实验三-操纵蜂鸣器演奏音乐之青柳念文创作一、实验目标二、实验硬件设计及电路1. BlueSkyC51单片机实验板三极管主要是做驱动用的.因为单片机的IO口驱动才能不敷让蜂鸣器发出声音，所以我们通过三极管放大驱动电流，从而可让蜂鸣器发出声音，你要是输出高电平，三极管导通，集电极电畅通过蜂鸣器让蜂鸣器发出声音，当输出低电平时，三极管截止，没有电流流过蜂鸣器，所以就不会发出声音.三、实验原理用一个口，输出方波，这个方波输入进蜂鸣器就会发生声音，通过节制方波的频率、时间，就可以发生简单的音乐.一般说来，单片机演奏音乐基本都是单音频率，因此单片机奏乐只需节制音调和节拍.（1）音调的确定音调是由频率来确定的.通过单片机的定时器定时中断，将单片机上对应蜂鸣器的I/O口往返取反，从而让蜂鸣器发出分歧频率的声音.只需将定时器给以分歧的定时值便可实现.通过延时，即可发出所需要的频率.（2）节拍的确定一拍的时长大约为400—500ms,每一个音符的时长通过节拍来计算.详细见程序代码.（1）头文件#include<reg51.h>#define uint unsigned int#define uchar unsigned char#define ulong unsigned long(2)歌曲曲谱uchar code diaodata[30]={ //音调代码0x10,0x0e,0x0c,0x10,0x0e,0x0c,0x10,0x0e,0x10,0x0c,0x10,0x15,0x13,0x10,0x13,0x15,0x15,0x13,0x15,0x13,0x10,0x0e,0x0c,0x0e,0x0e,0x10,0x0e,0x0c,0x0e,0x00};uchar code jiedata[30]={ //音长代码0x04,0x04,0x08,0x06,0x02,0x08,0x04,0x04,0x04,0x04,0x02,0x06,0x08,0x02,0x02,0x04,0x04,0x04,0x04,0x08,0x02,0x02,0x04,0x04,0x02,0x02,0x04,0x04,0x0c,0x00};(3)音阶表uchar code freq[36*2]={ //音阶码表0xf8,0x50, //466hz , 1# //1 0xf8,0xbc, //494hz , 2 //2 0xf9,0x26, //524hz , 2# //3 0xf9,0x85, //554hz , 3 //4 0xf9,0xe5, //588hz , 4 //5 0xfa,0x3d, //622hz , 4# //6 0xfa,0x92, //660hz , 5 //7 0xfa,0xdd, //698hz , 5# //8 0xfb,0x29, //740hz , 6 //9 0xfb,0x70, //784hz , 6# //10 0xfb,0xb0, //830hz , 7 //11 0xfb,0xef, //880hz , 1 //12 0xfc,0x29, //932hz , 1# //13 0xfc,0x62, //988hz , 2 //14 0xfc,0x95, //1046hz, 2# //15 0xfc,0xc7, //1108hz, 3 //16 0xfc,0xf5, //1174hz, 4 //17 0xfd,0x20, //1244hz, 4# //18 0xfd,0x4c, //1318hz, 5 //19 0xfd,0x72, //1396hz, 5# //20 0xfd,0x97, //1480hz, 6 //210xfd,0xdc, //1662hz, 7 //230xfd,0xfb, //1769hz, `1 //240xfe,0x18, //1864hz, `1# //250xfe,0x34, //1976hz, `2 //260xfe,0x4e, //2092hz, `2# //270xfe,0x67, //2218hz, `3 //280xfe,0x7d, //2350hz, `4 //290xfe,0x94, //2488hz, `4# //300xfe,0xa8, //2639hz, `5 //310xfe,0xbc, //2794hz, `5# //320xfe,0xcf, //2960hz, `6 //330xfe,0xe0, //3136hz, `6# //340xfe,0xf1, //3322hz, `7 //35};(4)音符发生程序（中断服务程序）void timer0() interrupt 1 //用于发生音符的T0中断服务程序{TH0=th0_f;TL0=tl0_f;beep=~beep; //取反beep引脚，发声}三、实验过程及问题(1)新建“Project”，选择单片机为“AT89C52”(2)新建c文件“music.c”，并添加到工程中(3)设置生成“HEX”文件，编译(4)将生成的“HEX”文件烧录到单片机，检验(5)不竭修改完善(1)实际发音颤音重处理方法为修改蜂鸣器的驱动频率.