Matrix.ino

int row[] = {2, 3, 4, 5, 6, 7, 8, 9};
int column[] = {10, 11, 12, 13, A0, A1, A2, A3};

//int buffer[8][8];

int lastRow;
int lastColumn;

void setup() {
  // put your setup code here, to run once:
  for (int i = 0; i < 8; i++) {
    pinMode(row[i], OUTPUT);
    rowSet(i, LOW);
    pinMode(column[i], OUTPUT);
    columnSet(i, LOW);
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  for (int i = 0; i < 8; i++) {
    rowSet(lastRow, LOW);
    rowSet(i, HIGH);
    for (int j = 0; j < 8; j++) {
      columnSet(j, HIGH);
      delay(50);
      lastColumn = j;
      columnSet(lastColumn, LOW);
    }
    lastRow = i;
  }



}

void matrix() {
  for (int i = 0; i < 8; i++) {
    for (int j = 0; j < 8; j++) {
      //buffer[i][j]
    }
  }
}

void rowSet(int index, boolean state) {
  digitalWrite(row[index], state);
}

void columnSet(int index, boolean state) {
  if (index > 3) {
    analogWrite(column[index], state == HIGH ? 0 : 1024);
  } else {
    digitalWrite(column[index], !state);
  }
}