#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
#include <DHT.h>
LiquidCrystal_I2C lcd(0x27,16,4);
int gas = A3;
const int DHTPIN = 2;
#define DHTTYPE DHT22 // Loại cảm biến DHT11
float humidity;
float temperature;
int gas_value;
DHT dht(DHTPIN, DHTTYPE);
int speaker = 3;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  lcd.init();                    
  lcd.backlight();
  dht.begin();
  pinMode(speaker, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  read_sensor();
}
void read_sensor(){
  humidity = dht.readHumidity();
  temperature = dht.readTemperature();
  gas_value = analogRead(gas);
  if (gas_value>500) tone(speaker, 1000);
  else noTone(speaker);
  print_lcd();
  // Serial.println(humidity);
  // Serial.println(temperature);
  // Serial.println(gas_value);
  // delay(1000);
}

void print_lcd(){
  String line1 = "Temp:"+ String(temperature) + "C";
  String line2 = "Hum :"+ String(humidity) + "%";
  String line3 = "GAS :"+ String(gas_value)+"        ";
  lcd.setCursor(0,0);
  lcd.print(line1);
  lcd.setCursor(0,1);
  lcd.print(line2);
  lcd.setCursor(0,2);
  lcd.print(line3);
}