Analog Clock with LED Matrix and Arduino

/*
  Project:  Analog Clock with LED Matrix
  Author:   LAGSILVA
  Hardware: Arduino UNO R3 / LED Matrix with MAX72XX
  Date:     26.Jul.2017
  Revision: 1.1
  License:  CC BY-NC-ND 4.0
            (Attribution-NonCommercial-NoDerivatives 4.0 International)
*/

#include <LedControl.h>
#include <Time.h>
#include <TimeLib.h>

/*
  ***** Pin numbers for LedControl *****
  pin 10 is connected to the DataIn
  pin 08 is connected to the CLK
  pin 09 is connected to LOAD / CS
  We have only a single MAX72XX.
*/
LedControl lc = LedControl(10, 8, 9, 1);

byte xRef = 4; // Reference Row
byte yRef = 3; // Reference Collunm
byte mm1, mm5, hora, minuto;
byte ultMinuto = 10, ultHora = 10;
byte horaPin = 7, minutoPin = 6;
boolean ajustaHora = true, ajustaMinuto = true;
float pi = 3.1415927, xHH, yHH, xMM1, yMM1, xMM5, yMM5;


void setup() {

  pinMode(horaPin, INPUT_PULLUP);
  pinMode(minutoPin, INPUT_PULLUP);

  /* Wakeup call for MAX72XX */
  lc.shutdown(0, false);

  /* Set the brightness to a medium values */
  lc.setIntensity(0, 2);

}


void loop() {

  // Setup of Hours & Minutes
  ajustaHora = digitalRead(horaPin);
  ajustaMinuto = digitalRead(minutoPin);

  if (!ajustaHora) {
    adjustTime(3600);
  }

  if (!ajustaMinuto) {
    adjustTime(60);
  }

  hora = hour();
  minuto = minute();

  if (minuto != ultMinuto || hora != ultHora) {

    ultMinuto = minuto;
    ultHora = hora;
    lc.clearDisplay(0);

    // Minutes in steps of 5 (range of 0 to 55)
    mm5 = minuto / 5 * 5;

    //Minutes (1 to 4)
    mm1 = minuto % 5;

    // AM period
    if (hora >= 0 && hora <= 11) lc.setLed(0, xRef + 1, yRef, true);

    // PM period
    if (hora >= 12 && hora <= 23)lc.setLed(0, xRef - 1, yRef, true);

    // Coordinates for Hours & Minutes (steps of 5)
    xHH = round(-cos(hora * pi / 6) * 2) + xRef;
    yHH = round(sin(hora * pi / 6) * 2) + yRef;
    lc.setLed(0, xHH, yHH, true);

    xMM5 = round(-cos(mm5 * pi / 30) * 3.1) + xRef;
    yMM5 = round(sin(mm5 * pi / 30) * 3.1) + yRef;
    lc.setLed(0, xMM5, yMM5, true);

    //Coordinates for Minutes (1 to 4)
    yMM1 = yRef + 4;
    xMM1 = (mm1 - 1) * 2 + xRef - 3;
    if (mm1 > 0) lc.setLed(0, xMM1, yMM1, true);

  }

  // Center LED Blinking
  if (ajustaHora && ajustaMinuto) {
    lc.setLed(0, xRef, yRef, true);
    delay(200);
    lc.setLed(0, xRef, yRef, false);
    delay(800);
  }
  else delay(250);

}