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|   选择分类:当前分类——当前分类    相关联或者相类似的文章:    14.            4×4矩阵式键盘识别技术(512) 走向单片机世界(512) BA1404调频立体声发射芯片的原理与应用(511) BA1404/1404F 调频立体声发射电路(511) 用PROTEL DXP电路板设计的一般原则(510) 利用TL431作大功率可调稳压电源(509) 电子元器件基本常识:常见的液晶显示器(509) 10. 00-99计数器(509) 电热毯自动保护恒温器(509) 也能称为“公益事业”(508) BH1417的高保真锁相环调频立体声发射模块(508) 怎样用多个开关控制一盏灯(507) 实用电工速算口诀集(507) 浅谈干簧管的应用(506) 密封铅酸蓄电池充电器设计实例(506) 测电流法(505) 器件的筛选与检测(505) 几款直流升压电路(504) 28. 数字电压表(503) 防抖动轻触开关(503) 首页 前页 后页 尾页  本站推荐:        |    14.            4×4矩阵式键盘识别技术 1. 实验任务  
如图4.14.2所示,用AT89S51的并行口P1接4×4矩阵键盘,以P1.0-P1.3作输入线,以P1.4-P1.7作输出线;在数码管上显示每个按键的“0-F”序号。对应的按键的序号排列如图4.14.1所示 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
     
图4.14.1  
2. 硬件电路原理图  
    图4.14.2  
3. 系统板上硬件连线  
(1.       把“单片机系统“区域中的P3.0-P3.7端口用8芯排线连接到“4X4行列式键盘”区域中的C1-C4 R1-R4端口上; 
(2.       把“单片机系统”区域中的P0.0/AD0-P0.7/AD7端口用8芯排线连接到“四路静态数码显示模块”区域中的任一个a-h端口上;要求:P0.0/AD0对应着a,P0.1/AD1对应着b,……,P0.7/AD7对应着h。  
4.  程序设计内容  
(1.       4×4矩阵键盘识别处理  
(2.       每个按键有它的行值和列值 ,行值和列值的组合就是识别这个按键的编码。矩阵的行线和列线分别通过两并行接口和CPU通信。每个按键的状态同样需变成数字量“0”和“1”,开关的一端(列线)通过电阻接VCC,而接地是通过程序输出数字“0”实现的。键盘处理程序的任务是:确定有无键按下,判断哪一个键按下,键的功能是什么;还要消除按键在闭合或断开时的抖动。两个并行口中,一个输出扫描码,使按键逐行动态接地,另一个并行口输入按键状态,由行扫描值和回馈信号共同形成键编码而识别按键,通过软件查表,查出该键的功能。  
5. 程序框图  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
     
图4.14.3  
6. 汇编源程序  
KEYBUF    EQU 30H  
            ORG 00H  
START:      MOV KEYBUF,#2  
WAIT:    
            MOV P3,#0FFH  
            CLR P3.4  
            MOV A,P3  
            ANL A,#0FH   
            XRL A,#0FH  
            JZ NOKEY1  
            LCALL DELY10MS  
            MOV A,P3  
            ANL A,#0FH  
            XRL A,#0FH  
            JZ NOKEY1  
            MOV A,P3  
            ANL A,#0FH  
            CJNE A,#0EH,NK1  
            MOV KEYBUF,#0  
            LJMP DK1  
NK1:        CJNE A,#0DH,NK2  
            MOV KEYBUF,#1  
            LJMP DK1  
NK2:        CJNE A,#0BH,NK3  
            MOV KEYBUF,#2  
            LJMP DK1  
NK3:        CJNE A,#07H,NK4  
            MOV KEYBUF,#3  
            LJMP DK1  
NK4:        NOP  
DK1:     
            MOV A,KEYBUF  
            MOV DPTR,#TABLE  
            MOVC A,@A+DPTR  
            MOV P0,A  
DK1A:       MOV A,P3  
            ANL A,#0FH  
            XRL A,#0FH  
            JNZ DK1A  
NOKEY1:  
            MOV P3,#0FFH  
            CLR P3.5  
            MOV A,P3  
            ANL A,#0FH  
            XRL A,#0FH  
            JZ NOKEY2  
            LCALL DELY10MS  
            MOV A,P3  
            ANL A,#0FH  
            XRL A,#0FH  
            JZ NOKEY2  
            MOV A,P3  
            ANL A,#0FH  
            CJNE A,#0EH,NK5  
            MOV KEYBUF,#4  
            LJMP DK2  
NK5:        CJNE A,#0DH,NK6  
            MOV KEYBUF,#5  
            LJMP DK2  
NK6:        CJNE A,#0BH,NK7  
            MOV KEYBUF,#6  
            LJMP DK2  
NK7:        CJNE A,#07H,NK8  
            MOV KEYBUF,#7  
            LJMP DK2  
NK8:        NOP  
DK2:     
            MOV A,KEYBUF  
            MOV DPTR,#TABLE  
            MOVC A,@A+DPTR  
            MOV P0,A  
DK2A:       MOV A,P3  
            ANL A,#0FH  
            XRL A,#0FH  
            JNZ DK2A  
NOKEY2:  
            MOV P3,#0FFH  
            CLR P3.6  
            MOV A,P3  
            ANL A,#0FH  
            XRL A,#0FH  
