#include "DHT.h"
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16,2 );

#define DHTPIN 4
#define DHTTYPE 22
#define GAS 34 
#define BUZZ 2
#define LED 16
#define RELAY 26
int nilaigas;
int batasgas = 3000;

DHT dht(DHTPIN , DHTTYPE);

void setup() {
  // put your setup code here, to run once:
  pinMode(GAS, INPUT);
  pinMode(LED,OUTPUT);
  pinMode(BUZZ,OUTPUT);
  pinMode(RELAY,OUTPUT);

  Serial.begin(115200);
  
  dht.begin();
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("GALANGS");
  lcd.setCursor(0,1);
  lcd.print ("XII ELIND 4");
  delay(3000);
  lcd.clear();

}

void loop() {
  // put your main code here, to run repeatedly:

  float hum = dht.readHumidity();
  float temp = dht.readTemperature();
  int nilaigas = (analogRead(GAS));

  if (isnan(hum) || isnan(temp)){
    Serial.println ("Gagal baca sensor");
    lcd.clear();
    lcd.print("Sensor error");
    delay(1000);
    return;

  }

 if(nilaigas > batasgas) {
 lcd.setCursor(0,0);
 lcd.print("T: ");
 lcd.print(temp);
 lcd.print("C    ");
 lcd.setCursor(0,1);
 lcd.print("H: ");
 lcd.print(hum);
 delay(3000);
 lcd.clear();
 lcd.setCursor(0,0);
 lcd.print("GAS GA NYELOW");
 tone(BUZZ, 1000);
 digitalWrite(RELAY,HIGH);
 digitalWrite(LED,HIGH);
 delay(3000);

 }else{
  digitalWrite(RELAY,HIGH);
  digitalWrite(LED, LOW);
  noTone(BUZZ);

  lcd.setCursor(0,0);
  lcd.print("T: ");
  lcd.print(temp);
  lcd.print("C    ");
  lcd.setCursor(0,1);
  lcd.print("H: ");
  lcd.print(hum);
  delay(3000);
  lcd.clear();

 }


 }