基于51单片机的脉冲信号计数并报警源代码

#include<reg52.h>

sbit key=P2^0;
sbit led=P0^0;

void main()
{
unsigned int i = 0;
while(1)
{
key = 1;
if(key==0)
{
while(!key);
i++;

}

if(i >= 334 && i <=668)
{
led = 0;
if(i == 668)
i = 0;
}
else
{
led = 1;

}
}