單片機數字音樂盒制作proteus仿真原理圖：
 
單片機源程序：
- #include<reg51.h>
- #define uchar unsigned char
- #define uchar unsigned char
- #define uint unsigned int
- #define LCDPORT P0
- uchar code tab[]="Press key";
- uchar code tab1[]="Select song";
- uchar code tab2[]="First Song" ;
- uchar code tab3[]="butterfly";
- uchar code tab4[]="Second Song" ;
- uchar code tab5[]="Jingle bell ";
- uchar code tab6[]="Third Song" ;
- uchar code tab7[]="Yesterday";
- uchar code tab8[]="Forth Song" ;
- uchar code tab9[]="Youth League";
- sbit LCDE=P2^2;
- sbit LCDRW=P2^1;
- sbit LCDRS=P2^0;
- #define SYSTEM_OSC 12000000 //定義晶振頻率12000000HZ
- #define SOUND_SPACE 4/5 //定義普通音符演奏的長度分率,//每4分音符間隔
- sbit BeepIO = P3^7; //定義輸出管腳
- sbit K1=P1^7;
- unsigned int code FreTab[12] = { 262,277,294,311,330,349,369,392,415,440,466,494 }; //原始頻率表
- unsigned char code SignTab[7] = { 0,2,4,5,7,9,11 }; //1~7在頻率表中的位置
- unsigned char code LengthTab[7]= { 1,2,4,8,16,32,64 };
- unsigned char Sound_Temp_TH0,Sound_Temp_TL0; //音符定時器初值暫存
- unsigned char Sound_Temp_TH1,Sound_Temp_TL1;
- unsigned char code Music_Girl[]=
- { 0x1B,0x02, 0x1A,0x02, 0x1B,0x02, 0x19,0x66, 0x1A,0x03,
- 0x18,0x02, 0x17,0x02, 0x16,0x0D, 0x17,0x03, 0x18,0x0D,
- 0x17,0x03, 0x19,0x66, 0x17,0x03, 0x16,0x0D, 0x17,0x03,
- 0x19,0x0D, 0x16,0x03, 0x17,0x0D, 0x18,0x03, 0x17,0x0D,
- 0x16,0x03, 0x15,0x00, 0x19,0x02, 0x11,0x02, 0x16,0x02,
- 0x10,0x02, 0x15,0x02, 0x0F,0x00, 0x10,0x03, 0x15,0x03,
- 0x0F,0x00, 0x0D,0x01, 0x0F,0x66, 0x10,0x03, 0x15,0x66,
- 0x16,0x03, 0x10,0x0D, 0x15,0x03, 0x0F,0x03, 0x19,0x66,
- 0x1F,0x03, 0x1A,0x0D, 0x19,0x03, 0x17,0x03, 0x19,0x03,
- 0x16,0x00, 0x16,0x66, 0x17,0x03, 0x11,0x0C, 0x10,0x02,
- 0x19,0x66, 0x10,0x03, 0x15,0x02, 0x16,0x02, 0x0D,0x02,
- 0x15,0x02, 0x10,0x0D, 0x0F,0x03, 0x10,0x0D, 0x15,0x03,
- 0x0F,0x00, 0x17,0x66, 0x19,0x03, 0x11,0x02, 0x16,0x02,
- 0x10,0x0D, 0x15,0x03, 0x0F,0x15, 0x0D,0x03, 0x0F,0x02,
- 0x0D,0x03, 0x0F,0x0D, 0x10,0x03, 0x11,0x0D, 0x16,0x03,
- 0x10,0x00, 0x0F,0x0D, 0x10,0x03, 0x15,0x66, 0x16,0x03,
