Question

单片机播放音乐的原理

Answer 1

单片机发音原理：利用定时器或PWM功能，输出PWM，经一级有源滤波后放大驱动扬声器。
单片机演奏音乐基本是单音频率，它不包含相应幅度的谐波频率，
也就是说不能象电子琴那样能奏出多种音色的声音，但一定要弄清楚两个概念即可，也就是“音调”和“节拍” 。音调 表示一个音符唱多高的频率。节拍 表示一个音符唱多长的时间
1.要生产音频脉冲,只要算出某一音频的周期(1/频率),然后将此周期除以2,即为半周期的时间.利用定时器计时这个半周期时间,每当计时到后就将输出脉冲的I/O反相,然后重复计时此半周期时间再对I/O反相,就可在I/O脚上得到此频率的脉冲。

2. 利用8051的内部定时器使用其工作在计数器模式MODE1下,改变计数值THO及TLO以产生不同频率的方法。

Answer 2

这是一个单片机播放音乐的程序，给你参考一下。

#include "reg52.h"
unsigned char Count;
sbit _Speak =P2^3 ; //讯响器控制脚　

unsigned char code SONG[] ={ //祝你平安
0x26,0x20,0x20,0x20,0x20,0x20,0x26,0x10,0x20,0x10,0x20,0x80,0x26,0x20,0x30,0x20,
0x30,0x20,0x39,0x10,0x30,0x10,0x30,0x80,0x26,0x20,0x20,0x20,0x20,0x20,0x1c,0x20,
0x20,0x80,0x2b,0x20,0x26,0x20,0x20,0x20,0x2b,0x10,0x26,0x10,0x2b,0x80,0x26,0x20,
0x30,0x20,0x30,0x20,0x39,0x10,0x26,0x10,0x26,0x60,0x40,0x10,0x39,0x10,0x26,0x20,
0x30,0x20,0x30,0x20,0x39,0x10,0x26,0x10,0x26,0x80,0x26,0x20,0x2b,0x10,0x2b,0x10,
0x2b,0x20,0x30,0x10,0x39,0x10,0x26,0x10,0x2b,0x10,0x2b,0x20,0x2b,0x40,0x40,0x20,
0x20,0x10,0x20,0x10,0x2b,0x10,0x26,0x30,0x30,0x80,0x18,0x20,0x18,0x20,0x26,0x20,
0x20,0x20,0x20,0x40,0x26,0x20,0x2b,0x20,0x30,0x20,0x30,0x20,0x1c,0x20,0x20,0x20,
0x20,0x80,0x1c,0x20,0x1c,0x20,0x1c,0x20,0x30,0x20,0x30,0x60,0x39,0x10,0x30,0x10,
0x20,0x20,0x2b,0x10,0x26,0x10,0x2b,0x10,0x26,0x10,0x26,0x10,0x2b,0x10,0x2b,0x80,
0x18,0x20,0x18,0x20,0x26,0x20,0x20,0x20,0x20,0x60,0x26,0x10,0x2b,0x20,0x30,0x20,
0x30,0x20,0x1c,0x20,0x20,0x20,0x20,0x80,0x26,0x20,0x30,0x10,0x30,0x10,0x30,0x20,
0x39,0x20,0x26,0x10,0x2b,0x10,0x2b,0x20,0x2b,0x40,0x40,0x10,0x40,0x10,0x20,0x10,
0x20,0x10,0x2b,0x10,0x26,0x30,0x30,0x80,0x00,
//路边的野华不要采
0x30,0x1C,0x10,0x20,0x40,0x1C,0x10,0x18,0x10,0x20,0x10,0x1C,0x10,0x18,0x40,0x1C,
0x20,0x20,0x20,0x1C,0x20,0x18,0x20,0x20,0x80,0xFF,0x20,0x30,0x1C,0x10,0x18,0x20,
0x15,0x20,0x1C,0x20,0x20,0x20,0x26,0x40,0x20,0x20,0x2B,0x20,0x26,0x20,0x20,0x20,
0x30,0x80,0xFF,0x20,0x20,0x1C,0x10,0x18,0x10,0x20,0x20,0x26,0x20,0x2B,0x20,0x30,
0x20,0x2B,0x40,0x20,0x20,0x1C,0x10,0x18,0x10,0x20,0x20,0x26,0x20,0x2B,0x20,0x30,
0x20,0x2B,0x40,0x20,0x30,0x1C,0x10,0x18,0x20,0x15,0x20,0x1C,0x20,0x20,0x20,0x26,
0x40,0x20,0x20,0x2B,0x20,0x26,0x20,0x20,0x20,0x30,0x80,0x20,0x30,0x1C,0x10,0x20,
0x10,0x1C,0x10,0x20,0x20,0x26,0x20,0x2B,0x20,0x30,0x20,0x2B,0x40,0x20,0x15,0x1F,
0x05,0x20,0x10,0x1C,0x10,0x20,0x20,0x26,0x20,0x2B,0x20,0x30,0x20,0x2B,0x40,0x20,
0x30,0x1C,0x10,0x18,0x20,0x15,0x20,0x1C,0x20,0x20,0x20,0x26,0x40,0x20,0x20,0x2B,
0x20,0x26,0x20,0x20,0x20,0x30,0x30,0x20,0x30,0x1C,0x10,0x18,0x40,0x1C,0x20,0x20,
0x20,0x26,0x40,0x13,0x60,0x18,0x20,0x15,0x40,0x13,0x40,0x18,0x80,0x00,

};

void Time0_Init()
{
TMOD = 0x01;
IE = 0x82;
TH0 = 0xD8;
TL0 = 0xEF; //12MZ晶振，10ms
}

void Time0_Int() interrupt 1
{
TH0 = 0xD8;
TL0 = 0xEF;
Count++; //长度加1
}

/*-------------------------------------------------
功能:1MS延时子程序
-------------------------------------------------*/
void Delay_xMs(unsigned int x)
{
unsigned int i,j;
for( i =0;i < x;i++ )
{
for( j =0;j<3;j++ );
}
}

/*-------------------------------------------------
功能:歌曲播放子程序i为播放哪一段曲目
-------------------------------------------------*/
void Play_Song(unsigned char i)
{
unsigned char Temp1,Temp2;
unsigned int Addr;
Count = 0; //中断计数器清0
Addr = i * 217;
while(1)
{
Temp1 = SONG[Addr++];
if ( Temp1 == 0xFF ) //休止符
{
TR0 = 0;
Delay_xMs(100);
}
else if ( Temp1 == 0x00 ) //歌曲结束符
{
return;
}
else
{
Temp2 = SONG[Addr++];
TR0 = 1;
while(1)
{
_Speak = ~_Speak;
Delay_xMs(Temp1);
if ( Temp2 == Count )
{
Count = 0;
break;
}
}
}
}
}
/*-------------------------------------------------
功能:主程序
-------------------------------------------------*/
void main()
{
Time0_Init(); //定时器0中断初始化
while(1)
{
Play_Song(0); //播放
}
}

Answer 3

很简单，不同频率（音高）输出不同时长（时值）。

Answer 4

单片机内歌曲的代码怎么来的