// original code 
// https://projecthub.arduino.cc/mdraber/controlling-8x8-dot-matrix-with-max7219-and-arduino-0c417a

#include <SPI.h>
#define CS 7

#include "Helpers.h"
#include "Symbols.h"

// MAX7219 Control registers

#define DECODE_MODE   9
#define INTENSITY     0x0A
#define SCAN_LIMIT    0x0B
#define SHUTDOWN      0x0C
#define DISPLAY_TEST  0x0F

int c = 0;

void SendData(uint8_t address, uint8_t value) {
  digitalWrite(CS, LOW);        // Start transfer, select chip
  SPI.transfer(address);        // Send address.
  SPI.transfer(reverse[value]); // Send the value.
  digitalWrite(CS, HIGH);       // Finish transfer, unselect chip
}

void setup()   {
  pinMode(CS, OUTPUT);
  SPI.setBitOrder(MSBFIRST);        // Most significant   bit first
  SPI.begin();                      // Start SPI
  SendData(DISPLAY_TEST,  0x01);    // Run test - All LED segments lit.
  delay(1000);
  SendData(DISPLAY_TEST,  0x00);    // Finish test mode.
  SendData(DECODE_MODE,   0x00);    // Disable BCD mode.
  SendData(INTENSITY,     0x0e);    // Use lowest intensity.
  SendData(SCAN_LIMIT,    0x0f);    // Scan all digits.
  SendData(SHUTDOWN,      0x01);    // Turn on chip.
}

void SendSymbol(uint8_t symbolIndex)
{
  uint8_t* symbol = SYMBOLS[symbolIndex];

  for (int i = 1; i < 9; i++)
    SendData(i, symbol[i - 1]);
}

void SendSequence(uint8_t* seq)
{
  uint8_t symbolIndex = seq[c++];
  if (c == sizeof(seq))
    c = 0;

  SendSymbol(symbolIndex);
}

//uint8_t sequence[] = { 0,1,2,3,4,5,6,7,8,9 };           // all digits
//uint8_t sequence[] = { 10,11,12, /* ... */ 33,34,35 };  // upper case ABCXYZ
//uint8_t sequence[] = { 37,38,39, /* ... */ 60,61,62 };  // upper case abcxyz

//                      a, p, p, l, e, SPC, Y, u, m,  SPC
uint8_t sequence[] = { 10,52,52,48,41, 36, 34,58,49,  36}; // Apple Yum ....

void loop()  {
  SendSequence(sequence);
  delay(1000);
}