- 0x19,0x02, 0x17,0x02, 0x16,0x02, 0x17,0x0D, 0x16,0x03,
- 0x15,0x02, 0x10,0x0D, 0x0F,0x03, 0x0D,0x01, 0x15,0x01,
- 0x10,0x03, 0x15,0x04, 0x10,0x0D, 0x0F,0x03, 0x0D,0x0D,
- 0x0F,0x03, 0x10,0x0D, 0x15,0x03, 0x0F,0x00, 0x17,0x0D,
- 0x19,0x03, 0x16,0x0D, 0x17,0x03, 0x16,0x0D, 0x15,0x03,
- 0x11,0x02, 0x10,0x02, 0x0F,0x00, 0x00,0x00 };
- unsigned char code Music_Jingle[]={
- 0x0F,0x03, 0x0F,0x03, 0x17,0x03, 0x16,0x03, 0x15,0x03,
- 0x0F,0x66, 0x19,0x04, 0x19,0x04, 0x0F,0x03, 0x17,0x03,
- 0x16,0x03, 0x15,0x03, 0x10,0x02, 0x10,0x03, 0x10,0x03,
- 0x18,0x03, 0x17,0x03, 0x16,0x03, 0x10,0x66, 0x10,0x03,
- 0x19,0x03, 0x19,0x03, 0x18,0x03, 0x16,0x03, 0x17,0x02,
- 0x15,0x03, 0x0F,0x03, 0x0F,0x03, 0x17,0x03, 0x16,0x03,
- 0x15,0x03, 0x0F,0x66, 0x0F,0x03, 0x0F,0x03, 0x17,0x03,
- 0x16,0x03, 0x15,0x03, 0x10,0x66, 0x10,0x03, 0x10,0x03,
- 0x18,0x03, 0x17,0x03, 0x16,0x03, 0x19,0x03, 0x19,0x03,
- 0x19,0x03, 0x19,0x03, 0x1A,0x03, 0x19,0x03, 0x18,0x03,
- 0x16,0x03, 0x15,0x66, 0x17,0x03, 0x17,0x03, 0x17,0x02,
- 0x17,0x03, 0x17,0x03, 0x17,0x02, 0x17,0x03, 0x19,0x03,
- 0x15,0x03, 0x16,0x03, 0x17,0x01, 0x18,0x03, 0x18,0x03,
- 0x18,0x67, 0x18,0x04, 0x18,0x03, 0x17,0x03, 0x17,0x03,
- 0x17,0x04, 0x17,0x04, 0x17,0x03, 0x16,0x03, 0x16,0x03,
- 0x15,0x03, 0x16,0x03, 0x19,0x66, 0x19,0x03, 0x19,0x03,
- 0x18,0x03, 0x16,0x03, 0x15,0x02, 0x00,0x00 };
- unsigned char code Music_Two[] ={
- 0x17,0x03, 0x16,0x03, 0x17,0x01, 0x16,0x03, 0x17,0x03,
- 0x16,0x03, 0x15,0x01, 0x10,0x03, 0x15,0x03, 0x16,0x02,
- 0x16,0x0D, 0x17,0x03, 0x16,0x03, 0x15,0x03, 0x10,0x03,
- 0x10,0x0E, 0x15,0x04, 0x0F,0x01, 0x17,0x03, 0x16,0x03,
- 0x17,0x01, 0x16,0x03, 0x17,0x03, 0x16,0x03, 0x15,0x01,
- 0x10,0x03, 0x15,0x03, 0x16,0x02, 0x16,0x0D, 0x17,0x03,
- 0x16,0x03, 0x15,0x03, 0x10,0x03, 0x15,0x03, 0x16,0x01,
- 0x17,0x03, 0x16,0x03, 0x17,0x01, 0x16,0x03, 0x17,0x03,
- 0x16,0x03, 0x15,0x01, 0x10,0x03, 0x15,0x03, 0x16,0x02,
- 0x16,0x0D, 0x17,0x03, 0x16,0x03, 0x15,0x03, 0x10,0x03,
- 0x10,0x0E, 0x15,0x04, 0x0F,0x01, 0x17,0x03, 0x19,0x03,
