#define CLK 13
#define DIN 11
#define CS  10
#define X_SEGMENTS   4  //??????
#define Y_SEGMENTS   2
#define NUM_SEGMENTS (X_SEGMENTS * Y_SEGMENTS)
 
// a framebuffer to hold the state of the entire matrix of LEDs
// laid out in raster order, with (0, 0) at the top-left
byte fb[8 * NUM_SEGMENTS];
 
 
void shiftAll(byte send_to_address, byte send_this_data)
{
  //start communication
  digitalWrite(CS, LOW);
  for (int i = 0; i < NUM_SEGMENTS; i++) {
    //send an address and the data
    shiftOut(DIN, CLK, MSBFIRST, send_to_address);
    shiftOut(DIN, CLK, MSBFIRST, send_this_data);
  }
  digitalWrite(CS, HIGH);
}
 
 
void setup() {
  Serial.begin(115200);
  pinMode(CLK, OUTPUT);
  pinMode(DIN, OUTPUT);
  pinMode(CS, OUTPUT);
 
  // Setup each MAX7219
  shiftAll(0x0f, 0x00); //display test register - test mode off
  shiftAll(0x0b, 0x07); //scan limit register - display digits 0 thru 7
  shiftAll(0x0c, 0x01); //shutdown register - normal operation
  shiftAll(0x0a, 0x0f); //intensity register - max brightness
  shiftAll(0x09, 0x00); //decode mode register - No decode
}
 
void show() {
  for (byte row = 0; row < 8; row++) {
    digitalWrite(CS, LOW);
    byte segment = NUM_SEGMENTS;  
    while (segment--) {

      //compute row and column
      byte x = segment % X_SEGMENTS;
      byte y = segment / X_SEGMENTS * 8;

      //compute address given the above
      byte addr = (row + y) * X_SEGMENTS;
 
      // odd rows of segments
      if (segment & X_SEGMENTS) { 
        shiftOut(DIN, CLK, MSBFIRST, 8 - row);    //?????
        shiftOut(DIN, CLK, LSBFIRST, fb[addr + x]);
      } else { 

        
        shiftOut(DIN, CLK, MSBFIRST, 1 + row);
        shiftOut(DIN, CLK, MSBFIRST, fb[addr - x + X_SEGMENTS - 1]);
      }
    
    }
    digitalWrite(CS, HIGH);
  }
}
 
void loop(){
  for(int i=0; i<64; i++) fb[i]=0;
 
  // fb[(millis()/1000)%64] = (1<<(millis()/125%8)); // inlocuiti asta cu fb[0]=B00000011;  fb[63] = 255;
  fb[0]=B00000011;
  fb[63] = B00000001;
  show();
}