key.c

智能小车的往返行驶,单片机实现,使用红外信号进行路面信号的采集

/*********************************************************************************************************
功能：8位并口键盘控制程序，用于IOA低8位
外部函数：void KeyScan()，用于扫描有没有键按下；KeyFlag用于判断键按下，uint ReturnKeyValue()用于返回键值，返回
的是优先编码过的8位二进制值，IOA0-7按下时返回值分别为0x0001,0x0002,0x0003,0x0004,0x0008,0x0010,0x0020,0x0040,
0x0080，当IOA0-7同时按下时，总是从IOA0开始优先编码。
*/
#include "SPCE061V004.h"
#define  DELAYTIMES   3
#define  UPDELAYTIMES 10
typedef unsigned int uint;
typedef unsigned char uchar;
void EnterKey();
void ReturnKeyValue();
uint KeyUpFlag=0,KeyDownFlag=0;
uint ioabuf=0;
uint c_key_delay=0,keyup_delay=0;
uint key_buffer=0;
uint key_array[8];
uint keyflag_buffer=0;
uint KeyUpFlagArray[8]={0,0,0,0,0,0,0,0};
uint LastKeyArray[3]={0,0,0};
uint KeyReturntimes=0;
void UpKey();
void KeyScan()
{
 *P_IOA_Data =0x00c3;
 ioabuf=*P_IOA_Data;
 ioabuf ^=0x00c3;
 if(ioabuf==0) {c_key_delay=0; UpKey();} 
 else {keyup_delay=0;EnterKey();}
}
void EnterKey()
{
      if(c_key_delay==0)
         { key_buffer=ioabuf;c_key_delay++;}
      else if(c_key_delay < DELAYTIMES )
        {
          if(key_buffer==ioabuf) c_key_delay++;
          else {c_key_delay=0;}
        }
      else 
        { KeyDownFlag=1;KeyUpFlag=0;c_key_delay=0;}
}
void UpKey()
{
      if(keyup_delay==0)
			keyup_delay++;
	  else if(keyup_delay<UPDELAYTIMES)
	     {
	      keyup_delay++;       
	     }
      else
         {
         KeyUpFlag=1;
         keyup_delay=0;
         }
}
void ReturnKeyValue()
{
  uint i=0,j=0,temp=0;
   __asm("IRQ OFF"); 
  for(i=0x0001; i<=0x0080; i=i<<1)
    {
      if(i & key_buffer)
          {
           key_array[j]=1;
          }
      j++;
    }
  if(KeyReturntimes==0)
    {
    LastKeyArray[1]=key_buffer;
    KeyReturntimes++;
    }
  else if(KeyReturntimes==1)
    {
     LastKeyArray[0]=key_buffer;
     KeyReturntimes++;
    }
  else
    {
      LastKeyArray[2]= LastKeyArray[1];
      LastKeyArray[1]= LastKeyArray[0];
      LastKeyArray[0]=key_buffer;
      keyflag_buffer=LastKeyArray[2] ^ key_buffer;
    }
   __asm("IRQ ON");
  *P_Watchdog_Clear=1;  
    j=0;
  for(i=0x0001; i<=0x0080; i=i<<1)
    {
      if(i & keyflag_buffer)
          {
           KeyUpFlagArray[j]=1;
          }
      j++;
    }
  keyflag_buffer=0;
  key_buffer=0;
 
 
}