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



#define BUTTON 6
#define LIMIT 20

uint8_t cas = LIMIT;
boolean stav = true; //1- bezi, 0-stoji

unsigned long previousMillis = 0;

int buttonState = LOW;
int lastButtonState = LOW;
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;


byte znak[8] = {
	0b00000,
	0b01010,
	0b11111,
	0b11111,
	0b01110,
	0b00100,
	0b00000,
	0b00000
};

void setup() {
  pinMode(BUTTON, INPUT);
  lcd.init();
  lcd.backlight();
  

  lcd.createChar(0, znak);
  lcd.setCursor(10, 0); // move cursor to (2, 0)
  lcd.write((byte)0);
}

void loop() {
  unsigned long currentMillis = millis();
  if(currentMillis-previousMillis >=1000 && stav){
    previousMillis = currentMillis;
    lcd.setCursor(5,1);
    zobraz();
  }
   if(cas==0){
    stav = false;
    tone(4,262,1000);
  }
  int reading = digitalRead(BUTTON);
  
  if((millis()- lastDebounceTime)>debounceDelay){
    if(reading != buttonState){
      buttonState = reading;

      if(buttonState == HIGH && !stav){
        stav= true;
        cas = LIMIT;
        previousMillis = millis();
        zobraz();
        //display.showNumberDec(cas,false);
      }
    }
  }
  lastButtonState = reading;


}
void zobraz(){
  String text =(cas<=10)?" "+String(--cas):String(--cas);
  lcd.setCursor(16-text.length(),1);
  lcd.clear();
  lcd.print(text);
  lcd.setCursor(0, 1); // move cursor to (2, 0)
  lcd.write((byte)0);
  lcd.setCursor(1, 1); // move cursor to (2, 0)
  lcd.write((byte)0);
  lcd.setCursor(2, 1); // move cursor to (2, 0)
  lcd.write((byte)0);
  
}