            JZ NOKEY3  
            LCALL DELY10MS  
            MOV A,P3  
            ANL A,#0FH  
            XRL A,#0FH  
            JZ NOKEY3  
            MOV A,P3  
            ANL A,#0FH  
            CJNE A,#0EH,NK9  
            MOV KEYBUF,#8  
            LJMP DK3  
NK9:        CJNE A,#0DH,NK10  
            MOV KEYBUF,#9  
            LJMP DK3  
NK10:       CJNE A,#0BH,NK11  
            MOV KEYBUF,#10  
            LJMP DK3  
NK11:       CJNE A,#07H,NK12  
            MOV KEYBUF,#11  
            LJMP DK3  
NK12:       NOP  
DK3:  
            MOV A,KEYBUF  
            MOV DPTR,#TABLE  
            MOVC A,@A+DPTR  
            MOV P0,A  
DK3A:       MOV A,P3  
            ANL A,#0FH  
            XRL A,#0FH  
            JNZ DK3A  
NOKEY3:  
            MOV P3,#0FFH  
            CLR P3.7  
            MOV A,P3  
            ANL A,#0FH  
            XRL A,#0FH  
            JZ NOKEY4  
            LCALL DELY10MS  
            MOV A,P3  
            ANL A,#0FH  
            XRL A,#0FH  
            JZ NOKEY4  
            MOV A,P3  
            ANL A,#0FH  
            CJNE A,#0EH,NK13  
            MOV KEYBUF,#12  
            LJMP DK4  
NK13:       CJNE A,#0DH,NK14  
            MOV KEYBUF,#13  
            LJMP DK4  
NK14:       CJNE A,#0BH,NK15  
            MOV KEYBUF,#14  
            LJMP DK4  
NK15:       CJNE A,#07H,NK16  
            MOV KEYBUF,#15  
            LJMP DK4  
NK16:       NOP  
DK4:     
            MOV A,KEYBUF  
            MOV DPTR,#TABLE  
            MOVC A,@A+DPTR  
            MOV P0,A  
DK4A:       MOV A,P3  
            ANL A,#0FH  
            XRL A,#0FH  
            JNZ DK4A  
NOKEY4:  
            LJMP WAIT  
DELY10MS:  
            MOV R6,#10  
D1:         MOV R7,#248  
            DJNZ R7,$  
            DJNZ R6,D1  
            RET  
TABLE:      DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H  
            DB 7FH,6FH,77H,7CH,39H,5EH,79H,71H  
            END  
7. C语言源程序  
#include <AT89X51.H>  
unsigned char code table[]={0x3f,0x06,0x5b,0x4f,  
                            0x66,0x6d,0x7d,0x07,  
                            0x7f,0x6f,0x77,0x7c,  
                            0x39,0x5e,0x79,0x71};  
unsigned char temp;  
unsigned char key;  
unsigned char i,j;  
void main(void)  
{  
  while(1)  
    {  
      P3=0xff;  
      P3_4=0;  
      temp=P3;  
      temp=temp & 0x0f;  
      if (temp!=0x0f)  
        {  
          for(i=50;i>0;i--)  
          for(j=200;j>0;j--);  
          temp=P3;  
          temp=temp & 0x0f;  
          if (temp!=0x0f)  
            {  
              temp=P3;  
              temp=temp & 0x0f;               
              switch(temp)  
                {  
                  case 0x0e:  
                    key=7;  
                    break;  
                  case 0x0d:  
                    key=8;  
                    break;  
                  case 0x0b:  
                    key=9;  
                    break;  
                  case 0x07:  
                    key=10;  
                    break;  
                }  
              temp=P3;  
              P1_0=~P1_0;  
              P0=table[key];  
              temp=temp & 0x0f;               
              while(temp!=0x0f)  
                {  
                  temp=P3;  
                  temp=temp & 0x0f;               
                }  