(2)实际节拍过快或者过慢调整延时四、C51程序代码（部分来历于网络）#include<reg51.h>#define uint unsigned int#define uchar unsigned char#define ulong unsigned longuchar th0_f; //中断装载T0高8位uchar tl0_f; //T0低8位uchar code freq[36*2]={ //音阶码表0xf7,0xd8, //440hz , 1 //00xf8,0x50, //466hz , 1# //10xf8,0xbc, //494hz , 2 //20xf9,0x26, //524hz , 2# //3 0xf9,0x85, //554hz , 3 //4 0xf9,0xe5, //588hz , 4 //5 0xfa,0x3d, //622hz , 4# //6 0xfa,0x92, //660hz , 5 //7 0xfa,0xdd, //698hz , 5# //8 0xfb,0x29, //740hz , 6 //9 0xfb,0x70, //784hz , 6# //10 0xfb,0xb0, //830hz , 7 //11 0xfb,0xef, //880hz , 1 //12 0xfc,0x29, //932hz , 1# //13 0xfc,0x62, //988hz , 2 //14 0xfc,0x95, //1046hz, 2# //15 0xfc,0xc7, //1108hz, 3 //16 0xfc,0xf5, //1174hz, 4 //17 0xfd,0x20, //1244hz, 4# //18 0xfd,0x4c, //1318hz, 5 //19 0xfd,0x72, //1396hz, 5# //20 0xfd,0x97, //1480hz, 6 //21 0xfd,0xbb, //1568hz, 6# //22 0xfd,0xdc, //1662hz, 7 //23 0xfd,0xfb, //1769hz, `1 //240xfe,0x18, //1864hz, `1# //250xfe,0x34, //1976hz, `2 //260xfe,0x4e, //2092hz, `2# //270xfe,0x67, //2218hz, `3 //280xfe,0x7d, //2350hz, `4 //290xfe,0x94, //2488hz, `4# //300xfe,0xa8, //2639hz, `5 //310xfe,0xbc, //2794hz, `5# //320xfe,0xcf, //2960hz, `6 //330xfe,0xe0, //3136hz, `6# //340xfe,0xf1, //3322hz, `7 //35};uchar code diaodata[30]={ //音调代码0x10,0x0e,0x0c,0x10,0x0e,0x0c,0x10,0x0e,0x10,0x0c,0x10,0x15,0x13,0x10,0x13,0x15,0x15,0x13,0x15,0x13,0x10,0x0e,0x0c,0x0e,0x0e,0x10,0x0e,0x0c,0x0e,0x00};uchar code jiedata[30]={ //音长代码0x04,0x04,0x08,0x06,0x02,0x08,0x04,0x04,0x04,0x04,0x02,0x06,0x08,0x02,0x02,0x04,0x04,0x04,0x04,0x08,0x02,0x02,0x04,0x04,0x02,0x02,0x04,0x04,0x0c,0x00};void timer0() interrupt 1 //用于发生音符的T0中断服务程序{TH0=th0_f;TL0=tl0_f;beep=~beep; //取反beep引脚，发声}void main(void){uchari,j,k=0;uint n;TMOD=0X01; //T0方式1TR0=0; //关闭T0（不发声）ET0=1; //允许T0中断EA=1; //允许总中断while(1){TR0=1; //开T0for(i=0;diaodata[i]!=0;i++){th0_f=freq[diaodata[i]*2];tl0_f=freq[diaodata[i]*2+1];for(j=0;j<20000;n++);//(jiedata*20000)TR0=0;for(n=0;n<256;n++); //音符之间的短暂延时TR0=1;}TR0=0;}}。
