key.c

来自「Atmega128 学习板的详细制作资料」· C语言 代码 · 共 104 行

//#include"key4.h"
//#include<iom16v.h>
//#include<macros.h>
#define byte unsigned char
void delay1(void);
byte judge(void)
 {
    byte tmp=0;
    tmp=PINF;
	if((tmp&0x0f)!=0x0f)
	    {
		    delay1();
		   tmp=PINF;
	      if((tmp&0x0f)!=0x0f)
		    return 1;
		  else
		    return 0;
		}
 return 0;
 }

byte getkey(void)
{
    byte in=0;

    PORTE=0xef;
   if(judge())
      {
	    
	     in=PINF;
         switch (in)
         {
          case 0xee: return 0;break;
          case 0xed:return 4;break;
          case 0xeb: return 8;break;
          case 0xe7:return 12;break;
          default: break;
         }
	    
      }

    PORTE=0xdf;
   
    if(judge())
     {
	 in=PINF;
    switch (in)
    {
      case 0xde: return 1;break;
      case 0xdd: return 5;break;
      case 0xdb: return 9;break;
      case 0xd7: return 13;break;
      default: break;
    }
	
   }



    PORTE=0xbf;
    
    if(judge())
      {
	 
	 
	  in=PINF;
    switch (in)
    {
      case 0xbe: return 2;break;
      case 0xbd: return 6;break;
      case 0xbb: return 10;break;
      case 0xb7: return 14;break;
      default: break;
    }
	
      }

    PORTE=0x7f;
   
    if(judge())
      {
	  
	  in=PINF;
    switch (in)
    {
      case 0x7e: return 3;break;
      case 0x7d: return 7;break;
      case 0x7b: return 11;break;
      case 0x77: return 15;break;
      default: break;
    }

      }

return 16;
}

 void delay1(void)
{
  unsigned int i;
  for(i=0;i<2000;i++)
        // for(j=0;j<255;j++)
           ;
}