AT89S51单片机试验及实践教程之电子琴

AT89S51单片机试验及实践教程之电子琴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SPKIN端口上；2．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－C4R1－R4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）低1DO26263628#4FA#74064860#1DO#27763731中5SO78464898低2RE29463835#5SO#83164934#2RE#31163928中6LA88064968低3M33064021#693264994低4FA34964103中7SI98865030#4FA#37064185高1DO104665058低5SO39264260#1DO#110965085#5SO#41564331高2RE117565110低6LA44064400#2RE#124565134#646664463高3M131865157低7SI49464524高4FA139765178中1DO52364580#4FA#148065198#1DO#55464633高5SO156865217中2RE58764684#5SO#166165235#2RE#62264732高6LA176065252中3M65964777#6186565268中4FA69864820高7SI196765283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0－19之间，中音在20－39之间，高音在40－59之间TABLE:DW0,63628,63835,64021,64103,64260,64400,64524,0,0DW0,63731,63928,0,64185,64331,64463,0,0,0DW0,64580,64684,64777,64820,64898,64968,65030,0,0DW0,64633,64732,0,64860,64934,64994,0,0,0DW0,65058,65110,65157,65178,65217,65252,65283,0,0DW0,65085,65134,0,65198,65235,65268,0,0,0DW02、音乐的音拍，一个节拍为单位（C调）曲调值DELAY曲调值DELAY调4/4125ms调4/462ms调3/4187ms调3/494ms调2/4250ms调2/4125ms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6．汇编源程序KEYBUFEQU30HSTH0EQU31HSTL0EQU32HTEMPEQU33HORG00HLJMPSTARTORG0BHLJMPINT_T0START:MOVTMOD,#01HSETBET0SETBEAWAIT:MOVP3,#0FFHCLRP3.4MOVA,P3ANLA,#0FHXRLA,#0FHJZNOKEY1LCALLDELY10MSMOVA,P3ANLA,#0FHXRLA,#0FHJZNOKEY1MOVA,P3ANLA,#0FHCJNEA,#0EH,NK1MOVKEYBUF,#0LJMPDK1NK1:CJNEA,#0DH,NK2MOVKEYBUF,#1LJMPDK1NK2:CJNEA,#0BH,NK3MOVKEYBUF,#2LJMPDK1NK3:CJNEA,#07H,NK4MOVKEYBUF,#3LJMPDK1NK4:NOPDK1:MOVA,KEYBUFMOVDPTR,#TABLEMOVCA,@A+DPTRMOVP0,AMOVA,KEYBUFMOVB,#2MULABMOVTEMP,AMOVDPTR,#TABLE1MOVCA,@A+DPTRMOVSTH0,AMOVTH0,AINCTEMPMOVA,TEMPMOVCA,@A+DPTRMOVSTL0,AMOVTL0,ASETBTR0DK1A:MOVA,P3ANLA,#0FHXRLA,#0FHJNZDK1ACLRTR0NOKEY1:MOVP3,#0FFHCLRP3.5MOVA,P3ANLA,#0FHXRLA,#0FHJZNOKEY2LCALLDELY10MSMOVA,P3ANLA,#0FHXRLA,#0FHJZNOKEY2MOVA,P3ANLA,#0FHCJNEA,#0EH,NK5MOVKEYBUF,#4LJMPDK2NK5:CJNEA,#0DH,NK6MOVKEYBUF,#5LJMPDK2NK6:CJNEA,#0BH,NK7MOVKEYBUF,#6LJMPDK2NK7:CJNEA,#07H,NK8MOVKEYBUF,#7LJMPDK2NK8:NOPDK2:MOVA,KEYBUFMOVDPTR,#TABLEMOVCA,@A+DPTRMOVP0,AMOVA,KEYBUFMOVB,#2MULABMOVTEMP,AMOVDPTR,#TABLE1MOVCA,@A+DPTRMOVSTH0,AMOVTH0,AINCTEMPMOVA,TEMPMOVCA,@A+DPTRMOVSTL0,AMOVTL0,ASETBTR0DK2A:MOVA,P3ANLA,#0FHXRLA,#0FHJNZDK2ACLRTR0NOKEY2:MOVP3,#0FFHCLRP3.6MOVA,P3ANLA,#0FHXRLA,#0FHJZNOKEY3LCALLDELY10MSMOVA,P3ANLA,#0FHXRLA,#0FHJZNOKEY3MOVA,P3ANLA,#0FHCJNEA,#0EH,NK9MOVKEYBUF,#8LJMPDK3NK9:CJNEA,#0DH,NK10MOVKEYBUF,#9LJMPDK3NK10:CJNEA,#0BH,NK11MOVKEYBUF,#10LJMPDK3NK11:CJNEA,#07H,NK12MOVKEYBUF,#11LJMPDK3NK12:NOPDK3:MOVA,KEYBUFMOVDPTR,#TABLEMOVCA,@A+DPTRMOVP0,AMOVA,KEYBUFMOVB,#2MULABMOVTEMP,AMOVDPTR,#TABLE1MOVCA,@A+DPTRMOVSTH0,AMOVTH0,AINCTEMPMOVA,TEMPMOVCA,@A+DPTRMOVSTL0,AMOVTL0,ASETBTR0DK3A:MOVA,P3ANLA,#0FHXRLA,#0FHJNZDK3ACLRTR0NOKEY3:MOVP3,#0FFHCLRP3.7MOVA,P3ANLA,#0FHXRLA,#0FHJZNOKEY4LCALLDELY10MSMOVA,P3ANLA,#0FHXRLA,#0FHJZNOKEY4MOVA,P3ANLA,#0FHCJNEA,#0EH,NK13MOVKEYBUF,#12LJMPDK4NK13:CJNEA,#0DH,NK14MOVKEYBUF,#13LJMPDK4NK14:CJNEA,#0BH,NK15MOVKEYBUF,#14LJMPDK4NK15:CJNEA,#07H,NK16MOVKEYBUF,#15LJMPDK4NK16:NOPDK4:MOVA,KEYBUFMOVDPTR,#TABLEMOVCA,@A+DPTRMOVP0,AMOVA,KEYBUFMOVB,#2MULABMOVTEMP,AMOVDPTR,#TABLE1MOVCA,@A+DPTRMOVSTH0,AMOVTH0,AINCTEMPMOVA,TEMPMOVCA,@A+DPTRMOVSTL0,AMOVTL0,ASETBTR0DK4A:MOVA,P3ANLA,#0FHXRLA,#0FHJNZDK4ACLRTR0NOKEY4:LJMPWAITDELY10MS:MOVR6,#10D1:MOVR7,#248DJNZR7,$DJNZR6,D1RETINT_T0:MOVTH0,STH0MOVTL0,STL0CPLP1.0RETITABLE:DB3FH,06H,5BH,4FH,66H,6DH,7DH,07HDB7FH,6FH,77H,7CH,39H,5EH,79H,71HTABLE1:DW64021,64103,64260,64400DW64524,64580,64684,64777DW64820,64898,64968,65030DW65058,65110,65157,65178END7．C语言源程序＃includeAT89X51.Hunsignedcharcodetable[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};unsignedchartemp;unsignedcharkey;unsignedchari,j;unsignedcharSTH0;unsignedcharSTL0;unsignedintcodetab[]={64021,64103,64260,64400,64524,64580,64684,64777,64820,64898,64968,65030,65058,65110,65157,65178};voidmain(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;i0;i--)for(j=200;j0;j--);temp=P3;temp=temp&0x0f;if(temp!=0x0f){temp=P3;temp=temp&0x0f;switch(temp){case0x0e:key=0;break;case0x0d:key=1;break;case0x0b:key=2;break;case0x07: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;i0;i--)for(j=200;j0;j--);temp=P3;temp=temp&0x0f;if(temp!=0x0f){temp=P3;temp=temp&0x0f;switch(temp){case0x0e:key=4;break;case0x0d:key=5;break;case0x0b:key=6;break;case0x07: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;