-.z.實驗三-利用蜂鳴器演奏音樂一、實驗?zāi)康?.了解BlueSkyC51單片機實驗板中蜂鳴器的硬件電路2.學(xué)會利用蜂鳴器實現(xiàn)音樂的演奏3.掌握蜂鳴器實現(xiàn)音樂演奏的編程二、實驗硬件設(shè)計及電路1.BlueSkyC51單片機實驗板2.單片機最小系統(tǒng)3.蜂鳴器電路連接三極管主要是做驅(qū)動用的。因為單片機的IO口驅(qū)動能力不夠讓蜂鳴器發(fā)出聲音，所以我們通過三極管放大驅(qū)動電流，從而可以讓蜂鳴器發(fā)出聲音，你要是輸出高電平，三極管導(dǎo)通，集電極電流通過蜂鳴器讓蜂鳴器發(fā)出聲音，當輸出低電平時，三極管截止，沒有電流流過蜂鳴器，所以就不會發(fā)出聲音。三、實驗原理1.音調(diào)及節(jié)拍用一個口，輸出方波，這個方波輸入進蜂鳴器就會產(chǎn)生聲音，通過控制方波的頻率、時間，就能產(chǎn)生簡單的音樂。一般說來，單片機演奏音樂基本都是單音頻率，因此單片機奏樂只需控制音調(diào)和節(jié)拍。（1）音調(diào)的確定音調(diào)是由頻率來確定的。通過單片機的定時器定時中斷，將單片機上對應(yīng)蜂鳴器的I/O口來回取反，從而讓蜂鳴器發(fā)出不同頻率的聲音。只需將定時器給以不同的定時值就可實現(xiàn)。通過延時，即可發(fā)出所需要的頻率。（2）節(jié)拍的確定一拍的時長大約為400—500ms,每個音符的時長通過節(jié)拍來計算。詳細見程序代碼。2.軟件設(shè)計相關(guān)（1）頭文件#include<reg51.h>#defineuintunsignedint#defineucharunsignedchar#defineulongunsignedlongsbitbeep=P1^4;//蜂鳴器與P1.4口連接(2)歌曲曲譜ucharcodediaodata[30]={//音調(diào)代碼0*10,0*0e,0*0c,0*10,0*0e,0*0c,0*10,0*0e,0*10,0*0c,0*10,0*15,0*13,0*10,0*13,0*15,0*15,0*13,0*15,0*13,0*10,0*0e,0*0c,0*0e,0*0e,0*10,0*0e,0*0c,0*0e,0*00};ucharcodejiedata[30]={//音長代碼0*04,0*04,0*08,0*06,0*02,0*08,0*04,0*04,0*04,0*04,0*02,0*06,0*08,0*02,0*02,0*04,0*04,0*04,0*04,0*08,0*02,0*02,0*04,0*04,0*02,0*02,0*04,0*04,0*0c,0*00};(3)音階表ucharcodefreq[36*2]={//音階碼表0*f7,0*d8,//440hz,1//00*f8,0*50,//466hz,1#//10*f8,0*bc,//494hz,2//20*f9,0*26,//524hz,2#//30*f9,0*85,//554hz,3//40*f9,0*e5,//588hz,4//50*fa,0*3d,//622hz,4#//60*fa,0*92,//660hz,5//70*fa,0*dd,//698hz,5#//80*fb,0*29,//740hz,6//90*fb,0*70,//784hz,6#//100*fb,0*b0,//830hz,7//110*fb,0*ef,//880hz,1//120*fc,0*29,//932hz,1#//130*fc,0*62,//988hz,2//140*fc,0*95,//1046hz,2#//150*fc,0*c7,//1108hz,3//160*fc,0*f5,//1174hz,4//170*fd,0*20,//1244hz,4#//180*fd,0*4c,//1318hz,5//190*fd,0*72,//1396hz,5#//200*fd,0*97,//1480hz,6//210*fd,0*bb,//1568hz,6#//220*fd,0*dc,//1662hz,7//230*fd,0*fb,//1769hz,`1//240*fe,0*18,//1864hz,`1#//250*fe,0*34,//1976hz,`2//260*fe,0*4e,//2092hz,`2#//270*fe,0*67,//2218hz,`3//280*fe,0*7d,//2350hz,`4//290*fe,0*94,//2488hz,`4#//300*fe,0*a8,//2639hz,`5//310*fe,0*bc,//2794hz,`5#//320*fe,0*cf,//2960hz,`6//330*fe,0*e0,//3136hz,`6#//340*fe,0*f1,//3322hz,`7//35};(4)音符發(fā)生程序（中斷服務(wù)程序）voidtimer0()interrupt1//用于產(chǎn)生音符的T0中斷服務(wù)程序{TH0=th0_f;TL0=tl0_f;beep=~beep;//取反beep引腳，發(fā)聲}三、實驗過程及問題1.Keil開發(fā)過程(1)新建"Project”，選擇單片機為"AT89C52”(2)新建c文件"music.c”，并添加到工程中(3)設(shè)置生成"HE*”文件，編譯(4)將生成的"HE*”文件燒錄到單片機，檢驗(5)不斷修改完善2.