单片机三个引脚控制16路流水灯

我们先来看下最终的效果

我们先用单片机按照74hc595手动分解的例子，来实现我们想要的结果。
首先，我们让16个led灯交叉亮起来

代码部分：

int stcp_pin = 4;
int shcp_pin = 6;
int ds_pin = 5; 


void setup ()
{
  pinmode(stcp_pin,output);
  pinmode(shcp_pin,output);
  pinmode(ds_pin,output); 
}

// 我们先让16个灯交叉亮
void loop()
{
  while(1)
  {
    digitalwrite(stcp_pin, low);
    
    // 1
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, low);
    digitalwrite(shcp_pin, high);
    // 2
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, high);
    digitalwrite(shcp_pin, high);
    // 3
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, low);
    digitalwrite(shcp_pin, high);
    // 4
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, high);
    digitalwrite(shcp_pin, high);
    // 5
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, low);
    digitalwrite(shcp_pin, high);
    // 6
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, high);
    digitalwrite(shcp_pin, high);
    
    // 7
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, low);
    digitalwrite(shcp_pin, high);
    // 8
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, high);
    digitalwrite(shcp_pin, high);
    // 9
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, low);
    digitalwrite(shcp_pin, high);
    // 10
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, high);
    digitalwrite(shcp_pin, high);
    // 11
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, low);
    digitalwrite(shcp_pin, high);
    // 12
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, high);
    digitalwrite(shcp_pin, high);
    
    // 13
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, low);
    digitalwrite(shcp_pin, high);
    // 14
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, high);
    digitalwrite(shcp_pin, high);
    // 15
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, low);
    digitalwrite(shcp_pin, high);
    // 16
    digitalwrite(shcp_pin, low);
    digitalwrite(ds_pin, high);
    digitalwrite(shcp_pin, high);
    
    digitalwrite(stcp_pin, high);    
  }
}

运行效果

然后我们再把代码简化一下，使其看起来更简洁，实用

int stcp_pin = 4;
int shcp_pin = 6;
int ds_pin = 5; 


void setup ()
{
  pinmode(stcp_pin,output);
  pinmode(shcp_pin,output);
  pinmode(ds_pin,output); 
  
  digitalwrite(stcp_pin, low);
}

void loop()
{
  unsigned char led_data;
  
  while(1)
  {
    
      led_data = 0xaa;
      // 第一个8位
      digitalwrite(stcp_pin, low); 
      for(int i=0; i<8; i++)
      {
        if(led_data&0x80){ digitalwrite(ds_pin, high);}
        else             { digitalwrite(ds_pin, low); }

        digitalwrite(shcp_pin, low);
        digitalwrite(shcp_pin, high);
        led_data <<=1;
      } 
    
      // 第二个8位
      led_data = 0xaa;
      for(int i=0; i<8; i++)
      {
        if(led_data&0x80){ digitalwrite(ds_pin, high);}
        else             { digitalwrite(ds_pin, low); }

        digitalwrite(shcp_pin, low);
        digitalwrite(shcp_pin, high);
        led_data <<=1;
      } 

      digitalwrite(stcp_pin, high); 

    delay(1000);
  }
}

我们稍微改变下，让led灯按照我们的意思工作，封装一下函数，然后让中间四个灯亮起来

int stcp_pin = 4;
int shcp_pin = 6;
int ds_pin = 5; 

void hc595_write(unsigned char data1, unsigned char data2);

void setup ()
{
  pinmode(stcp_pin,output);
  pinmode(shcp_pin,output);
  pinmode(ds_pin,output); 

}

void loop()
{
  unsigned char led_data1 = 0x03;
  unsigned char led_data2 = 0xc0;
  while(1)
  {
    hc595_write(led_data1, led_data2);
    delay(1000);
  }
}

void hc595_write(unsigned char data1, unsigned char data2)
{       
      // 第一个8位
      digitalwrite(stcp_pin, low); 
      for(int i=0; i<8; i++)
      {
        if(data1&0x80){ digitalwrite(ds_pin, high);}
        else             { digitalwrite(ds_pin, low); }

        digitalwrite(shcp_pin, low);
        digitalwrite(shcp_pin, high);
        data1 <<=1;
      } 
    