- 0x19,0x01, 0x19,0x03, 0x1A,0x03, 0x19,0x03, 0x17,0x01,
- 0x16,0x03, 0x16,0x03, 0x16,0x02, 0x16,0x0D, 0x17,0x03,
- 0x16,0x03, 0x15,0x03, 0x10,0x03, 0x10,0x0D, 0x15,0x00,
- 0x19,0x03, 0x19,0x03, 0x1A,0x03, 0x1F,0x03, 0x1B,0x03,
- 0x1B,0x03, 0x1A,0x03, 0x17,0x0D, 0x16,0x03, 0x16,0x03,
- 0x16,0x0D, 0x17,0x01, 0x17,0x03, 0x17,0x03, 0x19,0x03,
- 0x1A,0x02, 0x1A,0x02, 0x10,0x03, 0x17,0x0D, 0x16,0x03,
- 0x16,0x01, 0x17,0x03, 0x19,0x03, 0x19,0x03, 0x17,0x03,
- 0x19,0x02, 0x1F,0x02, 0x1B,0x03, 0x1A,0x03, 0x1A,0x0E,
- 0x1B,0x04, 0x17,0x02, 0x1A,0x03, 0x1A,0x03, 0x1A,0x0E,
- 0x1B,0x04, 0x1A,0x03, 0x19,0x03, 0x17,0x03, 0x16,0x03,
- 0x17,0x0D, 0x16,0x03, 0x17,0x03, 0x19,0x01, 0x19,0x03,
- 0x19,0x03, 0x1A,0x03, 0x1F,0x03, 0x1B,0x03, 0x1B,0x03,
- 0x1A,0x03, 0x17,0x0D, 0x16,0x03, 0x16,0x03, 0x16,0x03,
- 0x17,0x01, 0x17,0x03, 0x17,0x03, 0x19,0x03, 0x1A,0x02,
- 0x1A,0x02, 0x10,0x03, 0x17,0x0D, 0x16,0x03, 0x16,0x01,
- 0x17,0x03, 0x19,0x03, 0x19,0x03, 0x17,0x03, 0x19,0x03,
- 0x1F,0x02, 0x1B,0x03, 0x1A,0x03, 0x1A,0x0E, 0x1B,0x04,
- 0x17,0x02, 0x1A,0x03, 0x1A,0x03, 0x1A,0x0E, 0x1B,0x04,
- 0x17,0x16, 0x1A,0x03, 0x1A,0x03, 0x1A,0x0E, 0x1B,0x04,
- 0x1A,0x03, 0x19,0x03, 0x17,0x03, 0x16,0x03, 0x0F,0x02,
- 0x10,0x03, 0x15,0x00, 0x00,0x00 };
- unsigned char code Music_Yesterday[]={
- 0x15,0x03, 0x15,0x03, 0x16,0x03, 0x17,0x02, 0x19,0x02,
- 0x19,0x03, 0x17,0x03, 0x19,0x03, 0x17,0x03, 0x1A,0x02,
- 0x19,0x66, 0x17,0x02, 0x17,0x03, 0x19,0x03, 0x1A,0x02,
- 0x16,0x02, 0x17,0x03, 0x19,0x02, 0x1A,0x15, 0x17,0x03,
- 0x19,0x03, 0x1A,0x02, 0x21,0x02, 0x20,0x03, 0x1F,0x02,
- 0x1B,0x03, 0x1B,0x66, 0x19,0x03, 0x17,0x03, 0x19,0x02,
- 0x17,0x02, 0x16,0x14, 0x15,0x03, 0x15,0x03, 0x16,0x03,
- 0x17,0x03, 0x19,0x02, 0x19,0x03, 0x19,0x03, 0x17,0x03,
- 0x19,0x03, 0x17,0x03, 0x1A,0x03, 0x19,0x02, 0x17,0x03,
- 0x17,0x02, 0x17,0x03, 0x19,0x03, 0x1A,0x02, 0x1B,0x02,
- 0x17,0x03, 0x19,0x02, 0x1A,0x03, 0x1A,0x01, 0x1B,0x02,
- 0x20,0x02, 0x1F,0x03, 0x1B,0x03, 0x1A,0x66, 0x1B,0x03,
- 0x1F,0x03, 0x1B,0x03, 0x1F,0x03, 0x1B,0x02, 0x1A,0x66,
