缘由C51，四个按键控制流水灯-嵌入式-CSDN问答

#include "REG52.h"
sbit k1=P3^0;
sbit k2=P3^1;
sbit k3=P3^2;
sbit k4=P3^3;
unsigned char code lsd[]={127,191,223,239,247,251,253,254};//跑马灯
void jsys(unsigned char y,unsigned char s){unsigned char ss;ss=s;while(--y){while(--ss);ss=s;}}
void main()
{unsigned char xd=0,q=0xaa,o=0x55,x=0,l=0;P1=255;while(1){if(k1==0&&++xd==0){P1=q;while(k1==0);}if(k2==0&&++xd==0){P1=o;while(k2==0);}if(k3==0&&++xd==0){while(x<20){jsys(255,255);if(x%2)P1=q;else P1=o;++x;}x=0;}if(k4==0&&++xd==0){P1=255;while(x<10){jsys(255,255);jsys(255,255);P1=lsd[l];if(++l==9){++x;P1=255;l=0;}}x=l=0;}}
}