      // 第二个8位
      for(int i=0; i<8; i++)
      {
        if(data2&0x80){ digitalwrite(ds_pin, high);}
        else             { digitalwrite(ds_pin, low); }

        digitalwrite(shcp_pin, low);
        digitalwrite(shcp_pin, high);
        data2 <<=1;
      } 

      digitalwrite(stcp_pin, high); 
}

中间四个led灯亮的效果

然后我们连贯起来搞个流水的灯玩玩

int stcp_pin = 4;
int shcp_pin = 6;
int ds_pin = 5; 

unsigned char led_data1[8] = { 0x01, 0x02, 0x04, 0x08,
                               0x10, 0x20, 0x40, 0x80};
unsigned char led_data2[8] = { 0x01, 0x02, 0x04, 0x08,
                               0x10, 0x20, 0x40, 0x80};

void hc595_write(unsigned char data1, unsigned char data2);

void setup ()
{
  pinmode(stcp_pin,output);
  pinmode(shcp_pin,output);
  pinmode(ds_pin,output); 

}

void loop()
{

  while(1)
  {
    for(int i=0; i<8; i++)
    {
        hc595_write(0x00, led_data1[i]);
        delay(1000);
    }
    
    for(int i=0; i<8; i++)
    {
        hc595_write( led_data2[i], 0x00);
        delay(1000);
    }
  }
}

void hc595_write(unsigned char data1, unsigned char data2)
{       
      // 第一个8位
      digitalwrite(stcp_pin, low); 
      for(int i=0; i<8; i++)
      {
        if(data1&0x80){ digitalwrite(ds_pin, high);}
        else             { digitalwrite(ds_pin, low); }

        digitalwrite(shcp_pin, low);
        digitalwrite(shcp_pin, high);
        data1 <<=1;
      } 
    
      // 第二个8位
      for(int i=0; i<8; i++)
      {
        if(data2&0x80){ digitalwrite(ds_pin, high);}
        else             { digitalwrite(ds_pin, low); }

        digitalwrite(shcp_pin, low);
        digitalwrite(shcp_pin, high);
        data2 <<=1;
      } 

      digitalwrite(stcp_pin, high); 
}

最终的流水灯实验效果


当然arduino本身自带了移位函数，同样可以达到效果

int stcp_pin = 4;
int shcp_pin = 6;
int ds_pin = 5; 

unsigned char led_data1[8] = { 0x01, 0x02, 0x04, 0x08,
                               0x10, 0x20, 0x40, 0x80};
unsigned char led_data2[8] = { 0x01, 0x02, 0x04, 0x08,
                               0x10, 0x20, 0x40, 0x80};

void setup ()
{
  pinmode(stcp_pin,output);
  pinmode(shcp_pin,output);
  pinmode(ds_pin,output); 
}
void loop()
{
  for(int a=0; a<8; a++)   
  {
    digitalwrite(stcp_pin,low); 
    shiftout(ds_pin,shcp_pin,msbfirst,led_data1[a]);
    shiftout(ds_pin,shcp_pin,msbfirst,0x00);
    digitalwrite(stcp_pin,high); 
    delay(500); 
  }
  
  for(int a=0; a<8; a++)   
  {
    digitalwrite(stcp_pin,low); 
    shiftout(ds_pin,shcp_pin,msbfirst,0x00);
    shiftout(ds_pin,shcp_pin,msbfirst,led_data2[a]);
    digitalwrite(stcp_pin,high); 
    delay(500); 
  }
}

流水的延时500ms的效果

总结：

1、复杂的功能，深入分解后背后的原理其实还是挺简单的；

2、我们绝大部分时候都在造“*“，殊不知更优秀的“*”已经造好了；知晓“*”的由来，然后造出更优秀的“*”给自己用也是单片机学习路上的一项重要技能。