- 0x1A,0x03, 0x1B,0x03, 0x1F,0x02, 0x1F,0x02, 0x1A,0x03,
- 0x1F,0x02, 0x20,0x03, 0x20,0x16, 0x1F,0x02, 0x20,0x02,
- 0x21,0x03, 0x21,0x03, 0x21,0x03, 0x21,0x02, 0x20,0x03,
- 0x1F,0x03, 0x1B,0x03, 0x1F,0x03, 0x1B,0x03, 0x1A,0x66,
- 0x17,0x03, 0x19,0x03, 0x19,0x14, 0x1F,0x03, 0x20,0x03,
- 0x21,0x03, 0x21,0x03, 0x21,0x03, 0x21,0x03, 0x21,0x02,
- 0x20,0x03, 0x1F,0x03, 0x1F,0x03, 0x1B,0x03, 0x1A,0x66,
- 0x17,0x03, 0x19,0x03, 0x19,0x14, 0x1A,0x03, 0x1B,0x03,
- 0x1F,0x03, 0x1B,0x03, 0x1F,0x03, 0x1B,0x03, 0x1F,0x03,
- 0x20,0x66, 0x1F,0x03, 0x1B,0x03, 0x1F,0x03, 0x1B,0x02,
- 0x1F,0x03, 0x20,0x66, 0x1F,0x03, 0x20,0x03, 0x21,0x02,
- 0x21,0x02, 0x20,0x03, 0x1F,0x02, 0x1A,0x03, 0x1A,0x02,
- 0x17,0x02, 0x17,0x03, 0x1A,0x03, 0x17,0x03, 0x19,0x03,
- 0x19,0x14, 0x17,0x03, 0x17,0x03, 0x16,0x04, 0x15,0x04,
- 0x15,0x03, 0x16,0x03, 0x17,0x01, 0x17,0x03, 0x18,0x02,
- 0x16,0x03, 0x16,0x14, 0x17,0x03, 0x17,0x03, 0x17,0x03,
- 0x18,0x02, 0x16,0x03, 0x16,0x16, 0x15,0x03, 0x16,0x03,
- 0x17,0x03, 0x16,0x01, 0x1F,0x02, 0x20,0x02, 0x21,0x03,
- 0x21,0x03, 0x21,0x03, 0x21,0x02, 0x20,0x03, 0x1F,0x03,
- 0x1B,0x03, 0x1F,0x03, 0x1B,0x03, 0x1A,0x03, 0x1A,0x02,
- 0x17,0x03, 0x19,0x03, 0x19,0x14, 0x1F,0x02, 0x20,0x02,
- 0x21,0x03, 0x21,0x03, 0x21,0x03, 0x21,0x66, 0x20,0x03,
- 0x1F,0x03, 0x1B,0x03, 0x1F,0x03, 0x1B,0x03, 0x1A,0x66,
- 0x17,0x03, 0x19,0x03, 0x19,0x00, 0x00,0x00 };
- uchar k;
- void delay1(void) //延時程序
- {
- uchar i,j;
- for(i=20;i>0;i--)
- for(j=248;j>0;j--);
- }
- void Getch ( )
- { uchar X,Y,Z;
- P1=0xff;
- P1=0xf3; //先對P0置數 行掃描
- if(P1!=0xf3) //判斷是否有鍵按下
- { delay1(); //延時,軟件去干擾
- if(P1!=0xf3) //確認按鍵按下X = P3;
- {
- X=P1; //保存行掃描時有鍵按下時狀態
- P1=0xfc; //列掃描
- Y=P1; //保存列掃描時有鍵按下時狀態
- Z=X|Y;
- //取出鍵值
- switch ( Z ) //判斷鍵值（那一個鍵按下）
- {
- case 0xf9: k=0; break; //對鍵值賦值
- case 0xf5: k=1; break;
- case 0xfa: k=2; break;
- case 0xf6: k=3; break;
- }
- }
- }
- }
- void Delay()
- { uint uiCount;
- for(uiCount=0;uiCount<250;uiCount++);
- }
- void WriteCMD(uchar Commond)//LCD寫指令函數
