/**************************************************************************************************************
*  Project: DHT11 and I2C exercise project for students    |  Ver: 1.0    Date: 26.6.2024 |  by: Ciljak       *
*-------------------------------------------------------------------------------------------------------------*
* Project description:                                                                                        *
* Exercise for students include data read from DHT11 temperature/ humidity sensor and further display them on *
* LCD 16 x 2 display with I2C interface. After one successful conversion and display data is blinked green LED*
* interconected on arduino module. Project is created for engancing practical skills with real hw and         * 
* crossrereference them against wokwi simulation https://wokwi.com/projects/401734873955442689 .              *
***************************************************************************************************************
* Functions to implement/ implemented and changelog: (I) implemented, (T) to be done                          *
* 1. Reading data from DHT11 tem/ hum sensor and display them via serial interface. (I)                       *
* 2. Display obtained data also on 2x14 LCD with I2C interface. (I)                                           *
* 3. Expand output interface with green LED indicating end of conversion/ display with 500mS light on.        *
*                                                                                                             *
**************************************************************************************************************/

#include "DHT.h"
#include <Wire.h>
#include <LiquidCrystal_PCF8574.h>

#define DHTPIN 2     // Pin, na ktorý je pripojený DATA výstup DHT11
#define DHTTYPE DHT22   // Definovanie typu snímača DHT11
#define LEDPIN 13     // Pin, na ktorý je pripojena LED bliknuca po refreshi údajov

// I2C connection of LCD is A4 - SDA and A5 - SCL line

DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_PCF8574 lcd(0x27); // Inicializácia LCD displeja s I2C adresou 0x27

void setup() {
  Serial.begin(9600); 
  pinMode(LEDPIN,OUTPUT);
  dht.begin(); 
  lcd.begin(16, 2);  // Spustenie LCD displeja s rozmermi 16x2 znaky
  lcd.setBacklight(255); // Zapnutie podsvietenia
  Serial.println("DHT11 sensor and LCD setup completed.");
}

void loop() {
  // Čítanie vlhkosti a teploty
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();

  // Kontrola, či čítanie bolo úspešné
  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read from DHT sensor!");
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Sensor error!");
    return;
  }

  // Vypísanie hodnôt na sériové rozhranie
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" *C");

  // Vypísanie hodnôt na LCD displej
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Humidity: ");
  lcd.print(humidity);
  lcd.print(" %");
  lcd.setCursor(0, 1);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print(" C");
  
  // Pauza pred ďalším čítaním
  delay(2000); 
  // Bliknutie po programovej slučke trvajuce 0,5S
  digitalWrite(LEDPIN,HIGH);
  delay(500);
  digitalWrite(LEDPIN,LOW);

}