单片机电子琴设计

1．实验任务

（1．由4X4组成16个按钮矩阵，设计成16个音。

（2．可随意弹奏想要表达的音乐。

2．电路原理图

对于不同的曲调我们也可以用单片机的另外一个定时/计数器来完成。

下面就用AT89S51单片机产生一首“生日快乐”歌曲来说明单片机如何产生的。

在这个程序中用到了两个定时/计数器来完成的。其中T0用来产生音符频率，T1用来产生音拍。

5．程序框图

图4.22.2

6．汇编源程序

KEYBUF EQU 30H

STH0 EQU 31H

STL0 EQU 32H

TEMP EQU 33H

ORG 00H

LJMP START

ORG 0BH

LJMP INT_T0

START: MOV TMOD,#01H

SETB ET0

SETB EA

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

MOV A,KEYBUF

MOV B,#2

MUL AB

MOV TEMP,A

MOV DPTR,#TABLE1

MOVC A,@A+DPTR

MOV STH0,A

MOV TH0,A

INC TEMP

MOV A,TEMP

MOVC A,@A+DPTR

MOV STL0,A

MOV TL0,A

SETB TR0

DK1A: MOV A,P3

ANL A,#0FH

XRL A,#0FH

JNZ DK1A

CLR TR0

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

MOV A,KEYBUF

MOV B,#2

MUL AB

MOV TEMP,A

MOV DPTR,#TABLE1

MOVC A,@A+DPTR

MOV STH0,A

MOV TH0,A

INC TEMP

MOV A,TEMP

MOVC A,@A+DPTR

MOV STL0,A

MOV TL0,A

SETB TR0

DK2A: MOV A,P3

ANL A,#0FH

XRL A,#0FH

JNZ DK2A

CLR TR0

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

MOV A,KEYBUF

MOV B,#2

MUL AB

MOV TEMP,A

MOV DPTR,#TABLE1

MOVC A,@A+DPTR

MOV STH0,A

MOV TH0,A

INC TEMP

MOV A,TEMP

MOVC A,@A+DPTR

MOV STL0,A

MOV TL0,A

SETB TR0

DK3A: MOV A,P3

ANL A,#0FH

XRL A,#0FH

JNZ DK3A

CLR TR0

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

MOV A,KEYBUF

MOV B,#2

MUL AB

MOV TEMP,A

MOV DPTR,#TABLE1

MOVC A,@A+DPTR

MOV STH0,A

MOV TH0,A

INC TEMP

MOV A,TEMP

MOVC A,@A+DPTR

MOV STL0,A

MOV TL0,A

SETB TR0

DK4A: MOV A,P3

ANL A,#0FH

XRL A,#0FH

JNZ DK4A

CLR TR0

NOKEY4:

LJMP WAIT

DELY10MS:

MOV R6,#10

D1: MOV R7,#248

DJNZ R7,$

DJNZ R6,D1

RET

INT_T0:

MOV TH0,STH0

MOV TL0,STL0

CPL P1.0

RETI

TABLE: DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H

DB 7FH,6FH,77H,7CH,39H,5EH,79H,71H

TABLE1: DW 64021,64103,64260,64400

DW 64524,64580,64684,64777

DW 64820,64898,64968,65030

DW 65058,65110,65157,65178

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