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第一章:硬件资源模块第二章:keilc软件使用
at89s51单片机实验及实践课题     at89s51单片机实验及实践课题
1.闪烁灯2.模拟开关灯
3.多路开关状态指示4.广告灯的左移右移
5.广告灯(利用取表方式)6.报警产生器
7.I/O并行口直接驱动LED显示8.按键识别方法之一
9.一键多功能按键识别技术10.00-99计数器
11.00-59秒计时器(软件延时)12.可预置可逆4位计数器
13.动态数码显示技术14.4×4矩阵式键盘识别技术
15.定时计数器T0作定时(一)16.定时计数器T0作定时应用技术(二)
17.99秒马表设计18.“嘀、嘀、……”报警声
19.“叮咚”门铃20.数字钟(★)
21.拉幕式数码显示技术22.电子琴
23.模拟计算器数字输入及显示24.8×8LED点阵显示技术
25.点阵LED“0-9”数字显示技术26.点阵式LED简单图形显示技术
27.ADC0809A/D转换器基本应用技术28.数字电压表
29.两点间温度控制30.四位数数字温度计
31.6位数显频率计数器32.电子密码锁设计
33.4×4键盘的电子密码锁34.带有存储器功能的数字温度计-DS1624技术应用
35.DS18B20数字温度计使用

单片机c语言集锦<>欢迎进入51单片机学习网论坛讨论

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22.    电子琴

1.  实验任务

(1.       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

4.22.1

3.系统板硬件连线

(1.       把“单片机系统”区域中的P1.0端口用导线连接到“音频放大模块”区域中的SPK IN端口上;

(2.       把“单片机系统“区域中的P3.0P3.7端口用8芯排线连接到“4X4行列式键盘”区域中的C1C4 R1R4端口上;

4.  相关程序内容

(1.       4X4行列式键盘识别;

(2.       音乐产生的方法;

一首音乐是许多不同的音阶组成的,而每个音阶对应着不同的频率,这样我们就可以利用不同的频率的组合,即可构成我们所想要的音乐了,当然对于单片机来产生不同的频率非常方便,我们可以利用单片机的定时/计数器T0来产生这样方波频率信号,因此,我们只要把一首歌曲的音阶对应频率关系弄正确即可。现在以单片机12MHZ晶振为例,例出高中低音符与单片机计数T0相关的计数值如下表所示

音符

频率(HZ

简谱码(T值)

 

音符

频率(HZ

简谱码(T值)

1 DO

262

63628

# 4 FA#

740

64860

#1 DO#

277

63731

5 SO

784

64898

2 RE

294

63835

# 5 SO#

831

64934

#2 RE#

311

63928

6 LA

880

64968

3 M

330

64021

# 6

932

64994

4 FA

349

64103

7 SI

988

65030

# 4 FA#

370

64185

1 DO

1046

65058

5 SO

392

64260

# 1 DO#

1109

65085

# 5 SO#

415

64331

2 RE

1175

65110

6 LA

440

64400

 

# 2 RE#

1245

65134

# 6

466

64463

3 M

1318

65157

7 SI

494

64524

4 FA

1397

65178

1 DO

523

64580

# 4 FA#

1480

65198

# 1 DO#

554

64633

5 SO

1568

65217

2 RE

587

64684

# 5 SO#

1661

65235

# 2 RE#

622

64732

6 LA

1760

65252

3 M

659

64777

# 6

1865

65268

4 FA

698

64820

7 SI

1967

65283

下面我们要为这个音符建立一个表格,有助于单片机通过查表的方式来获得相应的数据

低音019之间,中音在2039之间,高音在4059之间

TABLE:        DW 0,63628,63835,64021,64103,64260,64400,64524,0,0

                   DW 0,63731,63928,0,64185,64331,64463,0,0,0

                   DW 0,64580,64684,64777,64820,64898,64968,65030,0,0

                   DW 0,64633,64732,0,64860,64934,64994,0,0,0

                   DW 0,65058,65110,65157,65178,65217,65252,65283,0,0

                   DW 0,65085,65134,0,65198,65235,65268,0,0,0

                   DW 0

2、音乐的音拍,一个节拍为单位(C调)

曲调值

DELAY

 

曲调值

DELAY

4/4

125ms

 

4/4

62ms

3/4

187ms

 

3/4

94ms

2/4

250ms

 

2/4

125ms

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

 

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 char key;

unsigned char i,j;

unsigned char STH0;

unsigned char STL0;

unsigned int code tab[]={64021,64103,64260,64400,

                          64524,64580,64684,64777,

                          64820,64898,64968,65030,

                          65058,65110,65157,65178};

void main(void)

{

  TMOD=0x01;

  ET0=1;

  EA=1;

  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=0;

                    break;

                  case 0x0d:

                    key=1;

                    break;

                  case 0x0b:

                    key=2;

                    break;

                  case 0x07:

                    key=3;

                    break;

                }

              temp=P3;

              P1_0=~P1_0;

              P0=table[key];

              STH0=tab[key]/256;

              STL0=tab[key]%256;

              TR0=1;

              temp=temp & 0x0f;             

              while(temp!=0x0f)

                {

                  temp=P3;

                  temp=temp & 0x0f;             

                }

              TR0=0;

            }

        }

 

      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=7;

                    break;

                }

              temp=P3;

              P1_0=~P1_0;

              P0=table[key];

              STH0=tab[key]/256;

              STL0=tab[key]%256;

              TR0=1;

              temp=temp & 0x0f;             

              while(temp!=0x0f)

                {

                  temp=P3;

                  temp=temp & 0x0f;             

                }

              TR0=0;

            }

        }

 

      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=8;

                    break;

                  case 0x0d:

                    key=9;

                    break;

                  case 0x0b:

                    key=10;

                    break;

                  case 0x07:

                    key=11;

                    break;

                }

              temp=P3;

              P1_0=~P1_0;

              P0=table[key];

              STH0=tab[key]/256;

              STL0=tab[key]%256;

              TR0=1;

              temp=temp & 0x0f;             

              while(temp!=0x0f)

                {

                  temp=P3;

                  temp=temp & 0x0f;             

                }

              TR0=0;

            }

        }

      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=12;

                    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];

              STH0=tab[key]/256;

              STL0=tab[key]%256;

              TR0=1;

              temp=temp & 0x0f;             

              while(temp!=0x0f)

                {

                  temp=P3;

                  temp=temp & 0x0f;             

                }

              TR0=0;

            }

        }     

    }

}

 

void t0(void) interrupt 1 using 0

{

  TH0=STH0;

  TL0=STL0;

  P1_0=~P1_0;

}