// L1-016 8位二进制计数灯 教师完整版
// 位权：128、64、32、16、8、4、2、1
int b128 = 13;
int b64  = 12;
int b32  = 11;
int b16  = 10;
int b8   = 9;
int b4   = 8;
int b2   = 7;
int b1   = 6;

int count = 0;

void setup()
{
  pinMode(b128, OUTPUT);
  pinMode(b64,  OUTPUT);
  pinMode(b32,  OUTPUT);
  pinMode(b16,  OUTPUT);
  pinMode(b8,   OUTPUT);
  pinMode(b4,   OUTPUT);
  pinMode(b2,   OUTPUT);
  pinMode(b1,   OUTPUT);
}

void loop()
{
  // 逐位解码：低位取余、高位整除剥离
  digitalWrite(b1,  (count % 2 == 1) ? HIGH : LOW);
  digitalWrite(b2,  ((count / 2)  % 2 == 1) ? HIGH : LOW);
  digitalWrite(b4,  ((count / 4)  % 2 == 1) ? HIGH : LOW);
  digitalWrite(b8,  ((count / 8)  % 2 == 1) ? HIGH : LOW);
  digitalWrite(b16, ((count / 16) % 2 == 1) ? HIGH : LOW);
  digitalWrite(b32, ((count / 32) % 2 == 1) ? HIGH : LOW);
  digitalWrite(b64, ((count / 64) % 2 == 1) ? HIGH : LOW);
  digitalWrite(b128,((count / 128)% 2 == 1) ? HIGH : LOW);

  delay(150);

  count++;

  // 8位二进制溢出归零
  if(count > 255)
  {
    count = 0;
  }
}