Arrow Snippet - Multiple LED Matrix control from Arduino

gistfile1.txt

const int clockPin = 12;
const int latchPin = 11;
const int dataPin1 = 7;
const int dataPin2 = 6;
const int dataPin3 = 5;

byte displayBuffer[24]= {0x18,0x3C,0x66,0xDB,0x18,0x18,0x18,0x18, 0x18,0x3C,0x66,0xDB,0x18,0x18,0x18,0x18, 0x18,0x3C,0x66,0xDB,0x18,0x18,0x18,0x18};

void setup() {
  pinMode(clockPin, OUTPUT);
  pinMode(latchPin, OUTPUT);
  pinMode(dataPin1, OUTPUT);
  pinMode(dataPin2, OUTPUT);
  pinMode(dataPin3, OUTPUT);
}

void loop() {
  drawImage(displayBuffer);
}

void drawImage(byte * matrix) {
  
  // Draw each column of the buffer, one by one.
  for(int i=0; i<8; i++) {
    
    // Shift out the position of the column, active high values.
    for(int j=0; j<8; j++) { 
      digitalWrite(clockPin, LOW);
      digitalWrite(dataPin1, (1<<i) & (1<<j) );
      digitalWrite(dataPin2, (1<<i) & (1<<j) );
      digitalWrite(dataPin3, (1<<i) & (1<<j) );
      digitalWrite(clockPin, HIGH);
    }
    
    // Shift out the position of the column, active low values.
    for(int j=0; j<8; j++) { 
      digitalWrite(clockPin, LOW);
      digitalWrite(dataPin1, (~(matrix[i+16])) & (1<<j) );
      digitalWrite(dataPin2, (~(matrix[i+8])) & (1<<j) );
      digitalWrite(dataPin3, (~(matrix[i])) & (1<<j) );
      digitalWrite(clockPin, HIGH);
    }
  
    // Toggle latch pin to display sent data.
    digitalWrite(latchPin,LOW);
    digitalWrite(latchPin,HIGH);
  } 
}