单片机：K1 K2 K3 K4应用：K1循环左移 K2停止 K3 左移 K4 二进制减法 流水灯控制

#include <reg52.h>
#include<intrins.h>
sbit key1=P3^2;
sbit key2=P3^3;
sbit key3=P3^4;
sbit key4=P3^5;
typedef  unsigned int uint;
typedef  unsigned char uchar;
void delay(uint a)
{
uchar i;
while(a--)for(i=0;i<110;i++);
}
main()
{ 
    uchar led=0x7f;
    uchar flag=0;
    while (1)
    {
        if(key1==0)
        {
        delay(5);
        if(key1==0)
            {
            while(key1==0);
            flag=1;
            //led=0xfe;
            }
        }
    if(key2==0)
        {
        delay(5);
        if(key2==0)
            {
            while(key2==0);
            flag=2;
            }
        }
        if(key3==0)
        {
        delay(5);
        if(key3==0)
            {
            while(key3==0);
            flag=3;
            }
        }
                if(key4==0)
        {
        delay(5);
        if(key4==0)
            {
            while(key4==0);
            flag=4;
            }
        }
    switch(flag)
        {
        case 1:P1=led;led=_crol_(led,1);delay(1700);break;
        case 2:P1=0xff;break;
        case 3:P1=P1<<1;delay(1700); if (P1==0X00)  P1=0XFF; break;
              //case 4:P1=~P1;delay(1000);break;
            case 4:P1--;delay(200);break;
        default:continue;
        }
    }
    
            
    }