#include <LiquidCrystal_I2C.h>

#define BUTTON 5
#define LIMIT 10

unsigned long previousMillis = 0;

boolean stav = true;

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

LiquidCrystal_I2C lcd(0x27, 16, 2);
uint8_t cas = LIMIT;

void setup() {
  // put your setup code here, to run once:
  pinMode(BUTTON, INPUT);
  tone(4,262,500);
  lcd.init(); //inicializuje
  lcd.backlight(); //nastavi podsvietenie
  
}

void loop() {
  
  unsigned long currentMillis = millis();
  if(currentMillis - previousMillis >=1000 && stav){
      previousMillis = currentMillis;
      cas--;
      zobraz();
      if(cas == 0){
        tone(4,262,200);
        stav = false;
      }
  }

  int reading = digitalRead(BUTTON);

      if(reading != lastButtonState) {
        lastDebounceTime = millis();
  }

      if((millis() - lastDebounceTime) > debounceDelay) {

        if(reading != buttonState) {
          buttonState = reading;
      
            if(buttonState == HIGH && !stav) {
            stav = true;
            cas = LIMIT;
            previousMillis = millis();
           zobraz();
        } 
        else if(buttonState == HIGH && stav){
          tone(4,292);
          delay(100);
          tone(4,192,200);
          stav = false;
        }
      }
    }
      lastButtonState  = reading;




}
void zobraz()
{
  lcd.setCursor(7,1);
  String text = (cas<10)? String(cas) : String(cas);
  lcd.print(cas);
}