keyscan.c

来自「基于51单片机实现UART通信 SPI通信 和IIC通信」· C语言 代码 · 共 43 行

#include "Includes.h"

 
extern unsigned char  keyscan(void){                                                                     //键盘扫描程序  
       unsigned char  co[8]={0,0,0,0,0,0,0,0}; 
	   unsigned char m[]={"press keys"},a=0x80,i,sum;
	   unsigned char v=0; 
       sum=0;                                           
  P0=0xFF;
    P0_0=0;
    if(P0_4==0){
    v='A'; co[0]=1;}
    if(P0_5==0){
    v='B'; co[1]=1;}
    if(P0_6==0){
    v='C'; co[2]=1;}
    if(P0_7==0){
    v='D'; co[3]=1;}	
  P0=0xFF;
    P0_1=0;
    if(P0_4==0){
    v='E'; co[4]=1;}
    if(P0_5==0){
    v='F'; co[5]=1;}
    if(P0_6==0){
    v='G'; co[6]=1;}
    if(P0_7==0){
    v='H'; co[7]=1;}		
 for(i=0;i<8;i++){
                   sum+=co[i]; 
                   co[i]=0;  
			      }
   if(sum>1){
              v=0;
              WriteCommandLCM(0x01,1);
              for(i=0;i<10;i++,a++){
                                    display_lcm(m[i],a);
                                   }
              while(sum>1) keyscan();
              WriteCommandLCM(0x01,1);
              }
 return(v);
}