1、一般都不在键盘程序中延时,而是通过隔一段时间调用(

1、一般都不在键盘程序中延时，而是通过隔一段时间调用（比如10毫秒）来扫描按键，以尽量释放CPU 资源；2、所有键盘程序基本上都是一个模式，可以处理加速键、一键多功能等情况；3、对外接口只有2个，换用不同硬件的键盘只需把该键盘程序加入工程编译即可，其他不需要作任何改动，非常方便。

基本上都是一个模式：有键?－－YES——和上次相同?－－No－－Keyold=0;退出| || YES－－Keyold ;| || Keyold==首键延时KEYDELAY?－－No－－退出| || YES－－Keyok=1; //按下不放一定时间发首键，后面发加速键| 保存键值到Keydata；(必要时译码）| Keyold=KEYDELAY-KEYLOOP(按住不放的延时);－－退出|No－－Keyold==0?－－YES－－退出|N0－－Keyok=1; //不为0说明按了键再放开，当然作按键有效处理保存键值到Keydata；(必要时译码）Keyold=0;－－退出所有键盘程序对外接口:unsigned char KeyGetCode(void) //返回按键码{key_ok=0;return(key_data);}bit KeyTest(void) //检查有无按键{KeyScan(); //键扫描return(key_ok);}//--------------------------------------------------------------------------//// 源程序大公开//// (c) Copyright 2001－2005 xuwenjun //// All Rights Reserved //// V1.00 ////--------------------------------------------------------------------------////标题: P1口行列式键盘程序////文件名: xwj_hlkey.c ////版本: V1.00 ////修改人: 徐文军E-mail:xuwenjun@ ////日期: 05-05-13 ////描述: P1口行列式键盘程序////声明: //// 以下代码仅免费提供给学习用途，但引用或修改后必须在文件中声明出处. //// 如用于商业用途请与作者联系. E-mail:xuwenjun@ //// 有问题请mailto xuwenjun@欢迎与我交流! ////--------------------------------------------------------------------------////老版本: 无老版本文件名: ////创建人: 徐文军E-mail:xuwenjun@ ////日期: 05-05-13 ////--------------------------------------------------------------------------//#include <reg52.h>#include "xwj_hlkey.h" // P1口行列式键盘////#include "xwj_bp.h" //峰鸣器#define KEYDELAY 25 /*首键延迟次数*/#define KEYLOOP 10 /*连续键间隔次数,需小于KEYDELAY*/unsigned char key_bak;unsigned char key_temp;unsigned char key_old;unsigned char key_data;bit key_ok;// P1口行列式键盘//#define KEYPIN_L P1 // 定义键扫描列端口为P1低四位输入//#define KEYPIN_H P1 // 定义键扫描行端口为P1高四位扫描输出////内部私有函数//unsigned char fnKeycode(unsigned char key); // 根据键盘映射表输出顺序键值// // P1口行列式键盘////---------------------------------------------------------------------------//void KeyScan(void) //键扫描{unsigned char sccode,recode;KEYPIN_L = KEYPIN_L|0x0f; // P1低四位为列线输入//KEYPIN_H = KEYPIN_H&0x0f; // P1高四位为行线发全零扫描码//if ((KEYPIN_L&0x0f) != 0x0f) //有键按下{key_temp = 键值; //键扫描，获得键值if (key_temp == key_bak){key_old ;if (key_old==KEYDELAY) //连续键,不要则把此if屏蔽{key_ok=1;key_data=fnKeycode(key_temp); //键解码key_old=KEYDELAY-KEYLOOP;}}else{key_old=0;key_bak=key_temp;}}else //键抬起{if (key_old){key_ok=1;key_data=fnKeycode(key_temp); //键解码/* if (key_old==100) //加上时间,不同时间不同功能,与连续键冲突{bp(1);key_data = 0x10;}if (key_old==200){bp(2);key_data = 0x20;}*/}key_old=0;}KEYPIN_H = KEYPIN_H|0xf0;}//---------------------------------------------------------------------------// unsigned char KeyGetcode(void) //返回按键码{key_ok=0;return(key_data);}bit KeyTest(void) //检查有无按键{KeyScan(); //键扫描return(key_ok);}键盘接口软件设计键盘接口软件设计软件设计要考虑以下3部分内容：键盘缓冲区的设置；初始化程序；中断服务程序。

