单片机按键状态机问题求解

只看该作者 · 2013-3-13 18:03

学习状态机遇到了问题，向论坛里的大牛求解，谢谢了！！！
#include<reg52.h>

#define uchar unsigned char
#define uint  unsigned int

#define KEY_VALUE_1             0xe0
#define KEY_VALUE_2             0xd0
#define KEY_VALUE_3             0xb0
#define KEY_VALUE_4             0x70
#define KEY_NULL                0xf0

sbit io_key_1 = P3^4 ;
sbit io_key_2 = P3^5 ;
sbit io_key_3 = P3^6 ;
sbit io_key_4 = P3^7 ;

static uint KeyScan(void)
{
if(io_key_1 == 0)return KEY_VALUE_1 ;
if(io_key_2 == 0)return KEY_VALUE_2 ;
if(io_key_3 == 0)return KEY_VALUE_3 ;
if(io_key_4 == 0)return KEY_VALUE_4 ;
return KEY_NULL ;
}
void KeyInit(void)
{
io_key_1 = 1 ;
io_key_2 = 1 ;
io_key_3 = 1 ;
io_key_4 = 1 ;
}

#define KEY_LONG_PERIOD       100
#define KEY_CONTINUE_PERIOD 25

#define KEY_DOWN             0x08
#define KEY_LONG             0x04
#define KEY_CONTINUE          0x02
#define KEY_UP                0x01

#define KEY_STATE_INIT          0
#define KEY_STATE_WOBBLE       1
#define KEY_STATE_PRESS          2
#define KEY_STATE_LONG          3
#define KEY_STATE_CONTINUE       4
#define KEY_STATE_RELEASE       5

unsigned char timer0_10ms_flag;

void GetKey(uint *pKeyValue)
{
static uint s_u8KeyState = KEY_STATE_INIT ;
static uint s_u8KeyTimeCount = 0 ;
static uint s_u8LastKey = KEY_NULL ; //保存按键释放时候的键值
uint KeyTemp = KEY_NULL;
KeyTemp = KeyScan() ;       //获取键值
switch(s_u8KeyState)
{
      case KEY_STATE_INIT :
            {
                  if(KEY_NULL != (KeyTemp))
                  {
                     s_u8KeyState = KEY_STATE_WOBBLE ;
                  }
            }
      break ;
      case KEY_STATE_WOBBLE :    //消抖
            {
                  s_u8KeyState = KEY_STATE_PRESS ;
            }
      break ;
      case KEY_STATE_PRESS :
            {
                  if(KEY_NULL != (KeyTemp))
                  {
                     s_u8LastKey = KeyTemp ; //保存键值,以便在释放按键状态返回键值
                     KeyTemp |= KEY_DOWN ; //按键按下
                     s_u8KeyState = KEY_STATE_LONG ;
                  }
                  else
                  {
                     s_u8KeyState = KEY_STATE_INIT ;
                  }
            }
      break ;
      case KEY_STATE_LONG :
            {
                  if(KEY_NULL != (KeyTemp))
                  {
                     if(++s_u8KeyTimeCount > KEY_LONG_PERIOD)
                     {
                        s_u8KeyTimeCount = 0 ;
                        KeyTemp |= KEY_LONG ; //长按键事件发生
                        s_u8KeyState = KEY_STATE_CONTINUE ;
                     }
                  }
                  else
                  {
                     s_u8KeyState = KEY_STATE_RELEASE ;
                  }
            }
      break ;
      case KEY_STATE_CONTINUE :
            {
                  if(KEY_NULL != (KeyTemp))
                  {
                     if(++s_u8KeyTimeCount > KEY_CONTINUE_PERIOD)
                     {
                        s_u8KeyTimeCount = 0 ;
                        KeyTemp |= KEY_CONTINUE ;
                     }
                  }
                  else
                  {
                     s_u8KeyState = KEY_STATE_RELEASE ;
                  }
            }
      break ;
      case KEY_STATE_RELEASE :
            {
                  s_u8LastKey |= KEY_UP ;
                  KeyTemp = s_u8LastKey ;
                  s_u8KeyState = KEY_STATE_INIT ;
            }
      break ;
      default : break ;
}
*pKeyValue= KeyTemp ; //返回键值
}

void init()
{
TH0=(65536-10000)/256;
TL0=(65536-10000)%256;
EA=1;
ET0=1;
TR0=1;
}

void timer0() interrupt 1
{
TH0=(65536-10000)/256;
TL0=(65536-10000)%256;
timer0_10ms_flag=1;
}
void mian()
{
uint KeyValue=KEY_NULL;
init();
KeyInit();
while(1)
{
      Timer0MainLoop();
         KeyMainLoop(&KeyValue);

if(KeyValue == (KEY_VALUE_1 | KEY_DOWN)) P1 = ~1 ;

      if(KeyValue == (KEY_VALUE_1 | KEY_LONG)) P1 = ~2 ;

      if(KeyValue == (KEY_VALUE_1 | KEY_CONTINUE)) { P1 ^= 0xf0;}

      if(KeyValue == (KEY_VALUE_1 | KEY_UP)) P1 = 0xa5 ;

}
}
下面的两个函数怎么来的
Timer0MainLoop();
KeyMainLoop(&KeyValue);
具体的内容是什么？？
向大牛求解。