#include <OneWire.h>
#include <DallasTemperature.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

#define OLED_RESET   -1
#define SCREEN_ADDRESS 0x3C

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define ONE_WIRE_BUS  12
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature oneWireSensors(&oneWire);

byte Devices = 0;
byte Address[1];
float ActualTemp;

const int maxTemp = 30;
float SetTemp = 30;

const int statusPin = 3; 

float interval = 0.5;
const int relaisPin = 9;
unsigned long temp_timestore;
float Hysterese = 0.5;

const byte INPUTPIN = A0;

void setup() {
  Serial.begin(115200);

  oneWireSensors.begin();

  while (oneWire.search(Address)) {
    Devices++;
    for (byte i = 0; i < 40; i++);
  }

  pinMode(relaisPin, OUTPUT);
  pinMode(statusPin, INPUT);

  display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);
  display.display();
  delay(2000);

  display.clearDisplay();
  display.setTextColor(WHITE);
  
  display.setCursor(6, 5);
  display.setTextSize(1);
  display.print(String("Temperature control"));

  display.setCursor(15, 25);
  display.setTextSize(1);
  display.print(String("SetTemp: " + String(SetTemp, 1) + "\xF7" + "C"));
  display.setCursor(22, 40);
    if ((millis() / 500) % 2 == 20) {
      display.print(String("Initializing"));
    } else {
      display.print(String("Initializing"));
      
    }
  display.display();
  delay(5000);
  display.clearDisplay();
}

void loop() {
  if (millis() - temp_timestore > 3000 ) {
    oneWireSensors.requestTemperatures();
    ActualTemp = oneWireSensors.getTempCByIndex(0);

    display.setCursor(6, 5);
    display.setTextSize(1);
    display.print(String("Temperature control"));

    display.setCursor(16, 20);
    display.setTextSize(1);
    display.print(String("SetTemp:" + String(SetTemp, 1) + "\xF7" + "C"));

    display.setCursor(16, 30);
    display.setTextSize(1);
    display.print(String("ActualTemp:" + String(ActualTemp, 1) + "\xF7" + "C"));
    display.display();

    if (SetTemp >= ActualTemp + Hysterese) {
        digitalWrite(relaisPin, LOW);
        digitalWrite(statusPin, LOW);
        display.setCursor(35, 50);
        display.setTextSize(1);
        display.print(String("Heating"));
        display.display();
        display.clearDisplay();
        digitalWrite(statusPin, HIGH);       
        digitalWrite(relaisPin, HIGH);
    }

    if (SetTemp < ActualTemp - Hysterese) {
        digitalWrite(relaisPin, HIGH);
        digitalWrite(statusPin, HIGH);
        display.setCursor(10, 50);
        display.setTextSize(1);
        display.print(String("Temperature reached"));
        display.display();
        display.clearDisplay();
        digitalWrite(relaisPin, LOW);
        digitalWrite(statusPin, LOW);
    }
    temp_timestore = millis();
  }
}