【单片机期中测试】7.按键调光

#include<reg52.h>
sbit led=P2^0;
sbit key=P3^1;
unsigned int t=1,q=0;
void delay(unsigned int c)
{
   while(--c);
}
void delay2(unsigned int c1)
{
   for(;c1>0;c1--)
   {
    led=0;
    delay(t);
    led=1;
    delay(500-t);
   }
}
void main()
{
  unsigned int dir=0;
  while(1)
  {  
    delay2(1);
    if(key==0&&q==0)
    {
      q=1;
      if(dir==0)
      t+=100;
      else
      t-=100;
      if(t>=400) dir=1;
      if(t<=100) dir=0;
      delay2(10);
    }
    if(key==1&&q==1)
    {
      q=0;
      delay2(10);
    }
  } 
}