基于51单片机和FFT算法的音频频谱分析

#include<STC12C5A60S2.H>typedef unsigned char uint8;typedef unsigned int  uint16;#define  channel  0x01     //设置AD通道为 P1.0#define ADC_POWER   (1<<7)#define ADC_SPEEDHH (0x03<<5)#define ADC_START   (1<<3)#define PADCH       (1<<5)#define ADC_FLAG    (1<<4)#define P_3 P3 //32列扫描控制sbit sw=P1^2;//74HC154组切换控制位//放大128倍后的sin整数表（128） code char SIN_TAB[128]={0,6,12,18,24,30,36,42,48,54,59,65,70,75,80,85,89,94,98,102,                        105,108,112,114,117,119,121,123,124,125,126,126,126,126,126,      125,124,123,121,119,117,114,112,108,105,102,98,94,89,85,80,75,      70,65,59,54,48,42,36,30,24,18,12,6,0,-6,-12,-18,-24,-30,-36,-42,      -48,-54,-59,-65,-70,-75,-80,-85,-89,-94,-98,-102,-105,-108,-112,      -114,-117,-119,-121,-123,-124,-125,-126,-126,-126,-126,-126,-125,      -124,-123,-121,-119,-117,-114,-112,-108,-105,-102,-98,-94,-89,-85,      -80,-75,-70,-65,-59,-54,-48,-42,-36,-30,-24,-18,-12,-6};//放大128倍后的cos整数表（128）code char COS_TAB[128]={127,126,126,125,124,123,121,119,117,114,112,108,105,102,98,94,                        89,85,80,75,70,65,59,54,48,42,36,30,24,18,12,6,0,-6,-12,-18,-24,      -30,-36,-42,-48,-54,-59,-65,-70,-75,-80,-85,-89,-94,-98,-102,      -105,-108,-112,-114,-117,-119,-121,-123,-124,-125,-126,-126,-126,      -126,-126,-125,-124,-123,-121,-119,-117,-114,-112,-108,-105,-102,      -98,-94,-89,-85,-80,-75,-70,-65,-59,-54,-48,-42,-36,-30,-24,-18,      -12,-6,0,6,12,18,24,30,36,42,48,54,59,65,70,75,80,85,89,94,98,102,      105,108,112,114,117,119,121,123,124,125,126,126};//采样存储序列表code char LIST_TAB[128] = {0,64,32,96,16,80,48,112,8,72,40,104,24,88,56,120,4,68,36,100,20,84,52,116,                           12,76,44,108,28,92,60,124,2,66,34,98,18,82,50,114,10,74,42,106,26,90,58,         122,6,70,38,102,22,86,54,118,14,78,46,110,30,94,62,126,1,65,33,97,17,81,49,         113,9,73,41,105,25,89,57,121,5,69,37,101,21,85,53,117,13,77,45,109,29,93,61,         125,3,67,35,99,19,83,51,115,11,75,43,107,27,91,59,123,7,71,39,103,23,87,55,         119,15,79,47,111,31,95,63,127};uint8 LED[32]={0x80,0x00,0xC0,0x00,0xE0,0x00,0xF0,0x00,               0xF8,0x00,0xFC,0x00,0xFE,0x00,0xFF,0x00,               0xff,0x80,0xff,0xC0,0xff,0xE0,0xff,0xF0,      0xff,0xF8,0xff,0xFC,0xff,0xFE,0xff,0xFF,};uint8 COUNT=15,COUNT1=0,ADC_Count=0,LINE=15,G=0,T;uint8 i,j,k,b,p,anum,led=0;                int Temp_Real,Temp_Imag,temp;                // 中间临时变量 uint16 TEMP1,max=0; int xdata Fft_Real[128];int xdata Fft_Image[128];               // fft的虚部uint8 xdata LED_TAB2[16];    //记录 漂浮物 是否需要 停顿一下uint8 xdata LED_TAB[16];    //记录红色柱状uint8 xdata LED_TAB1[16];    //记录 漂浮点/////////////shop60610364.taobao.com/////////void FFT()//基2fft{                    for( i=1; i<=7; i++)                            /* for(1) */    {        b=1;        b <<=(i-1);                                 //碟式运算，用于计算隔多少行计算例如 第一极 1和2行计算        for( j=0; j<=b-1; j++)                      /* for (2) */        {            p=1;            p <<= (7-i);                       p = p*j;            for( k=j; k<128; k=k+2*b)               /* for (3)  */            {                Temp_Real=Fft_Real[k];    Temp_Imag=Fft_Image[k];    temp=Fft_Real[k+b];                Fft_Real[k]=Fft_Real[k]+((Fft_Real[k+b]*COS_TAB[p])>>7)+((Fft_Image[k+b]*SIN_TAB[p])>>7);                Fft_Image[k]=Fft_Image[k]-((Fft_Real[k+b]*SIN_TAB[p])>>7)+((Fft_Image[k+b]*COS_TAB[p])>>7);                Fft_Real[k+b]=Temp_Real-((Fft_Real[k+b]*COS_TAB[p])>>7)-((Fft_Image[k+b]*SIN_TAB[p])>>7);                Fft_Image[k+b]=Temp_Imag+((temp*SIN_TAB[p])>>7)-((Fft_Image[k+b]*COS_TAB[p])>>7);          // 移位.防止溢出. 