCD - Line 2: Humidity
  lcd.setCursor(0, 1);
  lcd.print("Humidity: ");
  lcd.print(humidity, 1);
  lcd.print("%");
  lcd.write(byte(1));          // Drop symbol
  
  // Alternate display every 5 seconds to show heat index
  delay(5000);
  
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Heat Index:");
  lcd.setCursor(0, 1);
  lcd.print(heatIndexC, 1);
  lcd.write(byte(0));
  lcd.print("C / ");
  lcd.print(heatIndexF, 1);
  lcd.write(byte(0));
  lcd.print("F");
  
  delay(3000);
}