編譯實驗相關(guān)問題(1)實際發(fā)音顫音重解決方法為修改蜂鳴器的驅(qū)動頻率.(2)實際節(jié)奏過快或者過慢調(diào)整延時四、C51程序代碼（部分來源于網(wǎng)絡(luò)）#include<reg51.h>#defineuintunsignedint#defineucharunsignedchar#defineulongunsignedlongsbitbeep=P1^4;//蜂鳴器與P1.4口連接ucharth0_f;//中斷裝載T0高8位uchartl0_f;//T0低8位ucharcodefreq[36*2]={//音階碼表0*f7,0*d8,//440hz,1//00*f8,0*50,//466hz,1#//10*f8,0*bc,//494hz,2//20*f9,0*26,//524hz,2#//30*f9,0*85,//554hz,3//40*f9,0*e5,//588hz,4//50*fa,0*3d,//622hz,4#//60*fa,0*92,//660hz,5//70*fa,0*dd,//698hz,5#//80*fb,0*29,//740hz,6//90*fb,0*70,//784hz,6#//100*fb,0*b0,//830hz,7//110*fb,0*ef,//880hz,1//120*fc,0*29,//932hz,1#//130*fc,0*62,//988hz,2//140*fc,0*95,//1046hz,2#//150*fc,0*c7,//1108hz,3//160*fc,0*f5,//1174hz,4//170*fd,0*20,//1244hz,4#//180*fd,0*4c,//1318hz,5//190*fd,0*72,//1396hz,5#//200*fd,0*97,//1480hz,6//210*fd,0*bb,//1568hz,6#//220*fd,0*dc,//1662hz,7//230*fd,0*fb,//1769hz,`1//240*fe,0*18,//1864hz,`1#//250*fe,0*34,//1976hz,`2//260*fe,0*4e,//2092hz,`2#//270*fe,0*67,//2218hz,`3//280*fe,0*7d,//2350hz,`4//290*fe,0*94,//2488hz,`4#//300*fe,0*a8,//2639hz,`5//310*fe,0*bc,//2794hz,`5#//320*fe,0*cf,//2960hz,`6//330*fe,0*e0,//3136hz,`6#//340*fe,0*f1,//3322hz,`7//35};ucharcodediaodata[30]={//音調(diào)代碼0*10,0*0e,0*0c,0*10,0*0e,0*0c,0*10,0*0e,0*10,0*0c,0*10,0*15,0*13,0*10,0*13,0*15,0*15,0*13,0*15,0*13,0*10,0*0e,0*0c,0*0e,0*0e,0*10,0*0e,0*0c,0*0e,0*00};ucharcodejiedata[30]={//音長代碼0*04,0*04,0*08,0*06,0*02,0*08,0*04,0*04,0*04,0*04,0*02,0*06,0*08,0*02,0*02,0*04,0*04,0*04,0*04,0*08,0*02,0*02,0*04,0*04,0*02,0*02,0*04,0*04,0*0c,0*00};voidtimer0()interrupt1//用于產(chǎn)生音符的T0中斷服務(wù)程序{TH0=th0_f;TL0=tl0_f;beep=~beep;//取反beep引腳，發(fā)聲}voidmain(void){uchari,j,k=0;uintn;TMOD=0*01;//T0方式1TR0=0;//關(guān)閉T0（不發(fā)聲）ET0=1;//允許T0中斷EA=1;//允許總中斷while(1){TR0=1;//開T0for(i=0;diaodata[i]!=0;i++){