#include "RTClib.h"
#include <Wire.h>

#define cln_pin 6

static RTC_DS1307 RTC;

const unsigned int digits[10] = {126, 48, 109, 121, 51, 91, 95, 112, 127, 123}; //nebo lze zapsat nula jako 0b1111110
const unsigned int digit_pins[4] = {2, 3, 4, 5};
const unsigned int leds[7] = {7, 8, 9, 10, 11, 12, 13};

void setup() {
  for (int i = 2; i < 14; i++) {
    pinMode(i, OUTPUT);
    digitalWrite(i, LOW);
  }
  Serial.begin(9600);
  RTC.begin();

  char a[] = {__TIME__};
  a[1] = char(int(a[1]) +1);
  RTC.adjust(DateTime(__DATE__, a));
  //RTC.setHourMode(CLOCK_H24);
}

void loop() {
  DateTime TimeNow = RTC.now();
  int num_to_display = TimeNow.hour()*100 + TimeNow.minute();
  //num_to_display = byte(num_to_display);
  //Serial.println(num_to_display);
  
  for (int i = 3; i >= 0; i--) {
    display_digit(num_to_display % 10, i);
    num_to_display = int(num_to_display / 10);
  }

  if (TimeNow.second() % 2 == 0) {
    digitalWrite(cln_pin, HIGH);
  }
  else {
    digitalWrite(cln_pin, LOW);
  }

}

void display_digit(int num, int dig) {
  num = digits[num];
  for (int i = 0; i < 7; i++) {
    digitalWrite(leds[6 - i], 1-((num >> i) & 1));
  }
  digitalWrite(digit_pins[dig], HIGH);
  delay(25);
  digitalWrite(digit_pins[dig], LOW);
}