// 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 "AEPL.h"

// MAX7219 Control registers

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


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.
}

int c = 0;
uint8_t sequence[5] = { 0, 3, 3, 2, 1 };

void loop()  {
  uint8_t symbolIndex = sequence[c++];
  if(c == 5)
    c = 0;

  uint8_t* symbol = IMAGES[symbolIndex];

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

  delay(1000);
}