基于51单片机的电子琴

朱雀 2024-04-18 22:51 69阅读 0赞

同学的毕业设计

好吧，我又牺牲了玩游戏的时间！

整体框图：

![20130819174627687][]

![20130819174725984][]

程序流程图：

![20130819174845000][]

源码也比较简单：

#include <reg52.h>
    #include <intrins.h>
    //本程序是电子琴的程序，能够实现单独演奏和放一首歌曲的功能。其中，按键1~15是用于单独演奏的，按键16是用于播放歌曲的
    //播放歌曲的时候需要按复位键才能够停止。
    //共阳极数码管段码表,最后一字节为黑屏
    unsigned char code DSY_CODE[]={0x28,0xee,0x34,0xa4,0xe2,0xa1,0x21,0xec,0x20,0xa0,0x60,0x23,0x39,0x26,0x31,0x71,0xbf};
    //各音符对应的延时表
    unsigned int code tone_delay_table[]={64021,64103,64260,64400,64524,64580,64684,64777,64820,64898,64968,65030,65058,65110,65157,65178};
    //蜂鸣器的位定义
    sbit beep=P3^0;
    #define SOUND_SPACE 	4/5 		//定义普通音符演奏的长度分率,//每4分音符间隔
    //同一首歌 的谱子
    unsigned char code Music[]={  0x0F,0x01, 0x15,0x02, 0x16,0x02, 0x17,0x66, 0x18,0x03,
    	                   0x17,0x02, 0x15,0x02, 0x16,0x01, 0x15,0x02, 0x10,0x02,
    	                   0x15,0x00, 0x0F,0x01, 0x15,0x02, 0x16,0x02, 0x17,0x02,
    	                   0x17,0x03, 0x18,0x03, 0x19,0x02, 0x15,0x02, 0x18,0x66,
    	                   0x17,0x03, 0x19,0x02, 0x16,0x03, 0x17,0x03, 0x16,0x00,
    	                   0x17,0x01, 0x19,0x02, 0x1B,0x02, 0x1B,0x70, 0x1A,0x03,
    	                   0x1A,0x01, 0x19,0x02, 0x19,0x03, 0x1A,0x03, 0x1B,0x02,
    	                   0x1A,0x0D, 0x19,0x03, 0x17,0x00, 0x18,0x66, 0x18,0x03,
    	                   0x19,0x02, 0x1A,0x02, 0x19,0x0C, 0x18,0x0D, 0x17,0x03,
    	                   0x16,0x01, 0x11,0x02, 0x11,0x03, 0x10,0x03, 0x0F,0x0C,
    	                   0x10,0x02, 0x15,0x00, 0x1F,0x01, 0x1A,0x01, 0x18,0x66,
    	                   0x19,0x03, 0x1A,0x01, 0x1B,0x02, 0x1B,0x03, 0x1B,0x03,
    	                   0x1B,0x0C, 0x1A,0x0D, 0x19,0x03, 0x17,0x00, 0x1F,0x01,
    	                   0x1A,0x01, 0x18,0x66, 0x19,0x03, 0x1A,0x01, 0x10,0x02,
    	                   0x10,0x03, 0x10,0x03, 0x1A,0x0C, 0x18,0x0D, 0x17,0x03,
    	                   0x16,0x00, 0x0F,0x01, 0x15,0x02, 0x16,0x02, 0x17,0x70,
    	                   0x18,0x03, 0x17,0x02, 0x15,0x03, 0x15,0x03, 0x16,0x66,
    	                   0x16,0x03, 0x16,0x02, 0x16,0x03, 0x15,0x03, 0x10,0x02,
    	                   0x10,0x01, 0x11,0x01, 0x11,0x66, 0x10,0x03, 0x0F,0x0C,
    	                   0x1A,0x02, 0x19,0x02, 0x16,0x03, 0x16,0x03, 0x18,0x66,
    	                   0x18,0x03, 0x18,0x02, 0x17,0x03, 0x16,0x03, 0x19,0x00,
    	                   0x00,0x00 };
    unsigned int  code FreTab[12]  = { 269,275,304,311,334,346,368,396,413,449,467,499 }; //原始频率表
    unsigned char code SignTab[7]  = { 0,2,4,5,7,9,11 }; 	//1~7在频率表中的位置
    unsigned char code LengthTab[7]= { 1,2,4,8,16,32,64 };
    unsigned char Sound_Temp_TH0,Sound_Temp_TL0;	//音符定时器初值暂存 
    unsigned char Sound_Temp_TH1,Sound_Temp_TL1;	//音长定时器初值暂存
    void delay_1ms(unsigned int ms) { unsigned char i; while(ms--) for(i=0;i<120;i++);}   //延时1ms
    //播放音乐的子函数
    void Play(unsigned char *Sound,unsigned char Signature,unsigned Octachord,unsigned int Speed)
    {
    unsigned int NewFreTab[12];		//新的频率表
    unsigned char i,j;		   //定义一些中间变量
    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++) 				// 根据调号及升降八度来生成新的频率表 
    {
    	j = i + Signature;
    	if(j > 11)
    	{
    		j = j-12;
    		NewFreTab[i] = FreTab[j]*2;//计算新的频率
    		}
    		else
    			NewFreTab[i] = FreTab[j];
    
