FFT.rar_visual c

#include "DSP281x_Device.h" // DSP281x Headerfile Include File #include "DSP281x_Examples.h" // DSP281x Examples Include File #include "f2812a.h" #include"math.h" #define PI 3.1415926 #define SAMPLENUMBER 1024 void InitForFFT(); void MakeWave(); //void FFT(float dataR[SAMPLENUMBER],float dataI[SAMPLENUMBER]); int INPUT[SAMPLENUMBER],DATA[SAMPLENUMBER]; int fWaveR[SAMPLENUMBER],fWaveI[SAMPLENUMBER],w[SAMPLENUMBER]; int sin_tab[SAMPLENUMBER],cos_tab[SAMPLENUMBER]; void FFT(int dataR[SAMPLENUMBER],int dataI[SAMPLENUMBER]) { int x0,x1,x2,x3,x4,x5,x6,x7,x8,x9,xx; int i,j,k,b,p,L; int TR,TI,temp; /********** following code invert sequence ************/ for ( i=0;i<SAMPLENUMBER;i++ ) { x0=x1=x2=x3=x4=x5=x6=x7=x8=x9=0; x0=i&0x01; x1=(i/2)&0x01; x2=(i/4)&0x01; x3=(i/8)&0x01;x4=(i/16)&0x01; x5=(i/32)&0x01;x6=(i/64)&0x01;x7=(i/128)&0x01;x8=(i/256)&0x01;x9=(i/512)&0x01; xx=x0*512+x1*256+x2*128+x3*64+x4*32+x5*16+x6*8+x7*4+x8*2+x9; dataI[xx]=dataR[i]; } for ( i=0;i<SAMPLENUMBER;i++ ) { dataR[i]=dataI[i]; dataI[i]=0; } /************** following code FFT *******************/ for ( L=1;L<=10;L++ ) { /* for(1) */ b=1; i=L-1; while ( i>0 ) { b=b*2; i--; } /* b= 2^(L-1) */ for ( j=0;j<=b-1;j++ ) /* for (2) */ { p=1; i=10-L; while ( i>0 ) /* p=pow(2,7-L)*j; */ { p=p*2; i--; } p=p*j; for ( k=j;k<1024;k=k+2*b ) /* for (3) */ { TR=dataR[k]; TI=dataI[k]; temp=dataR[k+b]; dataR[k]=dataR[k]+dataR[k+b]*cos_tab[p]+dataI[k+b]*sin_tab[p]; dataI[k]=dataI[k]-dataR[k+b]*sin_tab[p]+dataI[k+b]*cos_tab[p]; dataR[k+b]=TR-dataR[k+b]*cos_tab[p]-dataI[k+b]*sin_tab[p]; dataI[k+b]=TI+temp*sin_tab[p]-dataI[k+b]*cos_tab[p]; } /* END for (3) */ } /* END for (2) */ } /* END for (1) */ for ( i=0;i<SAMPLENUMBER;i++ ) { w[i]=sqrt(dataR[i]*dataR[i]+dataI[i]*dataI[i]); } } /* END FFT */ main() { int i; InitForFFT(); MakeWave(); for ( i=0;i<SAMPLENUMBER;i++ ) { fWaveR[i]=INPUT[i]; fWaveI[i]=0.0f; w[i]=0.0f; } FFT(fWaveR,fWaveI); for ( i=0;i<SAMPLENUMBER;i++ ) { DATA[i]=w[i]; } while ( 1 ); // break point } void InitForFFT() { int i; for ( i=0;i<SAMPLENUMBER;i++ ) { sin_tab[i]=sin(PI*2*i/SAMPLENUMBER); cos_tab[i]=cos(PI*2*i/SAMPLENUMBER); } } void MakeWave() { int i; for ( i=0;i<1024;i++ ) { INPUT[i]=sin(2*PI*128*i/SAMPLENUMBER)*1024;//+sin(2*PI*8*i/SAMPLENUMBER)*800; } }