这是一个可以识别四个独立按键是短按还是长按的参考程序，此程序已编译通过，初学者可以移植到51单片机上试试．
/********************************************/
//FileName:识别四个独立按键是短按还是长按
//Function: 不同按键 短按或长按分别显示不同的LED
//author:liu yong
//QQ:545018331
//Date:2013/03/13
/********************************************/
#include <PIC.H>
__CONFIG(0X3B31);
#define uint8 unsigned char
unsigned int time_10ms_ok=0;
uint8 KeyValue;
bit KeyShortpressFlag,KeyLongpressFlag;
//＝＝＝＝＝＝＝＝＝定义长按键断口的TICK数及连发间隔的TICK数＝＝＝＝＝＝＝//
#define KEY_LONG_PERIOD 200
//＝＝＝＝＝＝＝＝＝定义按键断口＝＝＝＝＝＝＝//
#define io_key_1 RB0
#define io_key_2 RB1
#define io_key_3 RB2
#define io_key_4 RB3
//＝＝＝＝＝＝＝＝＝定义按键键值＝＝＝＝＝＝＝//
#define KEY_VALUE_1 0X0e
#define KEY_VALUE_2 0X0d
#define KEY_VALUE_3 0X0b
#define KEY_VALUE_4 0X07
#define KEY_NULL 0X0f
//＝＝＝＝＝＝＝＝＝定义按键返回值状态（按下，长按，连发，释放）＝＝＝＝＝＝＝//
#define KEY_SHORT 0X80
#define KEY_LONG 0X40
//＝＝＝＝＝＝＝＝＝定义按键状态＝＝＝＝＝＝＝//
#define KEY_STATE_INIT 0
#define KEY_STATE_WOBBLE 1
#define KEY_STATE_PRESS 2
#define KEY_STATE_LONG 3
#define KEY_STATE_RELEASE 4
void initial(void)
{
TRISB=0xff;
TRISC=0;
PORTC=0XFF;
RBPU=0;
T1CON=0X01;//1:1
TMR1H=-(10000 >> 8);
TMR1L=-(10000 & 0XFF);
TMR1IF=0;
TMR1IE=1;
INTCON=0XC0;
}
void interrupt timer1_isr(void) // 定时器10ms中断服务
{
if(TMR1IF)
{
TMR1H=-(10000 >> 8);
TMR1L=-(10000 & 0XFF);
time_10ms_ok = 1;
TMR1IF=0;
}
}
void KeyInit(void)
{
io_key_1 = 1;
io_key_2 = 1;
io_key_3 = 1;
io_key_4 = 1;
}
uint8 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;
}
uint8 GetKey(void)
{
static uint8 s_u8KeyState = KEY_STATE_INIT ;
static uint8 s_u8KeyTimeCount = 0;
uint8 i ;
uint8 KeyTemp=KEY_NULL;
KeyTemp = KeyScan();//0x0e 0f
switch(s_u8KeyState)
{
case KEY_STATE_INIT:
{
if(KEY_NULL != KeyTemp)
{
s_u8KeyState = KEY_STATE_WOBBLE ;
}
}
break;
case KEY_STATE_WOBBLE:
{
s_u8KeyState = KEY_STATE_PRESS ;
}
break;
case KEY_STATE_PRESS://识别哪个键
{
if(KEY_NULL != KeyTemp) // KeyTemp=0x0e short press
{
s_u8KeyState = KEY_STATE_LONG ;
i=KeyTemp;//0x0e
}
else
{
s_u8KeyState = KEY_STATE_INIT;
}
}
break;
case KEY_STATE_LONG: //判断按键是短按还是长按
{
if(KEY_NULL != KeyTemp)
{
if(++s_u8KeyTimeCount > KEY_LONG_PERIOD)
{
s_u8KeyTimeCount = 0;
KeyLongpressFlag=1;
KeyShortpressFlag=0;
s_u8KeyState = KEY_STATE_RELEASE;
}
}
else
{
s_u8KeyTimeCount = 0;
KeyShortpressFlag=1;
KeyLongpressFlag=0;
s_u8KeyState = KEY_STATE_RELEASE;
}
}
break;
case KEY_STATE_RELEASE://按键释放去抖
{
if(KEY_NULL == KeyTemp) //此语句必须加上去不然程序不稳定
{
if(KeyShortpressFlag)
{
KeyShortpressFlag=0;
i=i | KEY_SHORT;//0x0e | 0x80=0x8e
s_u8KeyState = KEY_STATE_INIT;
}
if(KeyLongpressFlag)
{
KeyLongpressFlag=0;
i=i | KEY_LONG;
s_u8KeyState = KEY_STATE_INIT;
}
}
}
break;
default:break;
}
return i;
}
void main(void)
{
initial();
KeyInit();
while(1)
{
if (time_10ms_ok) //每10ms执行一次，
{
time_10ms_ok =0;
KeyValue=GetKey();
if(KeyValue == (KEY_VALUE_1 | KEY_SHORT)) PORTC = ~1;
if(KeyValue == (KEY_VALUE_1 | KEY_LONG)) PORTC = ~3;
if(KeyValue == (KEY_VALUE_2 | KEY_SHORT))PORTC = ~7;
if(KeyValue == (KEY_VALUE_2 | KEY_LONG)) PORTC = ~0X0F;
if(KeyValue == (KEY_VALUE_3 | KEY_SHORT))PORTC = ~0X1F;
if(KeyValue == (KEY_VALUE_3 | KEY_LONG)) PORTC = ~0X3F;
if(KeyValue == (KEY_VALUE_4 | KEY_SHORT)) PORTC = ~0X7F;
if(KeyValue == (KEY_VALUE_4 | KEY_LONG)) PORTC = ~0XFF;
}
}
}