    		if(Octachord == 1)
    			NewFreTab[i]>>=2;
    		else if(Octachord == 3)
    			NewFreTab[i]<<=2;
    	}									
    	
    	SoundLength = 0;
    while(Sound[SoundLength] != 0x00)	//计算歌曲长度
    {
    SoundLength+=2;
    	}
    
    	Point = 0;
    	Tone   = Sound[Point];	
    	Length = Sound[Point+1]; 			// 读出第一个音符和它时时值
    	
    	LDiv0 = 12000/Speed;				// 算出1分音符的长度(几个10ms) 	
    	LDiv4 = LDiv0/4; 					// 算出4分音符的长度 
    	LDiv4 = LDiv4-LDiv4*SOUND_SPACE; 	// 普通音最长间隔标准 
    	TR0	  = 0;
    	TR1   = 1;
    while(Point < SoundLength)
    {
    	SL=Tone%10; 								//计算出音符 
    	SM=Tone/10%10; 								//计算出高低音 
    	SH=Tone/100; 								//计算出是否升半 
    	CurrentFre = NewFreTab[SignTab[SL-1]+SH]; 	//查出对应音符的频率 	
    	if(SL!=0)
    	{
    		if (SM==1) CurrentFre >>= 2; 		//低音 
    		if (SM==3) CurrentFre <<= 2; 		//高音
    		Temp_T = 65536-(500000/CurrentFre)*10;//计算计数器初值
    		Sound_Temp_TH0 = Temp_T/256; 
    		Sound_Temp_TL0 = Temp_T%256; 
    		TH0 = Sound_Temp_TH0;  
    		TL0 = Sound_Temp_TL0; 
    		}
    		SLen=LengthTab[Length%10]; 	//算出是几分音符
    		XG=Length/10%10; 			//算出音符类型(0普通1连音2顿音) 
    		FD=Length/100;
    		LDiv=LDiv0/SLen; 			//算出连音音符演奏的长度(多少个10ms)
    		if (FD==1) 
    			LDiv=LDiv+LDiv/2;
    		if(XG!=1)	
    			if(XG==0) 				//算出普通音符的演奏长度 
    				if (SLen<=4)	
    					LDiv1=LDiv-LDiv4;
    				else
    					LDiv1=LDiv*SOUND_SPACE;
    			else
    				LDiv1=LDiv/2; 		//算出顿音的演奏长度 
    		else
    			LDiv1=LDiv;
    		if(SL==0) LDiv1=0;
    			LDiv2=LDiv-LDiv1; 		//算出不发音的长度 
    	  	if (SL!=0)
    		{
    			TR0=1;
    			for(i=LDiv1;i>0;i--) 	//发规定长度的音 
    			{
    				while(TF1==0);
    				TH1 = Sound_Temp_TH1;
    				TL1 = Sound_Temp_TL1;
    				TF1=0;
    			}
    		}
    		if(LDiv2!=0)
    		{
    			TR0=0; beep=1;
    			for(i=LDiv2;i>0;i--) 	//音符间的间隔
    			{
    				while(TF1==0);
    				TH1 = Sound_Temp_TH1;
    				TL1 = Sound_Temp_TL1;
    				TF1=0;
    			}
    		}
    		Point+=2; 
    		Tone=Sound[Point];
    		Length=Sound[Point+1];
    	}
    	beep = 0;
    	TR0=0;//关闭定时器
    }
    
