// Binary clock for a 4x4 LED matrix

#include <Time.h>

uint8_t columns[4] = {13,12,11,10};
uint8_t rows[4] = {9,8,7,6};
uint8_t matrix[4][4] = {
  { 0, 0, 0, 0 },
  { 0, 0, 0, 0 },
  { 0, 0, 0, 0 },
  { 0, 0, 0, 0 }
};

void setup() {
  // Init the output pins
  for (int i = 0; i < 4; i++) {
    pinMode(rows[i], OUTPUT);
  }
  for (int i = 0; i < 4; i++) {
    pinMode(columns[i], OUTPUT);
  }

 setClock(17,12); // Set the current time here

}

void loop() {

 setMatrix(); // Sets the matrix arrays to the current time in binary
 showMatrix(); // Does the multiplexing for the LED matrix

}

void showMatrix() {
 // Parse all rows
 for (int x = 0; x < 4; x++) {
   // Set previous row to 0 and
   // matrix value on the corresponding pin
   for (int y = 0; y < 4; y++) {
     digitalWrite(rows[y], !matrix[x][y]);
   }
   // Set current column to 1
   digitalWrite(columns[x], 1);
   delay(1);
   // Delete current column
   digitalWrite(columns[x], 0);
 }

}

void setMatrix() {

  int munit = minute()%10; //sets the variable munit and hunit for the unit digits
  int hunit = hour()%10;

   //minutes units
  if(munit == 1 || munit == 3 || munit == 5 || munit == 7 || munit == 9) { matrix[3][3] = 1; } else { matrix[3][3] = 0; }
  if(munit == 2 || munit == 3 || munit == 6 || munit == 7) { matrix[2][3] = 1; } else { matrix[2][3] = 0; }
  if(munit == 4 || munit == 5 || munit == 6 || munit == 7) { matrix[1][3] = 1; } else { matrix[1][3] = 0; }
  if(munit == 8 || munit == 9) { matrix[0][3] = 1;} else { matrix[0][3] = 0; }

  //minutes
  if((minute() >= 10 && minute() < 20) || (minute() >= 30 && minute() < 40) || (minute() >= 50 && minute() < 60))  { matrix[3][2] = 1; } else {matrix[3][2] = 0;}
  if(minute() >= 20 && minute() < 40)  {matrix[2][2] = 1;} else {matrix[2][2] = 0;}
  if(minute() >= 40 && minute() < 60) {matrix[1][2] = 1;} else {matrix[1][2] = 0;}

  //hour units
  if(hunit == 1 || hunit == 3 || hunit == 5 || hunit == 7 || hunit == 9) {matrix[3][1] = 1;} else {matrix[3][1] = 0;}
  if(hunit == 2 || hunit == 3 || hunit == 6 || hunit == 7) {matrix[2][1] = 1;} else {matrix[2][1] = 0;}
  if(hunit == 4 || hunit == 5 || hunit == 6 || hunit == 7) {matrix[1][1] = 1;} else {matrix[1][1] = 0;}
  if(hunit == 8 || hunit == 9) {matrix[0][1] = 1;} else {matrix[0][1] = 0;}

  //hour
  if(hour() >= 10 && hour() < 20)  {matrix[3][0] = 1;} else {matrix[3][0] = 0;}
  if(hour() >= 20 && hour() < 24)  {matrix[2][0] = 1;} else {matrix[2][0] = 0;}

}

void setClock(int hour, int minute) { // Helper method to set time more easily (seconds and date can be ignored for this program).

  setTime(hour,minute,00,00,00,2000);

}