基于MCS51——多功能按键识别

#include
#define uchar unsigned char 
uchar num;


    sbit beep=P2^3;
    sbit led=P1^0;
    sbit k1=P3^4;


void delay(uchar i)
{
    uchar j,k;
    for(j=i;j>0;j--)
    for(k=125;k>0;k--);
}




void main()
{

while(1)
{
        if(k1==0)
    {
        delay(20); //延时
        if(k1==20)
        {
            while(!k1); //等待按键释放
            num++;
        }
            switch(num)
            {
                    case 1: led=0; beep=1; break;
                    case 2: beep=0; led=1; num=0; break;
            }
     }
}