這個問題有點復雜。一個個地說吧。
首先是音樂的知識:
第一:音樂與頻率的關系——標準A = 440 Hz,高8度音的頻率為原來音頻率的2倍。我們不是搞音樂的,這個就不多說。
第二:音階與頻率的具體關系:
音階 Octave0 Octave1 Octave2 Octave3
Do C 262 523 1047 2093
Db 277 554 1109 2217
Re D 294 587 1175 2349
Eb 311 622 1245 2489
Mi E 330 659 1329 2637
Fa F 349 698 1397 2794
Gb 370 740 1480 2960
Sol G 392 784 1568 3136
Ab 415 831 1661 3322
La A 440 880 1760 3520
Bb 466 923 1865 3729
Si B 494 988 1976 3951
有了這些知識,就可以用單片機控制頻率,讓蜂鳴器發出音樂了。
怎么編程呢?
給你一個程序:
/*
本實例利用無源蜂鳴器發出音樂聲音。
還用到了定時計數器0
*/
#include <reg51.h>
#define uint unsigned int
#define uchar unsigned char
sbit voice=P1^5;//蜂鳴器I/O口
uchar code sound[]={0xff,
/*
軟件使用規則:
下面已經定義好了簡譜對應的頻率數據
節拍數據為:
四分之一拍:0x10
四分之二拍:0x20
四分之三拍:0x30
一拍:0x40
一又四分之一拍:0x60
兩拍:0x80
三拍:0xc0
音樂數據是這樣的:兩個十六進制數據,表達一個音符,它包含信息有:第一個數據為音階,第二數據為節拍,一定是成對放置。
*/
//此后為音樂樂譜,全部為3拍
0x60,0xc0,//低音階1,2,3,4,5,6,7
0x55,0xc0,
0x4c,0xc0,
0x48,0xc0,
0x40,0xc0,
0x39,0xc0,
0x33,0xc0,
0x30,0xc0,//中音階1,2,3,4,5,6,7
0x2b,0xc0,
0x26,0xc0,
0x24,0xc0,
0x20,0xc0,
0x1c,0xc0,
0x19,0xc0,
0x18,0xc0,//高音階1,2,3,4,5,6,7
0x15,0xc0,
0x13,0xc0,
0x12,0xc0,
0x10,0xc0,
0x0e,0xc0,
0x0d,0xc0,
0x26,0x20,0x2b,0x20,0x26,0x80,0xff,0x20,0x2b,0x20,0x26,0x20,0x26,0x10,//兩只蝴蝶
0x2b,0x10,0x30,0x80,0xff,0x40,0x39,0x20,0x30,0x20,0x2b,0x40,0x2b,0x20,
0x26,0x20,0x2b,0x20,0x30,0x20,0x39,0x20,0x39,0x10,0x30,0x10,0x40,0x80,
0x40,0x80,0x26,0x20,0x2b,0x20,0x26,0x80,0xff,0x20,0x2b,0x20,0x26,0x20,
0x26,0x10,0x2b,0x10,0x30,0x80,0xff,0x40,0x39,0x20,0x30,0x20,0x2b,0x40,
0x2b,0x20,0x26,0x20,0x2b,0x20,0x30,0x20,0x39,0x20,0x30,0x20,0x2b,0xc0,
0x26,0x20,0x2b,0x20,0x26,0x80,0xff,0x20,0x2b,0x20,0x26,0x20,0x26,0x10,
0x2b,0x10,0x30,0xc0,0x39,0x20,0x30,0x20,0x2b,0x40,0x2b,0x20,0x26,0x20,
0x2b,0x20,0x30,0x20,0x39,0x20,0x39,0x10,0x30,0x10,0x40,0xc0,0x26,0x20,
0x20,0x20,0x20,0x80,0xff,0x20,0x20,0x20,0x1c,0x20,0x20,0x20,0x26,0xc0,
0x2b,0x20,0x2b,0x20,0x2b,0x60,0x2b,0x20,0x26,0x20,0x2b,0x20,0x30,0x20,
0x39,0x20,0x39,0x20,0x30,0x20,0x30,0x20,0x30,0xc0,0xff,0x40,0xff,0x40,
