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main.c
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main.c
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/*
* main.c
*/
#include <DSP28x_Project.h>
#include "DSP_KB.h"
#include "Lab9.h"
#include "FPU.h"
#include <math.h>
void fft_init();
RFFT_F32_STRUCT fft;
#define FFT_SIZE 256
#define FFT_STAGES 8 //log base 2 (FFT_size)
//#pragma DATA_SECTION(sampleBuffer, "INBUFA");
static float sampleBuffer[FFT_SIZE];
static float outBuffer[FFT_SIZE];
float TwiddleBuffer[FFT_SIZE];
static float MagBuffer[FFT_SIZE/2];
static float SumSpectrum[FFT_SIZE/2];
static int sampleCount = 0;
static int sampleBufferFull = 0; //variable used to denote whether the buffer has been filled
interrupt void sampleGet_ISR(void);
void initBuffers();
unsigned long ISRvalue = &sampleGet_ISR;
int main(void) {
DisableDog();
CPUinit();
EALLOW;
outputEnable();
LCDinit();
LCDclear();
initADC();
DAC_init();
// SRAMwrite(0);
// SRAMaddress = 0x260000; //shouldn't need SRAM here
fft_init();
initBuffers();
timerINIT(ISRvalue, samplingRate);
while(1){
if(sampleBufferFull){
fft.InBuf = &sampleBuffer[0];
int i;
for(i = 0;i<FFT_SIZE;i++){
outBuffer[i] = 0;
}
for(i=0;i<FFT_SIZE/2;i++){
MagBuffer[i] = 0;
}
RFFT_f32(&fft);
//fft.MagBuf = &sampleBuffer[0];
RFFT_f32_mag(&fft);
sampleBufferFull = 0;
EINT;
}
else{
//do nothing
}
}
return 0;
}
void fft_init(){
fft.InBuf = &sampleBuffer[0];
fft.OutBuf = &outBuffer[0];
fft.CosSinBuf = &TwiddleBuffer[0];
fft.FFTSize = FFT_SIZE;
fft.FFTStages = FFT_STAGES;
fft.MagBuf = &MagBuffer[0];
RFFT_f32_sincostable(&fft);
}
interrupt void test_ISR(void){
unsigned int input = ADC_get();
DAC_set(input);
}
interrupt void sampleGet_ISR(void){
unsigned int input = ADC_get();
DAC_set(input);
sampleBuffer[sampleCount] = (float)input;
sampleCount++;
if(sampleCount == FFT_SIZE){
sampleCount = 0;
sampleBufferFull = 1;
DINT; //disables interrupts, if doesn't work can send to dummy interrupt vector
}
}
void initBuffers(){
int i,k;
for(i = 0; i<FFT_SIZE;i++){
sampleBuffer[i] = 0;
}
for(k = 0; i<FFT_SIZE/2;i++){
SumSpectrum[i] = 0;
}
}