1、键盘缓冲区键盘缓冲区地址为：30H-4FH，共32个字节。

使用R1作为缓冲区放数指针，R7为取数指针。

缓冲区为环形。

放满后将R1置为30H，再从头放数；当放数指针追上取数指针时，停止放数。

当取数指针追上放数指针时，停止取数。

2、初始化程序包括8052的初始化和键盘的初始化。

程序清单如下：MOV IE,#0H ；关中断CLR F0 ；F0=0为类型1键盘；F0=1为类型2键盘MOV R0,#0HMOV R1,#30H ；置缓冲区放数指针起始值MOV R2,#0HMOV R3,#0HMOV R4,#0HMOV R5,#0HMOV R6,#0HMOV R7,#2FH ；置缓冲区取数指针起始值MOV B,#0HMOV TCON,#0H ；置INT0为电平触发方式KEYINT: ；主中断服务程序MOV IE,#0H ；关中断MOV A,R7 ；取数指针放到AXRL A,R1 ；与放数指针比较JZ KL4 ；放数指针=取数指针则退出INC R0 ；脉冲计数KL1: JNB P3.2,KL1 ；等待时钟脉冲为“1”CJNE R0,#01H,K12 ；首次收到脉冲则判断键盘类型MOV C,P1.0KL2:JB F0,KL3 ；根据F0的值转不同服务程序MOV F0,C ；保存键盘类型MOV C,P1.0 ；采用数据LCALL INTB ；类型2键盘中断服务程序MOV IE,#81H ；开中断RETIKL3: MOV C,P1.0 ；采样数据LCALL INTA ；类型1键盘中断服务程序KL4: MOV IE,#81H ；开中断RETI限于篇幅，以下公列出类型1键盘中断服务子程序的处理程序，类型2键盘中断服务子程序除需要进行奇校验及计数脉冲个数不同外，流程基本一致。