- {
- Delay(); //先延時。
- LCDE=1; //然后把ＬＣＤ改為寫入命令狀態。
- LCDRS=0;
- LCDRW=0;
- LCDPORT=Commond; //再輸出命令。
- LCDE=0; //最后執行命令。
- }
- void WriteData(uchar dat)//ＬＣＤ寫數據函數
- { Delay(); //先延時。
- LCDE=1; //然后把ＬＣＤ改為寫入數據狀態。
- LCDRS=1;
- LCDRW=0;
- LCDPORT=dat; //再輸出數據。
- LCDE=0; //最后顯示數據。
- }
- void init()
- {
- LCDRW=0;
- LCDE=0;
- WriteCMD(0x38);
- WriteCMD(0x0c);
- WriteCMD(0x06);
- WriteCMD(0x01);
- WriteCMD(0x80);
- }
- void mydelay(int x)
- { int i,j;
- for(i=x;i>0;i--)
- for(j=255;j>0;j--);
- }
- void InitialSound(void)
- {
- BeepIO = 0;
- Sound_Temp_TH1 = (65535-(1/1200)*SYSTEM_OSC)/256; // 計算TL1應裝入的初值 (10ms的初裝值)
- Sound_Temp_TL1 = (65535-(1/1200)*SYSTEM_OSC)%256; // 計算TH1應裝入的初值
- TH1 = Sound_Temp_TH1;
- TL1 = Sound_Temp_TL1;
- TMOD |= 0x11;
- ET0 = 1;
- ET1 = 0;
- TR0 = 0;
- TR1 = 0;
- EA = 1;
- }
- void BeepTimer0(void) interrupt 1 //音符發生中斷
- {
- BeepIO = !BeepIO;
- TH0 = Sound_Temp_TH0;
- TL0 = Sound_Temp_TL0;
- }
- void Play(unsigned char *Sound,unsigned char Signature,unsigned Octachord,unsigned int Speed)
- {
- unsigned int NewFreTab[12]; //新的頻率表
- unsigned char i,j;
- unsigned int Point,LDiv,LDiv0,LDiv1,LDiv2,LDiv4,CurrentFre,Temp_T,SoundLength;
- unsigned char Tone,Length,SL,SH,SM,SLen,XG,FD;
- for(i=0;i<12;i++) // 根據調號及升降八度來生成新的頻率表
- {
- j = i + Signature;
- if(j > 11)
- {
- j = j-12;
- NewFreTab = FreTab[j]*2;
- }
- else
- NewFreTab = FreTab[j];
- if(Octachord == 1)
- NewFreTab>>=2;
- else if(Octachord == 3)
- NewFreTab<<=2;
- }
- SoundLength = 0;
- while(Sound[SoundLength] != 0x00) //計算歌曲長度
- {
- SoundLength+=2;
- }
- Point = 0;
- Tone = Sound[Point];
- Length = Sound[Point+1]; // 讀出第一個音符和它時時值
- LDiv0 = 12000/Speed; // 算出1分音符的長度(幾個10ms)
- LDiv4 = LDiv0/4; // 算出4分音符的長度
- LDiv4 = LDiv4-LDiv4*SOUND_SPACE; // 普通音最長間隔標準
- TR0 = 0;
- TR1 = 1;
- while(Point < SoundLength&&K1==1) //歌曲代碼未放完且暫停鍵未被按下
- {
- SL=Tone%10; //計算出音符
- SM=Tone/10%10; //計算出高低音
- SH=Tone/100; //計算出是否升半
- CurrentFre = NewFreTab[SignTab[SL-1]+SH]; //查出對應音符的頻率
- if(SL!=0)
- {
