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

LiquidCrystal_I2C lcd(0x27, 16, 2);
#define DHTPIN 2
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

float H, T;
int buzzer = 12;

void setup() {
  lcd.init(); lcd.backlight();
  Serial.begin(115200);
  dht.begin();
  pinMode(13, OUTPUT); pinMode(buzzer, OUTPUT);
  pinMode(9, OUTPUT); pinMode(10, OUTPUT); pinMode(11, OUTPUT);
}

void loop() {
  delay(2000);
  H = dht.readHumidity();
  T = dht.readTemperature();

  Serial.print("Humidity: "); Serial.print(H); Serial.println(" %; ");
  Serial.print("Temperature: "); Serial.print(T); Serial.println(" Celsius.\n");

  if(H >= 70.00 && T >= 30.00) {
    digitalWrite(9, HIGH); digitalWrite(10, LOW); digitalWrite(11, LOW);
    lcd.println("   Too warm!    "); lcd.setCursor(0, 1); lcd.println("   Cool down!   "); lcd.setCursor(0, 0);
    digitalWrite(buzzer, 1); tone(buzzer, 900, 100); delay(400); digitalWrite(buzzer, 0); tone(buzzer, 900, 100); delay(400);
    digitalWrite(buzzer, 1); tone(buzzer, 900, 100); delay(400); digitalWrite(buzzer, 0); tone(buzzer, 900, 100); delay(400);
  } else {
    digitalWrite(9, LOW); digitalWrite(10, LOW); digitalWrite(11, HIGH);
    lcd.println("Temp. & hum. are"); lcd.setCursor(0, 1); lcd.println("in normal limits"); lcd.setCursor(0, 0);
    digitalWrite(buzzer, 0);
  }
  
  if(H < 70.00 && T >= 30.00) {
    digitalWrite(9, LOW); digitalWrite(10, HIGH); digitalWrite(11, LOW);
    lcd.println("Warning!        "); lcd.setCursor(0, 1); lcd.println("Temp. too high! "); lcd.setCursor(0, 0);
    digitalWrite(buzzer, 1); tone(buzzer, 400, 400); delay(400); digitalWrite(buzzer, 0); tone(buzzer, 400, 400); delay(400);
  }
  
  if(H >= 70.00 && T < 30.00) {
    digitalWrite(9, LOW); digitalWrite(10, HIGH); digitalWrite(11, LOW);
    lcd.println("Warning!        "); lcd.setCursor(0, 1); lcd.println("Hum. too high!  "); lcd.setCursor(0, 0);
    digitalWrite(buzzer, 1); tone(buzzer, 400, 400); delay(400); digitalWrite(buzzer, 0); tone(buzzer, 400, 400); delay(400);
  }
}