    //键盘矩阵扫描
    //返回按下的键的值
    unsigned char keys_scan(void)
    {
    	unsigned char Tmp,k=16;
    	P2=0x0F; delay_1ms(2);
    	Tmp=P2 ^ 0x0F;
    	switch(Tmp)//确定扫描的是哪一行
    	{
    		case 1: k=0;break;
    		case 2: k=1;break;
    		case 4: k=2;break;
    		case 8: k=3;break;
    		default: return 16; //无键按下，返回
    	}
    	P2=0xF0; delay_1ms(2);
    	Tmp=(P2>>4)^0x0F;
    	switch(Tmp)//确定扫描的是那一列
    	{
    		case 1: k+=0; break;
    		case 2: k+=4; break;
    		case 4: k+=8; break;
    		case 8: k+=12;break;
    		default: return 16; //无键按下，返回
    	}
    	return k;
    }
    
    
    void main()		   //主程序
    {
    	unsigned char key_NO=0;
    	P1=0xFF; //数码管显示关闭
    	//设置定时器工作方式1，以及相关开启寄存器
    	TMOD  |= 0x11;
    	ET0    = 1;
    	ET1	   = 0;
    	TR0	   = 0;
    	TR1    = 0;
    	EA     = 1;
    	//设置定时器初值
    	TH0=tone_delay_table[key_NO]/256;
    	TL0=tone_delay_table[key_NO]%256;
    	TH1 = (65535-5000)/256;// 计算TL1应装入的初值
    	TL1 = (65535-5000)%256;
    	while(1)
    	{
    		P2=0xF0;
    		if(P2!=0xF0)//当有按键按下时，需要显示数码管及设置定时器的开启
    		{ 
    			key_NO=keys_scan();//调用键盘扫描 
    			P1=DSY_CODE[key_NO];//在数码管上显示按下的键 
    			if(key_NO<15)//按下那个键，发出对应的音调
    			{
    				Sound_Temp_TH0=tone_delay_table[key_NO]/256;
    				Sound_Temp_TL0=tone_delay_table[key_NO]%256;
    			}
    			else if(key_NO==15)//按下最后一个键时，要播放音乐
    			{
    				Play(Music, 0, 3, 300);	
    				//TR1 = 0;//音长中断
    			}
    			TR0=1;//开启定时器0，音符中断
    		}
    		else//当没有键按下时，数码管不显示，也无声音发出；如果是播放音乐，则一直显示 
    		{
    				TR0=0;//关闭定时器
    				P1=0xFF;//数码管显示关闭		
    		}
    		delay_1ms(2);//稍做延时，可以避免误判断
    	}
    }
    //音符发生的中断
    void play_tone() interrupt 1
    {
    	TH0=Sound_Temp_TH0;
    	TL0=Sound_Temp_TL0;
    	
    	beep=~beep;
    }

[20130819174627687]: https://img-blog.csdn.net/20130819174627687
[20130819174725984]: https://img-blog.csdn.net/20130819174725984
[20130819174845000]: https://img-blog.csdn.net/20130819174845000