/*
  程序： 联合体+结构体+位域 演示程序
  公众号：孤独的二进制
  日期：2022-05-06
*/

#define DATAPIN 2
#define CLOCKPIN 3
#define LATCHPIN 4

void setup()
{
  Serial.begin(9600);

  pinMode(DATAPIN, OUTPUT);
  pinMode(CLOCKPIN, OUTPUT);
  pinMode(LATCHPIN, OUTPUT);

  //demo1();
  demo2();

}

void demo1() {
  byte data = 255;
  shiftOut(DATAPIN, CLOCKPIN, MSBFIRST, data);
  digitalWrite(LATCHPIN, HIGH);
  digitalWrite(LATCHPIN, LOW);
}

void demo2() {
  //联合体+结构体+位域
  union LED {  
    byte all;  
    struct {  
      byte led0: 1;
      byte led1: 1;
      byte led2: 1;
      byte led3: 1;
      byte led4: 1;
      byte led5: 1;
      byte led6: 1;
      byte led7: 1;
    } group;
  };

  LED led;
  led.all = 0;

  led.group.led0 = 1;

  Serial.print("led memory size : ");
  Serial.print(sizeof(led));
  Serial.println(" byte");

  shiftOut(DATAPIN, CLOCKPIN, MSBFIRST, led.all);
  digitalWrite(LATCHPIN, HIGH);
  digitalWrite(LATCHPIN, LOW);
}

void loop()
{

}
74HC595