0xff,0x20,0x20,0x20,0x20,0x20,0x1c,0x20,0x18,0x20,0x19,0x20,0x19,0x20,
0x1c,0x20,0x26,0x20,0x2b,0x20,0x2b,0x20,0x26,0x20,0x26,0x80,0xff,0x20,
0x26,0x20,0x26,0x20,0x20,0x20,0x1c,0x40,0x1c,0x40,0xff,0x20,0x39,0x20,
0x26,0x20,0x2b,0x20,0x2b,0xc0,0x26,0x20,0x20,0x20,0x20,0x20,0x26,0x20,
0x20,0x40,0xff,0x20,0x18,0x40,0x19,0x20,0x1c,0x20,0x1c,0x10,0x19,0x10,
0x26,0x40,0xff,0x20,0x1c,0x20,0x1c,0x20,0x19,0x20,0x1c,0x20,0x20,0x20,
0x26,0x20,0x2b,0x20,0xff,0x20,0x26,0x20,0x2b,0x20,0x26,0x20,0x20,0x80,
0xff,0x20,0x20,0x20,0x20,0x20,0x1c,0x20,0x18,0x20,0x19,0x20,0x19,0x20,
0x1c,0x20,0x26,0x20,0x2b,0x20,0x2b,0x20,0x26,0x20,0x26,0x80,0xff,0x20,
0x26,0x20,0x26,0x20,0x20,0x20,0x1c,0x40,0x1c,0x40,0xff,0x20,0x39,0x20,
0x26,0x20,0x2b,0x20,0x2b,0xc0,0x26,0x20,0x20,0x20,0x20,0x20,0x26,0x20,
0x20,0x40,0xff,0x20,0x18,0x40,0x19,0x20,0x1c,0x20,0x1c,0x10,0x19,0x10,
0x26,0x40,0xff,0x20,0x1c,0x20,0x1c,0x20,0x19,0x20,0x1c,0x20,0x20,0x20,
0x26,0x20,0x2b,0x20,0xff,0x20,0x40,0x40,0x39,0x20,0x30,0xc0,0xff,0xc0,
0xff,0xc0,//休止符
,0x00};
uchar zdjs=0, jp;//jp為節拍變量,
void del(yj);//yj為音階變量,延時為了樂音高低
void main(void)
{
uint dpjs=0;//讀數據的指針
uchar yj;
TMOD=0x01;//定時器0,工作方式1:16位定時器(0~65535),定時器模式,由運行控制位TR0開啟
IE=0x82;//中斷允許寄存器設置,等于以下分別的設置:EA=1總中斷允許,ET0=1定時器中斷0允許;
TH0=0xd8;//給定時器賦初值,即定時時間的長短:12MHz下10ms
TL0=0xf0;
TR0=1;//啟動定時器0
while(1)
{
zdjs=0;//節拍長短的計數器計數變量
dpjs++; yj=sound[dpjs];
dpjs++; jp=sound[dpjs];
while(zdjs!=jp)
{
if(yj!=0xff)
{
if(yj!=0)
{
voice=!voice;
del(yj);
}
else
{
dpjs=0;
break;
}
}
else
{
voice=1;
del(jp);
}
}
}
}
void time0() interrupt 1
{
TH0=0xd8;//定時10ms,12M
TL0=0xf0;
zdjs++;
}
void del(yj)
{
uchar yj2=2;
while(yj!=0)
{
while(yj2!=0)
{
yj2--;
}
yj2=2;
yj--;
}
}
好了,電子音樂已經可以通過51單片機進行演奏了。
還可以有其它的演奏辦法:
第一:上述程序不是唯一的,只要能控制好蜂鳴器發聲音的頻率,就可以發出音樂。
第二:還可以通過電子電路的設計,通過雙穩態電路(模擬電路)或其它芯片,可以得到發音樂的結果。小孩玩的電子琴,就是這樣來的。網上很多資料,這里不多說了。
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