- if (SM==1) CurrentFre >>= 2; //低音
- if (SM==3) CurrentFre <<= 2; //高音
- Temp_T = 65536-(50000/CurrentFre)*10/(12000000/SYSTEM_OSC);//計算計數器初值
- Sound_Temp_TH0 = Temp_T/256;
- Sound_Temp_TL0 = Temp_T%256;
- TH0 = Sound_Temp_TH0;
- TL0 = Sound_Temp_TL0 + 12; //加12是對中斷延時的補償
- }
- SLen=LengthTab[Length%10]; //算出是幾分音符
- XG=Length/10%10; //算出音符類型(0普通1連音2頓音)
- FD=Length/100;
- LDiv=LDiv0/SLen; //算出連音音符演奏的長度(多少個10ms)
- if (FD==1)
- LDiv=LDiv+LDiv/2;
- if(XG!=1)
- if(XG==0) //算出普通音符的演奏長度
- if (SLen<=4)
- LDiv1=LDiv-LDiv4;
- else
- LDiv1=LDiv*SOUND_SPACE;
- else
- LDiv1=LDiv/2; //算出頓音的演奏長度
- else
- LDiv1=LDiv;
- if(SL==0) LDiv1=0;
- LDiv2=LDiv-LDiv1; //算出不發音的長度
- if (SL!=0)
- {
- TR0=1;
- for(i=LDiv1;i>0;i--) //發規定長度的音
- {
- while(TF1==0);
- TH1 = Sound_Temp_TH1;
- TL1 = Sound_Temp_TL1;
- TF1=0;
- }
- }
- if(LDiv2!=0)
- {
- TR0=0; BeepIO=0;
- for(i=LDiv2;i>0;i--) //音符間的間隔
- {
- while(TF1==0);
- TH1 = Sound_Temp_TH1;
- TL1 = Sound_Temp_TL1;
- TF1=0;
- }
- }
- Point+=2;
- Tone=Sound[Point];
- Length=Sound[Point+1];
- }
- BeepIO = 0;
- }
- main()
- { uint i;
- k=8;
- init();
- for(i=0;i<15;i++)
- {
- WriteData(tab); //LCD寫數據函數寫第一行
- mydelay(50);
- }
- mydelay(1000);
- WriteCMD(0x80+0x40+2); //將指針設到第二行空兩字符
- for(i=0;i<6;i++)
- {
- WriteData(tab1);
- mydelay(50);
- }
- InitialSound(); //發音初始化程序
- while(1)
- { Getch(); //掃描鍵盤，獲得鍵值
- if(k==0) //若鍵值為0
- { uint i;
- init();
- for(i=0;i<10;i++)
- {
- WriteData(tab2); //寫第一首歌序號
- mydelay(50);
- }
- mydelay(1000);
- WriteCMD(0x80+0x40); //轉到第二行
- for(i=0;i<9;i++)
- { WriteData(tab3); //寫歌名
- mydelay(50);
- }
- Play(Music_Girl,0,3,360); //播放第一首歌
- mydelay(500);
- break;
- }
- else if (k==1) //若鍵值為1
- { uint i;
- init();
- for(i=0;i<11;i++)
- { WriteData(tab4); //寫第二首歌序號
- mydelay(50);
- }
- mydelay(1000);
- WriteCMD(0x80+0x40); //轉到第二行
- for(i=0;i<11;i++)
- {
- WriteData(tab5); //寫歌名
- mydelay(50);
- }
- Play(Music_Jingle,0,3,360); //播放第二首歌
- mydelay(500);
- break;
- }
- else if (k==2) //若鍵值為2
- { uint i;
- init();
- for(i=0;i<10;i++)
