|
- UID
- 852722
|
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;
}
}
}
}
} |
|
