matrix_via_shift_reg.c

#define SHIFT_DATA 8
#define SHIFT_CLK  9
#define SHIFT_OUT 10
#define LED 13
#define PATTERN 0x5555

unsigned int image[] = {
   0x55AA,
   0xAA55,
   0x55AA,
   0xAA55,
   0x55AA,
   0xAA55,
   0x55AA,
   0xAA55
};

void setup() {
  pinMode(SHIFT_DATA, OUTPUT);
  pinMode(SHIFT_CLK, OUTPUT);
  pinMode(SHIFT_OUT, OUTPUT);  
  pinMode(LED, OUTPUT);
  digitalWrite(SHIFT_CLK, LOW);
  digitalWrite(SHIFT_OUT, LOW);
  
}

void loop() {
  int row, i;
  int on = 1;
  for(row = 0;row<8; row++) {
    digitalWrite(LED, on);                                                                                                                                                                                           
    on = !on;
    for(i=0;i<16;i++) {
      digitalWrite(SHIFT_DATA, (image[row]>> i) & 1);
      digitalWrite(SHIFT_CLK, HIGH);
      digitalWrite(SHIFT_CLK, LOW);
 
    }
    //digitalWrite(LED, LOW);
    for(i=0;i<8;i++) {
      if (i == row) {
        digitalWrite(SHIFT_DATA, LOW);
      } else {
        digitalWrite(SHIFT_DATA, HIGH);
      }
      digitalWrite(SHIFT_CLK, HIGH);
      digitalWrite(SHIFT_CLK, LOW);
    }   
    digitalWrite(SHIFT_OUT, HIGH);
    digitalWrite(SHIFT_OUT, LOW);
  }
}