#include<reg51.h>
#include<stdio.h> //PWM调制
#include<math.h>
sbit P32=P3^2; //端口设置
sbit P33=P3^3;
sbit P10=P1^0;
unsigned int j;
void delay(unsigned int m) //延时m*1ms子程序
{
unsigned int r;
for(;m>0;m--)
{
for(r=0;r<124;r++)
{;}
}
}
void OutputPWM(void)
{
P10=!P10;
delay(500-j);
P10=!P10;
delay(j);
}
//****************************//
//主程序//
void main(void)
{
j=250;
while(1)
{
if (P32==0) //可调并且按键去抖
{delay(10);//延时10s
if(P32==0)
{j=j+50;} //步长是50s
if(P33==0)
{ delay(10); //延时10s
if (P33==0)
{j=j-50;}
}
if (j<0)j=500;
if (j>500)j=0;
}
OutputPWM();
}
}