结果已经是本值的 1/64                              Fft_Real[k] >>= 1;                            Fft_Image[k] >>= 1;                Fft_Real[k+b] >>= 1;                                Fft_Image[k+b] >>= 1;                                                                                          }            }    } for(j=0;j<16;j++)//16分频            {                      TEMP1=((((Fft_Real[j+1]* Fft_Real[j+1]))+((Fft_Image[j+1]*Fft_Image[j+1])))>>1);//求各频段幅值  if(TEMP1<1)TEMP1=0;  LED_TAB[j]=TEMP1;   if(LED_TAB[j]>max)max=LED_TAB[j]; } if(max>16)//分级量化 {   max/=16;   for(j=0;j<16;j++)LED_TAB[j]/=max; }      }void delay2us(void)   //2us延时{    unsigned char a,b;    for(b=1;b>0;b--)        for(a=3;a>0;a--);} void Init(){  //-----------------------------------------------------------------------------------     P1ASF = 0x02;                 //0000,0010, 将 P1.1 置成模拟口     AUXR1 &=0xFB;                 //1111,1011, 令 ADRJ=0  EADC=1;        //AD中断打开  ADC_CONTR = ADC_POWER | ADC_SPEEDHH | ADC_START | channel;//1110 1001   1打开 A/D （ADC_POWER）转换电源；11速度为90周期一次；                                                      //0中断标志清零；1启动adc(ADC_START);001AD通道打开（这里为P1.1）;//-----------------------------------------------------------------------------------   P2M0=1;     TMOD=0X12;         TH0=0xb0;                                        TL0=0xb0;  TH1=0xfe;                TL1=0Xd4;  ET0=1;            //定时器0 打开  TR0=0;            //关闭定时器  ET1=1;  TR1=1;  PT1=0;  PT0=1;     IPH=PADCH;  IP=PADC;        //中断优先级  EA=1;         //总中断打开}//----------------------------------------------------------------------------------------  void ADC_Finish() interrupt 5 {    ADC_CONTR &= !ADC_FLAG;     Fft_Real[LIST_TAB[ADC_Count]]=(int)((ADC_RES)<<1)+(ADC_RESL>>1)*2;//按LIST_TAB表里的顺序，进行存储采样值   if(ADC_Count<=127)ADC_Count++;   else {EADC=0;TR0=0;}                 }//--------------------------------------------------------------------------------------- void LED_Display() interrupt 3      //中断一次显示一列 {     TH1=0xfe;             TL1=0Xd4;          G++;             if(G==33)G=1; switch(G)             //往点阵屏填充一列的数据   {  case 1:sw=1;anum=LED_TAB[0];P_3=0x00;break;  case 2:anum=LED_TAB[0];P_3=0x01;break;  case 3:anum=LED_TAB[1];P_3=0x02;break;  case 4:anum=LED_TAB[1];P_3=0x03;break;  case 5:anum=LED_TAB[2];P_3=0x04;break;  case 6:anum=LED_TAB[2];P_3=0x05;break;  case 7:anum=LED_TAB[3];P_3=0x06;break;  case 8:anum=LED_TAB[3];P_3=0x07;break;  case 9:anum=LED_TAB[4];P_3=0x08;break;  case 10:anum=LED_TAB[4];P_3=0x09;break;  case 11:anum=LED_TAB[5];P_3=0x0a;break;  case 12:anum=LED_TAB[5];P_3=0x0b;break;  case 13:anum=LED_TAB[6];P_3=0x0c;break;  case 14:anum=LED_TAB[6];P_3=0x0d;break;  case 15:anum=LED_TAB[7];P_3=0x0e;break;  case 16:anum=LED_TAB[7];P_3=0x0f;break;  case 17:sw=0;anum=LED_TAB[8];P_3=0x00;break;  case 18:anum=LED_TAB[8];P_3=0x10;break;  case 19:anum=LED_TAB[9];P_3=0x20;break;  case 20:anum=LED_TAB[9];P_3=0x30;break;  case 21:anum=LED_TAB[10];P_3=0x40;break;  case 22:anum=LED_TAB[10];P_3=0x50;break;  case 23:anum=LED_TAB[11];P_3=0x60;break;  case 24:anum=LED_TAB[11];P_3=0x70;break;  case 25:anum=LED_TAB[12];P_3=0x80;break;  case 26:anum=LED_TAB[12];P_3=0x90;break;  case 27:anum=LED_TAB[13];P_3=0xa0;break;  case 28:anum=LED_TAB[13];P_3=0xb0;break;  case 29:anum=LED_TAB[14];P_3=0xc0;break;  case 30:anum=LED_TAB[14];P_3=0xd0;break;  case 31:anum=LED_TAB[15];P_3=0xe0;break;  case 32:anum=LED_TAB[15];P_3=0xf0;break;       }    for(led=0;led<=anum;led++)     //递增      { P0=LED[2*led+1];     P2=LED[2*led];     delay2us();       }           //递减    for(;led>=0;led--)      { P0=LED[2*led+1];     P2=LED[2*led];     delay2us();   } }//------------------------------------------------------------------------------------------------------------void Ad_Control() interrupt 1      //控制采样率{ ADC_CONTR = ADC_POWER | ADC_SPEEDHH| ADC_START | channel;  //开始AD采集}          //=============================================================================================================== void main() {    uint8 i;  Init(); while(1) {    ADC_Count=0;  TR0=1;  EADC=1; //开启定时器中断0，开启ADC  while(ADC_Count<128);        for(i=0;i<128;i++)        {         Fft_Image[i]=0;        }  FFT();//FFT运算并转换为各频段幅值           } }