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

#define DHTPIN 13
#define DHTTYPE DHT22

#define LED_GREEN 4
#define LED_YELLOW 5
#define LED_RED 6
#define BUZZER 7

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

void setup() {

  Serial.begin(9600);

  dht.begin();

  lcd.init();
  lcd.backlight();

  pinMode(LED_GREEN, OUTPUT);
  pinMode(LED_YELLOW, OUTPUT);
  pinMode(LED_RED, OUTPUT);
  pinMode(BUZZER, OUTPUT);

  lcd.setCursor(0,0);
  lcd.print("IoT Monitor");
  lcd.setCursor(0,1);
  lcd.print("Starting...");
  delay(2000);

  lcd.clear();
}

void loop() {

  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();

  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Sensor Error");
    lcd.setCursor(0,0);
    lcd.print("Sensor Error");
    delay(2000);
    return;
  }

  // Serial Output
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.print(" C  |  Humidity: ");
  Serial.print(humidity);
  Serial.println(" %");

  // LCD Display
  lcd.setCursor(0,0);
  lcd.print("Temp: ");
  lcd.print(temperature,1);
  lcd.print((char)223);
  lcd.print("C ");

  lcd.setCursor(0,1);
  lcd.print("Hum: ");
  lcd.print(humidity,1);
  lcd.print("% ");

  // Reset LEDs
  digitalWrite(LED_GREEN, LOW);
  digitalWrite(LED_YELLOW, LOW);
  digitalWrite(LED_RED, LOW);
  noTone(BUZZER);

  // Status Conditions
  if (temperature > 35 || humidity > 80) {

    digitalWrite(LED_RED, HIGH);
    tone(BUZZER, 1000);

  }
  else if (temperature > 28 || humidity > 65) {

    digitalWrite(LED_YELLOW, HIGH);

  }
  else {

    digitalWrite(LED_GREEN, HIGH);

  }

  delay(2000);
}