51单片机.之蜂鸣器振动播放歌曲

蜂鸣器发声是通过喇叭振动发声的，通电产生磁场，磁铁吸收，而振动。不断释放，吸收。

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1、蜂鸣器发声，播放不同频率的声音逐渐变尖

#include<reg52.h>sbit BUZZ = P1^6;unsigned char T0RH=0;
unsigned char T0RL=0;
void OpenBuzz(unsigned int frequ);
void StopBuzz();void main()
{unsigned int i;EA =1;TMOD = 0x01;while(1){OpenBuzz(4000);for(i=0; i<40000; i++);StopBuzz();for(i=0; i<40000; i++);OpenBuzz(1000);for(i=0; i<40000; i++);StopBuzz();for(i=0; i<40000; i++);}
}void OpenBuzz(unsigned int frequ)
{unsigned int reload;reload = 65536 - (11059200/12)/(frequ*2); T0RH = (unsigned char)(reload >>8);T0RL = (unsigned char)reload;TH0 = 0xFF;TL0 = 0xFE;ET0 = 1;TR0 = 1;
}void StopBuzz()
{ET0 = 0;TR0 = 0;
}void InterruptTimer0() interrupt 1
{TH0 = T0RH;TL0 = T0RL;BUZZ = ~BUZZ;
}

2、蜂鸣器播放歌曲


#include <reg52.h>sbit BUZZ = P1^6;  //蜂鸣器控制引脚unsigned int code NoteFrequ[] = {  //中音1-7和高音1-7对应频率列表523,  587,  659,  698,  784,  880,  988,  //中音1-71047, 1175, 1319, 1397, 1568, 1760, 1976  //高音1-7
};
unsigned int code NoteReload[] = { //中音1-7和高音1-7对应的定时器重载值65536 - (11059200/12) / (523*2),  //中音165536 - (11059200/12) / (587*2),  //265536 - (11059200/12) / (659*2),  //365536 - (11059200/12) / (698*2),  //465536 - (11059200/12) / (784*2),  //565536 - (11059200/12) / (880*2),  //665536 - (11059200/12) / (988*2),  //765536 - (11059200/12) / (1047*2), //高音165536 - (11059200/12) / (1175*2), //265536 - (11059200/12) / (1319*2), //365536 - (11059200/12) / (1397*2), //465536 - (11059200/12) / (1568*2), //565536 - (11059200/12) / (1760*2), //665536 - (11059200/12) / (1976*2), //7
};
bit enable = 1;   //蜂鸣器发声使能标志
bit tmrflag = 0;  //定时器中断完成标志
unsigned char T0RH = 0xFF;  //T0重载值的高字节
unsigned char T0RL = 0x00;  //T0重载值的低字节void PlayTwoTiger();void main()
{unsigned int i;EA = 1;       //使能全局中断TMOD = 0x01;  //配置T0工作在模式1TH0 = T0RH;TL0 = T0RL;ET0 = 1;      //使能T0中断TR0 = 1;      //启动T0while (1){PlayTwoTiger();  //播放乐曲--两支老虎for (i=0; i<40000; i++);  //停止一段时间}
}
/* 两只老虎乐曲播放函数 */
void PlayTwoTiger()
{unsigned char beat;   //当前节拍索引unsigned char note;   //当前节拍对应的音符unsigned int time = 0;      //当前节拍计时unsigned int beatTime = 0;  //当前节拍总时间unsigned int soundTime = 0; //当前节拍需发声时间//两只老虎音符表unsigned char code TwoTigerNote[] = {1,   2,   3, 1,    1,   2,   3, 1,   3, 4, 5,   3, 4, 5,5,6, 5,4, 3, 1,    5,6, 5,4, 3, 1,   1, 5, 1,   1, 5, 1,};//两只老虎节拍表，4表示一拍，1就是1/4拍，8就是2拍unsigned char code TwoTigerBeat[] = {4,   4,   4, 4,    4,   4,   4, 4,   4, 4, 8,   4, 4, 8,3,1, 3,1, 4, 4,    3,1, 3,1, 4, 4,   4, 4, 8,   4, 4, 8,};for (beat=0; beat<sizeof(TwoTigerNote); )  //用节拍索引作为循环变量{while (!tmrflag);  //每次定时器中断完成后，检测并处理节拍tmrflag = 0;if (time == 0)  //当前节拍播完则启动一个新节拍{note = TwoTigerNote[beat] - 1;T0RH = NoteReload[note] >> 8;T0RL = NoteReload[note];//计算节拍总时间，右移2位相当于除4，移位代替除法可以加快执行速度beatTime = (TwoTigerBeat[beat] * NoteFrequ[note]) >> 2;//计算发声时间，为总时间的0.75，移位原理同上soundTime = beatTime - (beatTime >> 2);enable = 1;  //指示蜂鸣器开始发声time++;}else  //当前节拍未播完则处理当前节拍{if (time >= beatTime)  //当前持续时间到达节拍总时间时归零，{                      //并递增节拍索引，以准备启动新节拍time = 0;beat++;}else  //当前持续时间未达到总时间时，{time++;   //累加时间计数if (time == soundTime)  //到达发声时间后，指示关闭蜂鸣器，{                       //插入0.25*总时间的静音间隔，enable = 0;         //用以区分连续的两个节拍}}}}
}
/* T0中断服务函数，用于控制蜂鸣器发声 */
void InterruptTimer0() interrupt 1
{TH0 = T0RH;   //重新加载重载值TL0 = T0RL;tmrflag = 1;if (enable)   //使能时反转蜂鸣器控制电平BUZZ = ~BUZZ;else          //未使能时关闭蜂鸣器BUZZ = 1;
}