//跳线设置:默认跳线位
#include <reg51.h>       
typedef unsigned char uchar;
#define Ton 40
#define LED P1
sbit leds=P1^4;
sbit LED0 = P1^0;
sbit LED1 = P1^1;
sbit LED2 = P1^2;
sbit LED3 = P1^3;
sbit LED4 = P1^4;
sbit LED5 = P1^5;
sbit LED6 = P1^6;
sbit LED7 = P1^7;
      
unsigned char Maikuan=0;
static unsigned char ledon[8] = {0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01};
uchar Occupy_led; //占空比越大，灯越亮
bit light;
uchar m;     
void Inittime()
      {
          TMOD = 0x02; //定时器0，工作方式2，自动重装
          TH0 = 256-Ton;
          TL0 = 256-Ton;
          ET0 = 1;
         EA = 1;
         TR0 = 1;
     }
//定时器0中断
     void time0() interrupt 1 using 0
      {
           Maikuan++;
      }
void main()
       {
          unsigned char i = 0,j = 0; //初始化i，j
    leds=0;
          Inittime();
         while (1)
           {
               //第1，3，5，7个灯半亮，其余的全亮。             
            for(i=254; i>0; i--)      
            {
                while ( Maikuan!=20)
                {
                        LED = 0x00;
                }
                while ( Maikuan!=200)
                {
                        LED = 0x55;
                }
   
               Maikuan = 0;
            }
 
   //最难的：8个灯从第一个开始依次渐亮，直到最后一个。再从最后一个起渐暗，直到第一个。如此循环往复。
   for(j = 0;j<=7;j++)
   {
    i = 0;      
    while(i!=255)     // 由暗变亮
        {
          if( Maikuan == 0) // 点亮
        {
            LED = ledon[j];
       }
       if(Maikuan == i) // 熄灭
        {
           LED = 0xff;
       }
      if( Maikuan== 255)   
        {
            i++;     
          }
       }
   }
   for(j=7;j>=0;j--)
   {
     i = 0;     
    while(i!=255)     // 由亮变暗
   {
     if(Maikuan == 0) // 熄灭
     {
             LED = 0xff;
      }
      if( Maikuan == i) // 点亮
       {
         LED = ledon[j];
       }
    if( Maikuan == 255)
      {
            i++;
     }
   }  
}
  
   //所有的灯逐渐从暗到全亮，再由全亮到暗。
 
   for (m=254; m>0; m--)
      {            
          while (Maikuan!=Occupy_led)
          {
                  LED = 0x00;
          }
 
          while (Maikuan!=127)
          {
                  LED = 0xff;
          }
      
         Maikuan = 0;
 
          if (light)      
          {
                 Occupy_led++;       
          }
          else
          {
                 Occupy_led--;
          }
 
          if (Occupy_led==128)
          {
                 Occupy_led = 127;
                  light = !light;    
          }
          if (Occupy_led>128)
          {
                  Occupy_led = 0;
                  light = !light;
          }
      }             
}
}