- { WriteData(tab6); //寫第三首歌序號
- mydelay(50);
- }
- mydelay(1000);
- //WriteCMD(0x01);
- WriteCMD(0x80+0x40); //轉到第二行
- for(i=0;i<6;i++)
- {
- WriteData(tab7); //寫歌名
- mydelay(50);
- }
- Play(Music_Two,0,3,360); //播放第三首歌
- mydelay(500);
1 概述
傳統的音樂盒多是機械音樂盒，其工作原理是通過齒輪帶動一個帶有鐵釘的鐵桶轉動,鐵桶上的鐵釘撞擊鐵片制成的琴鍵，從而發出聲音。但是，機械式的音樂盒體積比較大，比較笨重，且發音單調。水、灰塵等外在因素，容易使內部金屬發音條變形，從而造成發音跑調。另外，機械音樂盒放音時為了讓音色穩定,必須放平不能動搖，而且價格昂貴，不能實現大批量生產。基于單片機設計制作的電子式音樂盒。與傳統的機械式音樂盒相比更小巧，音質更優美且能演奏和弦音樂。電子式音樂盒動力來源是電池，制作工藝簡單，可進行批量生產，所以價格便宜。基于單片機制作的電子式音樂盒，控制功能強大，可根據需要選歌，使用方便。所放歌曲的節奏可以根據需要進行設置，根據存儲容量的大小，可以盡可能多的存儲歌曲。另外，可以設計彩燈外觀效果，增設放歌時間、序號顯示燈功能，使音樂盒的功能更加豐富。
1.1單片機數字音樂盒有關介紹 電子音樂已廣泛地應用于社會生活的各個領域。其類型從音樂卡片到CD、MP3 等多種多樣，制作原理也各不相同。聲音是通過振動產生的。單片機對某一I/O引腳以一定的頻率循環置1和清0，這一引腳便產生一定頻率的方波，該方波通過放大后作用于揚聲器便產生一定頻率的聲音。若改變輸出方波的頻率，產生的聲音也就改變了。通過控制輸出方波的時間長短,聲音的長短也就得到控制。因此，根據樂譜，單片機就可產生電子音樂。音樂中最關鍵的兩個要素是音符和節拍。單片機控制的音樂發生器系統由硬件電路和軟件兩部分構成。利用單片機控制的電子音樂發生器軟硬件上具有獨特的優點，系統的開發周期短，成本低，電路制作容易。更換歌曲時，硬件電路無需作任何修改，只需修改軟件即可實現。軟件編程時，可用51系列單片機的匯編語言或C51語言實現。同時還可根據個人的習好通過軟件改變節拍的延時時間，增加電子音樂的趣味性。
1.1.1發音原理介紹
發音原理：播放一段音樂需要的是兩個元素，一個是音調，另一個是音符。首先要了解對應的音調，音調主要由聲音的頻率決定，同時也與聲音強度有關。對一定強度的純音，音調隨頻率的升降而升降；對一定頻率的純音、低頻純音的音調隨聲強增加而下降，高頻純音的音調卻隨強度增加而上升。另外，音符的頻率有所不同。基于上面的內容，這樣就對發音的原理有了一些初步的了解。
音符的發音主要靠不同的音頻脈沖。利用單片機的內部定時器/計數器0，使其工作在模式1，定時中斷，然后控制P3.7引腳的輸出音樂。只要算出某一音頻的周期（1/頻率），然后將此周期除以2，即為半周期的時間，利用定時器計時這個半周期時間，每當計時到后就將輸出脈沖的I/O反相，然后重復計時此半周期時間再對I/O反相，就可在I/O腳上得到此頻率的脈沖。
1.1.2 音符頻率的產生
音符及定時器初始值：
例如：中音1（do）的音頻=523HZ,周期T=1/523s=1912
定時器/計數器0的定時時間為：T/2=1912/2
定時器956的計數值=定時時間/機器周期=956/1=956(時鐘頻率=12MHZ)
裝入T0計數器初值為65536-956=64580 將64580裝入T0寄存器中，啟動T0工作后，每計數956次時將產生溢出中斷，進入中斷服務時，每次對P3.0引腳的輸出值進行取反，就可得到中音DO（523HZ）的音符音頻。將51單片機內部定時器工作在計數器模式1下，改變計數初值TH0,TL0以產生不同的頻率。
若該設計使用數字電路完成,所設計的電路相當復雜,大概需要十幾片數字集成塊,其功能也主要依賴于數字電路的各功能模塊的組合來實現,焊接的過程比較復雜,成本也非常高。若用單片機來設計制作完成,由于其功能的實現主要通過軟件編程來完成,那么就降低了硬件電路的復雜性,而且其成本也有所降低,所以在該設計中采用單片機利用AT89C51,它是低功耗、高性能的CMOS型8位單片機。片內帶有4KB的Flash存儲器,且允許在系統內改寫或用編程器編程。另外, AT89C51的指令系統和引腳與8051完全兼容,片內有128B 的RAM、32條I/O口線、2個16位定時計數器、5個中斷源、一個全雙工串行口等.
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