搞单片机怎少得了流水灯，所以其它的一切都先暂时放一边，开篇就来个流水灯（共阳极 8 位）。

主函数及相关引用：

#include "REGX52.H"
#include "math.h"
#include "intrins.h"
#define craftour_com P0

void delay(unsigned int ms)
{
    ms *= 3600;
    while(--ms);
}

/*craftour()*/

void main()
{ 
    while(1)
    {
        craftour_com = 0x00;
        delay(1000);
        goto begin;
        craftour(-1.0, craftour_com);
        
        begin:
        craftour_com = 0xFE;//第一颗
        delay(1000);
        craftour(0.0, craftour_com);
        
        craftour_com = 0xFD;//第二颗
        delay(1000);
        craftour(1.0, craftour_com);

        craftour_com = 0xFB;
        delay(1000);
        craftour(2.0, craftour_com);
        
        craftour_com = 0xF7;
        delay(1000);
        craftour(3.0, craftour_com);
        
        craftour_com = 0xEF;
        delay(1000);
        craftour(4.0, craftour_com);
        
        craftour_com = 0xDF;
        delay(1000);
        craftour(5.0, craftour_com);
        
        craftour_com = 0xBF;
        delay(1000);
        craftour(6.0, craftour_com);
        
        craftour_com = 0x7F;
        delay(1000);
        craftour(7.0, craftour_com);
    }
}

核心函数：

void craftour(double index, unsigned char seed)
{
    unsigned char flag = 0; 
    unsigned int offset = 0;
    unsigned char x = 0, temp = seed; double y = 0, i = index;
    while(offset < 8)
    {
        craftour_com = seed ^ flag;

        if((i + 1) > 7)
        {
            x = pow(2, y) + 1; y++;            
            flag = (unsigned char)(pow(2, (offset + 1)) - x);
        }
        else
        {
            flag = (unsigned char)(pow(2, (offset + 1)) - 1);
        }
        
        index++; i++;
        if(index >= 8)
        {
            index = 0;
        }

        seed <<= 1;
        
        craftour_com = temp;
        delay(300);
        offset++;
    }
    craftour_com = 0xFF;//全灭
    delay(3000);
}

原理图：