51单片机实现led灯亮度变化！

#include <STC15F2K60S2.H>
unsigned int count=0;
unsigned int num=10;
#define  k1   P33
#define  k2   P32
void Delay5ms()        //@11.0592MHz
{
    unsigned char i, j;
    i = 54;
    j = 199;
    do
    {
        while (--j);
    } while (--i);
}
void Timer0Init(void)        /16 1T
{
    AUXR |= 0x80;        //?????1T??
    TMOD &= 0xF0;        //???????
    TMOD |= 0x01;        //???????
    TL0 = 0xD7;        //??????
    TH0 = 0xFD;        //??????
    TF0 = 0;        //??TF0??
    TR0 = 1;    
  EA=1;
  ET0=1;    //???0????
}
void main()
{
 Timer0Init();
    
    P2=P2&0x1f|0x80;
        P0=0xff;
    while(1)
    { 
        if(k1==0){
            Delay5ms(); if(k1==0)    
          num=10;
        
    } 
    
      if(k2==0){
            Delay5ms(); if(k2==0)
          num=20;    
      }
        
        
        if(P31==0){
                Delay5ms(); if(P31==0)
                num=30;
            }
            
         if(P30==0){
                Delay5ms();
                if(P30==0)
           num=40;
  
         }
    
    }
void timer0() interrupt 1
{
      TL0 = 0xD7;        //??????
      TH0 = 0xFD;        //50us
    count++;
    
    if(count>num)count=0;
    
    if(count>=10)
    {
   P2=P2&0x1f|0x80;
      P02=1;
       
    }
else
     {
         P2=P2&0x1f|0x80;
           P02=0;
    
       }
 
}