// Dip switch pins
const int dipSwitchPin[] = {53};

// First dipswitch's button state (cannot be constant - needs to be changed)
int buttonState[] = {0};

// Row and column pins (rows - cathode, columns, anode)
const int rows[] = {17, 16, 15, 14, 2, 3, 4, 5};
const int cols[] = {6, 7, 8, 9, 10, 11, 12, 13};


// Unsigned to ensure that negative values CANNOT be stored in said array
unsigned int initialArray[8][8] =
{
  {0,0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0,0}
};

// This array is basically the character array. Top to bottom 0 - 9, A - F
const unsigned int hexadecimalArray[16][8][8] =
{
  {{0,1,1,1,1,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,1,1,1,1,0,0}},
  {{0,0,0,1,0,0,0,0},{0,0,1,1,0,0,0,0},{0,1,0,1,0,0,0,0},{0,0,0,1,0,0,0,0},{0,0,0,1,0,0,0,0},{0,0,0,1,0,0,0,0},{0,0,0,1,0,0,0,0},{0,1,1,1,1,1,0,0}},
  {{0,1,1,1,1,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0},{0,1,1,1,1,1,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,1,1,1,1,0,0}},
  {{0,1,1,1,1,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0},{0,1,1,1,1,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0},{0,1,1,1,1,1,0,0}},
  {{0,0,0,0,1,0,0,0},{0,0,0,1,1,0,0,0},{0,0,1,0,1,0,0,0},{0,1,0,0,1,0,0,0},{1,1,1,1,1,1,0,0},{0,0,0,0,1,0,0,0},{0,0,0,0,1,0,0,0},{0,0,0,0,1,0,0,0}},
  {{0,1,1,1,1,1,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,1,1,1,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0},{0,1,1,1,1,1,0,0}},
  {{0,1,1,1,1,1,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,1,1,1,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,1,1,1,1,0,0}},
  {{0,1,1,1,1,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0}},
  {{0,1,1,1,1,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,1,1,1,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,1,1,1,1,0,0}},
  {{0,1,1,1,1,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,1,1,1,1,0,0},{0,0,0,0,0,1,0,0},{0,0,0,0,0,1,0,0},{0,1,1,1,1,1,0,0}},
  {{0,1,1,1,1,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,1,1,1,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0}},
  {{0,1,1,1,1,0,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,1,1,1,0,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,1,1,1,0,0,0}},
  {{0,1,1,1,1,1,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,1,1,1,1,0,0}},
  {{0,1,1,1,1,0,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,0,0,0,1,0,0},{0,1,1,1,1,0,0,0}},
  {{0,1,1,1,1,1,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,1,1,1,1,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,1,1,1,1,0,0}},
  {{0,1,1,1,1,1,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,1,1,1,1,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0},{0,1,0,0,0,0,0,0}}
};

void setup() 
{ 
  // Initiate dipswitch pin to receive input
  pinMode(dipSwitchPin[0], INPUT_PULLUP);  

  // Cathodes: HIGH voltage, Anodes: LOW voltage With this combination, voltage- 
  // difference across LEDs is insignificant, higher voltage at anode than cathode- 
  // is required for forward biasing LEDs to emit light.
  for (int j = 0; j < 8; j++)
  {
    pinMode(rows[j], OUTPUT);
    digitalWrite(rows[j], HIGH);  

    pinMode(cols[j], OUTPUT);
    digitalWrite(cols[j], LOW);   
  }
}

void loop() 
{ 
  bool displayFlag = false;
  
  buttonState[0] = digitalRead(dipSwitchPin[0]);

  // Verify that first button on dipswitch is turned on, setting display character flag as true
  if (buttonState[0] == LOW) 
  {
    displayFlag = !displayFlag; 
  }

  // If first button pressed, every single element in initial array will be replaced by elements in hexadecimal array, to allow for showcasing of character
  if (displayFlag)
  {
    for (int characterNum = 0; characterNum < 16; characterNum++)
    {
      for (int k = 0; k < 8; k++)
      {
        for (int l = 0; l < 8; l++)
        { 
          initialArray[k][l] = hexadecimalArray[characterNum][k][l];
        }
      }

      unsigned long startTime = millis();

      // Display the current character for 2 seconds
      while (millis() - startTime < 2000)
      {
        // If first button is pressed again (turned off), break while loop to switch off all LEDs
        buttonState[0] = digitalRead(dipSwitchPin[0]);
        if (buttonState[0] == HIGH) 
        { 
          displayFlag = false;
          break;
        }

        for (int m = 0; m < 8; m++)
        {
          digitalWrite(rows[m], LOW); // Setting cathode rows low to create p.d between cathode and anode to allow current flow
          for (int n = 0; n < 8; n++)
          {
            digitalWrite(cols[n], initialArray[m][n]);
            digitalWrite(cols[n], LOW);
          }
          digitalWrite(rows[m], HIGH); // Turning off row currents to prevent forwarding of lit leds from previous character to next
        }
      }
    }
  }
  else  // displayFlag is false, set current character to 0 and turn off all LEDs
  {
    for (int o = 0; o < 8; o++) 
    {
      for (int p = 0; p < 8; p++) 
      {
        initialArray[o][p] = hexadecimalArray[1][o][p];
      }
    }
    for (int q = 0; q < 8; q++)
    {
      digitalWrite(rows[q], HIGH); // Set rows (cathodes) to HIGH
    }

    for (int r = 0; r < 8; r++)
    {
      digitalWrite(cols[r], LOW); // Set columns (anodes) to LOW
    }
  }
}