音乐频谱.rar_fft频谱_music频谱_stc15_单片机 滤波_音乐频谱fft

#include<stc12c5a60s2.h> #include<math.h> #define uchar unsigned char #define uint unsigned int uint xdata sample[32]={0}; float xdata real[32]={0}; float xdata imag[32]={0}; float xdata cosp[]={1,0.981,0.924,0.831,0.707,0.556,0.383,0.195, 0,-0.195,-0.383,-0.556,-0.707,-0.831,-0.924,-0.981}; float xdata sinp[]={0,0.195,0.383,0.556,0.707,0.831,0.924,0.981, 1,0.981,0.924,0.831,0.707,0.556,0.383,0.195}; uint ref[]={0,140,280,420,560,700,840,980,1120}; uchar cod[]={0x00,0x01,0x03,0x07,0x0f,0x1f,0x3f,0x7f,0xff}; uchar quan[16]={0}; uchar s; void reverse(uchar n)//倒序 { uchar i,j,k,l; float temp; for(i=0;i<n;i++) { real[i]=sample[i]; imag[i]=0; } l=n/2; j=l;//倒序起始序号 for(i=1;i<l;i++) { if(i<j) { temp=real[i]; real[i]=real[j]; real[j]=temp; } k=l; while((j>k)||(j==k)) { j=j-k; k=k/2; } j=j+k;//下一个倒序序号 } } void fft(uchar m,uchar n) { uchar l,b,j,p,k; float realtemp,imagtemp,temp; for(l=1;l<=m;l++) { b=1<<(l-1); for(j=0;j<b;j++) { p=j*(1<<(m-l));//系数 for(k=j;k<n;k=k+2*b) { realtemp=real[k]; imagtemp=imag[k]; temp=real[k+b]; real[k]=real[k]+real[k+b]*cosp[p]+imag[k+b]*sinp[p]; imag[k]=imag[k]+imag[k+b]*cosp[p]-real[k+b]*sinp[p]; real[k+b]=realtemp-real[k+b]*cosp[p]-imag[k+b]*sinp[p]; imag[k+b]=imagtemp-imag[k+b]*cosp[p]+temp*sinp[p]; } } } } void fftabs(uchar n)//取模 { uchar i; for(i=1;i<n;i++) real[i]=sqrt(real[i]*real[i]+imag[i]*imag[i]); } void quantization(uchar n)//量化 { uchar i,j; for(i=1;i<n;i++) { for(j=0;j<9;j++) { if((real[i]-ref[j])>0) quan[i]=j; } } } void delay() { uchar x,y; for(x=20;x>0;x--) for(y=255;y>0;y--); } void display() { uchar i; for(i=1;i<8;i++) { P1=~(1<<i); P0=cod[quan[i]]; delay(); } P1=0XFF;//关闭左面点阵 for(i=0;i<8;i++) { P3=~(1<<i); P2=cod[quan[i+8]]; delay(); } P3=0XFF;//关闭右面点阵 } void main() { P1ASF=0x01; ADC_CONTR=0xe0; TMOD=0X02; TH0=0XBD; TL0=0XBD; EA=1; ET0=1; TR0=1; EADC=1; while(1) { display(); if(TR0==0)//AD采集完32个数 { reverse(32); fft(5,32); fftabs(16); quantization(16); TR0=1; } } } void timer0() interrupt 1 { ADC_CONTR=0xe8; } void adc() interrupt 5 { ADC_CONTR=0xe0;//清AD中断标志位 sample[s++]=(ADC_RES<<2)|ADC_RESL; if(s==32) { s=0; TR0=0; } }