            }  
        }  
      P3=0xff;  
      P3_5=0;  
      temp=P3;  
      temp=temp & 0x0f;  
      if (temp!=0x0f)  
        {  
          for(i=50;i>0;i--)  
          for(j=200;j>0;j--);  
          temp=P3;  
          temp=temp & 0x0f;  
          if (temp!=0x0f)  
            {  
              temp=P3;  
              temp=temp & 0x0f;               
              switch(temp)  
                {  
                  case 0x0e:  
                    key=4;  
                    break;  
                  case 0x0d:  
                    key=5;  
                    break;  
                  case 0x0b:  
                    key=6;  
                    break;  
                  case 0x07:  
                    key=11;  
                    break;  
                }  
              temp=P3;  
              P1_0=~P1_0;  
              P0=table[key];  
              temp=temp & 0x0f;               
              while(temp!=0x0f)  
                {  
                  temp=P3;  
                  temp=temp & 0x0f;               
                }  
            }  
        }  
      P3=0xff;  
      P3_6=0;  
      temp=P3;  
      temp=temp & 0x0f;  
      if (temp!=0x0f)  
        {  
          for(i=50;i>0;i--)  
          for(j=200;j>0;j--);  
          temp=P3;  
          temp=temp & 0x0f;  
          if (temp!=0x0f)  
            {  
              temp=P3;  
              temp=temp & 0x0f;               
              switch(temp)  
                {  
                  case 0x0e:  
                    key=1;  
                    break;  
                  case 0x0d:  
                    key=2;  
                    break;  
                  case 0x0b:  
                    key=3;  
                    break;  
                  case 0x07:  
                    key=12;  
                    break;  
                }  
              temp=P3;  
              P1_0=~P1_0;  
              P0=table[key];  
              temp=temp & 0x0f;               
              while(temp!=0x0f)  
                {  
                  temp=P3;  
                  temp=temp & 0x0f;               
                }  
            }  
        }  
      P3=0xff;  
      P3_7=0;  
      temp=P3;  
      temp=temp & 0x0f;  
      if (temp!=0x0f)  
        {  
          for(i=50;i>0;i--)  
          for(j=200;j>0;j--);  
          temp=P3;  
          temp=temp & 0x0f;  
          if (temp!=0x0f)  
            {  
              temp=P3;  
              temp=temp & 0x0f;               
              switch(temp)  
                {  
                  case 0x0e:  
                    key=0;  
                    break;  
                  case 0x0d:  
                    key=13;  
                    break;  
                  case 0x0b:  
                    key=14;  
                    break;  
                  case 0x07:  
                    key=15;  
                    break;  
                }  
              temp=P3;  
              P1_0=~P1_0;  
              P0=table[key];  
              temp=temp & 0x0f;               
              while(temp!=0x0f)  
                {  
                  temp=P3;  
                  temp=temp & 0x0f;               
                }  
            }  
        }  
    }  
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