#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <DHT_U.h>
#include <LCD_I2C.h>
#include <EEPROM.h>
int EEPROM_lgt = 8;
int EEPROM_add = 0;
int EEPROM_lst = 0;
long EEPROM_ok = 0;

bool useCelsius = true;
DHT dht(11, DHT11);
LCD_I2C lcd(0x27, 16, 2); // Default address of most PCF8574 modules, change according
#define button4 4
#define pot A0
int myPos = 0;
int myPosOld = 0;
int myPosCalc = 0;
float celsius = 0;
float fahrenheit = 0;
float humidity = 0;
float saved_Celsius = 0;
float saved_Frenheit = 0;
//-------------------------------------------------------------------
void setup() {
  Serial.begin(9600);
  pinMode(button4, INPUT_PULLUP);
  lcd.begin(); // If you are using more I2C devices using the Wire library use lcd.begin(false)
  lcd.backlight();
  dht.begin();
  celsius = dht.readTemperature();
  fahrenheit = dht.readTemperature(true);
  humidity = dht.readHumidity();
  if (EEPROM.get(0x03FC, EEPROM_ok) == 0x0A0A0A0A) {
    EEPROM.get(0x03F8, EEPROM_lst);
    Serial.println(EEPROM_ok, HEX);
    Serial.println(EEPROM_lst, HEX);
  }
  else {
    EEPROM.put(0x03FC, 0x0A0A0A0A);
    EEPROM.put(0x03F8, EEPROM_lst);
  }
  saving();
  lcd.setCursor(0, 0);
  lcd.print("     Celsius    ");
  lcd.setCursor(7, 1); //
  lcd.print(celsius); //
  lcd.print("C");
  lcd.print("       ");
}
//-------------------------------------------------------------------
void temperature() {
  celsius = dht.readTemperature();
  fahrenheit = dht.readTemperature(true);
  humidity = dht.readHumidity();
  useCelsius = !useCelsius;
  if (!useCelsius) {
    saving();
    lcd.setCursor(0, 0);
    lcd.print("   Fahrenheit   ");
    lcd.setCursor(7, 1); //
    lcd.print(fahrenheit); //
    lcd.print("F");
    lcd.print("       ");
  }
  else {
    saving();
    lcd.setCursor(0, 0);
    lcd.print("     Celsius    ");
    lcd.setCursor(7, 1); //
    lcd.print(celsius); //
    lcd.print("C");
    lcd.print("       ");
  }
}
//-------------------------------------------------------------------
void saving() {
  lcd.setCursor(0, 0);
  lcd.print("     SAVING    ");
  lcd.setCursor(0, 1);
  lcd.print("                 ");
  EEPROM.put(EEPROM_lst, celsius);
  EEPROM_lst += 4;
  EEPROM.put(EEPROM_lst, fahrenheit);
  EEPROM_lst += 4;
  if (EEPROM_lst >= 0x03F8) {
    EEPROM_lst >= 0x0;
  }
  EEPROM.put(0x03F8, EEPROM_lst);
  //Serial.println(EEPROM_lst, HEX);
  delay(100);
}
//-------------------------------------------------------------------
void loop() {
  if (digitalRead(button4) == LOW) {
    delay(30);
    if (digitalRead(button4) == LOW) {
      temperature();
    }
  }
  while (digitalRead(button4) == LOW) {}
  myPos = analogRead(pot);
  if (myPos != myPosOld) {
    myPosOld = myPos;
    myPosCalc = map(myPos, 0, 1024, 0, 256) * 4;
    EEPROM.get(myPosCalc, saved_Celsius);
    if (!isnan(saved_Celsius)) {
      Serial.print("EEPROM  ");
      Serial.print(myPosCalc);
      Serial.print(" = ");
      Serial.print(saved_Celsius);
      Serial.print(" C   ");
    }
    EEPROM.get(myPosCalc + 4, saved_Frenheit);
    if (!isnan(saved_Frenheit)) {
      Serial.print("EEPROM  ");
      Serial.print(myPosCalc + 4);
      Serial.print(" = ");
      Serial.print(saved_Frenheit);
      Serial.println( "F" );
    }
  }
}