Thank you for your reply but could then tell me what to change in this code, for example, please 
Because I’ve already tried to change the MAX_DEVICES setting and stuff but that doesn’t change anything…
// Use the MD_MAX72XX library to display a Pacman animation
// Just for fun!
#include <MD_MAX72xx.h>
#include <SPI.h>
#define DEBUG 0Â // Enable or disable (default) debugging output
#if DEBUG
#define PRINT(s, v)Â { Serial.print(F(s)); Serial.print(v); }Â Â Â // Print a string followed by a value (decimal)
#define PRINTX(s, v)Â { Serial.print(F(s)); Serial.print(v, HEX); } // Print a string followed by a value (hex)
#define PRINTB(s, v)Â { Serial.print(F(s)); Serial.print(v, BIN); } // Print a string followed by a value (binary)
#define PRINTC(s, v)Â { Serial.print(F(s)); Serial.print((char)v); }Â // Print a string followed by a value (char)
#define PRINTS(s)Â Â { Serial.print(F(s)); }Â Â Â Â Â Â Â Â Â Â Â // Print a string
#else
#define PRINT(s, v)Â // Print a string followed by a value (decimal)
#define PRINTX(s, v)Â // Print a string followed by a value (hex)
#define PRINTB(s, v)Â // Print a string followed by a value (binary)
#define PRINTC(s, v)Â // Print a string followed by a value (char)
#define PRINTS(s)Â Â // Print a string
#endif
// --------------------
// MD_MAX72xx hardware definitions and object
// Define the number of devices we have in the chain and the hardware interface
// NOTE: These pin numbers will probably not work with your hardware and may
// need to be adapted
//
#define HARDWARE_TYPE MD_MAX72XX::PAROLA_HW
#define MAX_DEVICES 4
#define CLK_PINÂ 13Â // or SCK
#define DATA_PINÂ 11Â // or MOSI
#define CS_PINÂ Â 10Â // or SS
MD_MAX72XX mx = MD_MAX72XX(HARDWARE_TYPE, CS_PIN, MAX_DEVICES);Â Â Â Â Â Â Â Â Â Â Â // SPI hardware interface
//MD_MAX72XX mx = MD_MAX72XX(HARDWARE_TYPE, DATA_PIN, CLK_PIN, CS_PIN, MAX_DEVICES); // Arbitrary pins
// --------------------
// Constant parameters
//
#define ANIMATION_DELAY 75 // milliseconds
#define MAX_FRAMESÂ Â Â 4Â // number of animation frames
// ========== General Variables ===========
//
const uint8_t pacman[MAX_FRAMES][18] =Â // ghost pursued by a pacman
{
 { 0xfe, 0x73, 0xfb, 0x7f, 0xf3, 0x7b, 0xfe, 0x00, 0x00, 0x00, 0x3c, 0x7e, 0x7e, 0xff, 0xe7, 0xc3, 0x81, 0x00 },
 { 0xfe, 0x7b, 0xf3, 0x7f, 0xfb, 0x73, 0xfe, 0x00, 0x00, 0x00, 0x3c, 0x7e, 0xff, 0xff, 0xe7, 0xe7, 0x42, 0x00 },
 { 0xfe, 0x73, 0xfb, 0x7f, 0xf3, 0x7b, 0xfe, 0x00, 0x00, 0x00, 0x3c, 0x7e, 0xff, 0xff, 0xff, 0xe7, 0x66, 0x24 },
 { 0xfe, 0x7b, 0xf3, 0x7f, 0xf3, 0x7b, 0xfe, 0x00, 0x00, 0x00, 0x3c, 0x7e, 0xff, 0xff, 0xff, 0xff, 0x7e, 0x3c },
};
const uint8_t DATA_WIDTH = (sizeof(pacman[0])/sizeof(pacman[0][0]));
uint32_t prevTimeAnim = 0;Â // remember the millis() value in animations
int16_t idx;Â Â Â Â Â Â Â Â // display index (column)
uint8_t frame;Â Â Â Â Â Â Â // current animation frame
uint8_t deltaFrame;Â Â Â Â // the animation frame offset for the next frame
// ========== Control routines ===========
//
void resetMatrix(void)
{
 mx.control(MD_MAX72XX::INTENSITY, MAX_INTENSITY/2);
 mx.control(MD_MAX72XX::UPDATE, MD_MAX72XX::ON);
 mx.clear();
}
void setup()
{
 mx.begin();
 resetMatrix();
 prevTimeAnim = millis();
 #if DEBUG
 Serial.begin(57600);
 #endif
 PRINTS("\n[MD_MAX72XX Pacman]");
}
void loop(void)
{
 static boolean bInit = true; // initialise the animation
 // Is it time to animate?
 if (millis()-prevTimeAnim < ANIMATION_DELAY)
  return;
 prevTimeAnim = millis();   // starting point for next time
 mx.control(MD_MAX72XX::UPDATE, MD_MAX72XX::OFF);
 // Initialize
 if (bInit)
 {
  mx.clear();
  idx = -DATA_WIDTH;
  frame = 0;
  deltaFrame = 1;
  bInit = false;
  // Lay out the dots
  for (uint8_t i=0; i<MAX_DEVICES; i++)
  {
   mx.setPoint(3, (i*COL_SIZE) + 3, true);
   mx.setPoint(4, (i*COL_SIZE) + 3, true);
   mx.setPoint(3, (i*COL_SIZE) + 4, true);
   mx.setPoint(4, (i*COL_SIZE) + 4, true);
  }
 }
 // now run the animation
 PRINT("\nINV I:", idx);
 PRINT(" frame ", frame);
 // clear old graphic
 for (uint8_t i=0; i<DATA_WIDTH; i++)
  mx.setColumn(idx-DATA_WIDTH+i, 0);
 // move reference column and draw new graphic
 idx++;
 for (uint8_t i=0; i<DATA_WIDTH; i++)
  mx.setColumn(idx-DATA_WIDTH+i, pacman[frame][i]);
 // advance the animation frame
 frame += deltaFrame;
 if (frame == 0 || frame == MAX_FRAMES-1)
  deltaFrame = -deltaFrame;
 // check if we are completed and set initialise for next time around
 bInit = (idx == mx.getColumnCount()+DATA_WIDTH);
 mx.control(MD_MAX72XX::UPDATE, MD_MAX72XX::ON);
 return;
}