类型1键盘中断服务子程序：INTA:MOV A,R2 ；数据位移入R2和R3中RRC AMOV R2,AMOV A,R3RRC AMOV R3,ACJNE R0,#0AH,INTA1 ；计数脉冲不为10退出，否则转换CLR CMOV A,R3RLC AMOV A,R2RLC AMOV R5,A ；数据存入R5ANL A,#80HJNZ INTA3 ；是否为放键码，是则退出MOV A,R5MOV DPTR,#1000H ；1000H为码表转换区起址MOVC A,@A DPTR ；扫描码转换为ASCII码MOV @R1,A ；ASCII码存入键盘缓冲区INC R1CJNE R1,#50H,INTA3MOV R1,#30H ；缓冲区满则R1=30HINTA3: CJNE R7,#2FH,INT4MOV R7,#30HINTA4: MOV R0,#0H ；脉冲计数清零MOV R5,#0HINTA2: MOV R2,#0HMOV R3,#0HINTA1: RETORG 1000H ；码表转换区ORG 1002H ；这里仅列出0-9的转换表DB 31H,32H,33H,34H,35H,36H,37H,38H,39H,30H按键扫描驱动程序按键扫描驱动程序//按键扫描驱动程序unsigned char key,key_h,kpush;unsigned int key_l;//按键连接到p1.0、p1.1、p1.2void int_t0(void) interrupt 1 {unsigned char dd,i;TL0=TL0 30;TH0=0xfb; //800/* 按键判别*/if ((P1&0x7)==0x7) {if ((key_l>30)&&(key_l<800)&&(key_h>30)) { //释放按键，如果之前按键时间少于1秒，读入键值key=kpush;}if (( key_h)>200) key_h=200;key_l=0;if (key>=0x80) key=0; //如果之前的按键为长按1秒，清除键值} else {kpush=P1&0x7;key_l ;if ((key_l>800)&&(key_h>30)) { //如果按键超过1秒，键值加0x80标志长按键key=kpush|0x80;key_h=0;key_l=0;}}}void main(void) {TMOD=0x1;TR0=1;ET0=1;EA=1;while (1) {while (!key) {}switch (key) {case 1:break;case 2:break;}}}支持键盘双击事件的C程序设计！/********************************************************************************** KeyBoard Encode ProgramThis Program can encode press_key up to 128 and it can deal KB_DBClick MessageThis is just a test proram and only use 2 key.If More Key need to Encode ,pleasemodify the function:KBKeyPress()This Porgram use Message_Driver method,the KB_Msg is used to record what KB_Msg has occured. The meaning of 'SysKBMsg' is list as following.Program Design:LiBaizhanVer:1.10Date:2003-3-16************************************************************************************/ #include <reg51.h>#include <intrins.h>sbit Key1 = P1^0;sbit Key2 = P1^1;/*Some System Var Pre_DefinitionCrystal Frequence is 11.0592MHz*/#define TIME_2MS 0X74#define TIME_20MS 0X043B#define KB_INTERNAL 3 /*Key DBClk Detection Internal *//*SysKBMsg define Keyboard Message,it include Single_Click or Double_ClickIt's bit6~bit0 record key_encode and bit 7 record DBClk(1) or SglClk(0)It can record and encode up to 127(2^7-1) keysNo key is press when it is 0This method did not deal key such as Ctrl_Key or Alt_Key or Shift_Key...etc.*//*_________________________________________________*/data unsigned char SysKBMsg=0; /*| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |*//*| D/S | KB6 | KB5 | KB4 | KB3 | KB2 | KB1 | KB0 |*/data unsigned char KBCounter=0;bit KBCounterStart=0;bit KBCounterStop=0; /*if KeyBoard counter stop then this bit is 1*/bit KBCounterFlag=0; /*Current Counter is used by KeyBoard*/void TimerInt0(void) interrupt 1 /*timer 0 interrupt use to record how long key is press*/{TR0=0;if(KBCounterFlag) /*Current Counter is used by KeyBoard*/{if(KBCounter<KB_INTERNAL) /*if DBClk Detection is not finish then detect continue*/{KBCounter ;TR0=1;}else{KBCounter=0; /*DBClk Detection is finish*/KBCounterStop=1;}}}void DelayMS(unsigned int dltime);void Init51(void);unsigned char KBKeyPress(void); /*only return what key is press*/void KBKeyEncode(void); /*encode which key is pressed and DBClk or SglClk*/void KBStartTimer(unsigned char CntH,unsigned char CntL); /*load counter initial value and start timer*/ void KBStopTimer(void);void KBDealPressKey(void); /*deal key_press message*/void main(void){Init51();while(1){KBKeyEncode(); /*recored what KeyBoard Msg occure:which key is press and single clk or db clk*/ KBDealPressKey();}}/*Delay Time is :(20 17*dl_time)*12/CrystalFrequence(us)*/void DelayMS(unsigned int dltime){unsigned int i;for(i=0;i<dltime;i );}void Init51(void)SCON = 0x50; /* mode 1: 8-bit UART, enable receiver */TMOD = 0x21; /* timer 1 mode 2: 8-Bit reload *//* timer 0 mode 1: 16-bit Timer */TH1 = BAUD_4800; /* reload value 9600 baud */TR1 = 1; /* timer 1 run */IE = 0X12; /* enable Serial INT,Timer0 INT */ES = 0; /* disable Serial INT*/EA = 1; /* Open INT Ctrl */}void KBKeyEncode(void){data unsigned char CurrPress=0,LastPress=0;if((LastPress=KBKeyPress())!=0) /*if some key is press then start encode*/{KBStartTimer(0,0); /*some key is press then start DBClk Detection Counter*/SysKBMsg=LastPress; /*record the key that is pressed this time*/while(!KBCounterStop){if((CurrPress=KBKeyPress())!=0X0) /*if some key is pressed during DBClk Detection then jump out to see wether DBclk is occured*/break;}if((KBCounterStop==0)&&(LastPress==CurrPress)) /*this key DBClk occured*/SysKBMsg|=0X80;KBStopTimer();}}unsigned char KBKeyPress(void){data unsigned char KeyPress=0;if((P1&0X03)!=0X03){DelayMS(TIME_20MS);if((KeyPress=(P1&0X03))!=0X03) /*some key is press*/{if(KBCounterStart)TR0=0;while((P1&0X03)!=0X03); /*wait until key is free*/DelayMS(TIME_20MS);if(KBCounterStart)TR0=1;}else /*Key is not real press*/KeyPress=0;}}return KeyPress;}void KBStartTimer(unsigned char CntH,unsigned char CntL){TR0=0;TH0=CntH;TR0=1; /*Start Counter*/TL0=CntL;KBCounterFlag=1; /*this counter is used by KeyBoard*/KBCounterStart=1;KBCounterStop=0;}void KBStopTimer(void){TR0=0;TH0=0;TL0=0;KBCounter=0;KBCounterFlag=0;KBCounterStart=0;}void KBDealPressKey(void){data unsigned char tmp=0;switch(SysKBMsg) /*here is just a test program,test to deal Sgl_Clk and DB_Clk Msg*/ {case 0X01: tmp=0X01;break;case 0X02: tmp=0X02;break;case 0X81: tmp=0X81;break;case 0X82: tmp=0X82;break;default : break;}SysKBMsg=0; /*this key msg has been done*/from: 作者：李佰战一种软件去除键抖动的方法来源：单片机及嵌入式系统应用肖广安时间：2006-05-16 发布人:meitai 概述在单片机控制系统中，通过按键实现控制功能是很常见的。