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Hi Community,
I have a set of FFT codes that is suppose to create an array of number after processing the incoming signal.
When I build my codes in code composer studio it was successfully built.
However, when I run it on debug mode it face problems.
The purpose of my project is to simply program a set of FFT algorithm in c, and allow my LM3s8962 micro-controller to process the incoming signal(Voice or sound).
I have another question, can I use the algorithm to run it in my keil uvision, since the keil uvision has the spectrum/logic analyser which I can see the frequency spectrum.
I will attach my algorithms here, if any kind hearted soul spot any mistakes in my algorithm please enlighten me.
/* * main.c */#include <stdio.h>#include <math.h>#include <stdbool.h>#include <stdint.h>#include "inc/hw_memmap.h"#include "inc/hw_types.h"#include "inc/hw_ints.h"#include "driverlib/sysctl.h"#include "driverlib/adc.h"#include "driverlib/interrupt.h"#include "driverlib/gpio.h"#include "driverlib/pin_map.h"#include "grlib/grLib.h"#include "grlib/grLibDriver.h"
short sample[8];
#pragma vector=unused_interruptsinterrupt void user_trap_function(void) //ISR to handle the end of sampling interrup, being the only enabled interrupt{ int df = 15625; //fs/N = 125000/8 int Re[8]; int Im[8]; int Ampl[8]; int fr[8]; int N = 8; //number of samples x[N] = (short)sample; // convert sample values to short integers for computation int out[2] = {0,0}; //init Re and Im results int j=0; for (j = 0; j < N; j++){ dft(x,j,out); //call DFT function Re[j] = out[0]; Im[j] = out[1]; //collect real and imaginary parts Ampl[j] = ((Re[j]^2)+(Im[j]^2))^(1/2); fr[j] = df*j;
long lX1 = (long)Ampl[j]; long lX2 = (long)Ampl[j]+1; long lY = (long)fr[j]; long ulValue = 128;
void LineDrawH (pvDisplayData, lX1, , lX1, lY, ulValue);
}
int M = 0;unsigned long sample[8]
void LineDrawH (void *pvDisplayData, long lX1, long lX2, long lY, unsigned long ulValue);
void ADC_init( void ) { SYSCTL_RCGC0_R |= SYSCTL_RCGC0_ADC; // Enable the clock to the ADC module SYSCTL_RCGC0_R |= SYSCTL_RCGC0_ADCSPD125K; // Configure the ADC to sample at 125KS/s ADCSequenceDisable(ADC_BASE, 0); // Disable sample sequences 0 ADCSequenceConfigure(ADC_BASE, 0, ADC_TRIGGER_PROCESSOR, 1); // Configure sample sequence 0: processor trigger, priority = 1 IntPrioritySet(INT_ADC0SS0,0); // Set SS0 interrupt priority to 0 ADCSequenceStepConfigure(ADC_BASE, 0, 0, ADC_CTL_CH0); // Configure sample sequence 0 to sample external input ADCSequenceStepConfigure(ADC_BASE, 0, 1, ADC_CTL_CH0); ADCSequenceStepConfigure(ADC_BASE, 0, 2, ADC_CTL_CH0); ADCSequenceStepConfigure(ADC_BASE, 0, 3, ADC_CTL_CH0); ADCSequenceStepConfigure(ADC_BASE, 0, 4, ADC_CTL_CH0); ADCSequenceStepConfigure(ADC_BASE, 0, 5, ADC_CTL_CH0); ADCSequenceStepConfigure(ADC_BASE, 0, 6, ADC_CTL_CH0); ADCSequenceStepConfigure(ADC_BASE, 0, 7, ADC_CTL_CH0 | ADC_CTL_IE | ADC_CTL_END); //set interrupt flag after the seventh step ADCIntEnable(ADC_BASE, 0); // Enable the interrupt for sample sequence 0 IntEnable(INT_ADC0SS0); // Enable SS0 Interupt in NVIC M+=M; // integer to detect if ADC is initialized}
unsigned long getADC0(void){
ADCProcessorTrigger(ADC0_BASE, 0); //initiate sampling while(!ADCIntStatus(ADC0_BASE, 0, false)); //monitor interrupt flag for completion of sampling ADCSequenceDataGet(ADC0_BASE, 0, sample); //assign samples to global variable, sample
return sample; //return sample to calling function}
int dft(long *x, short k, int *out) //DFT function { int sumRe = 0; //init real component int sumIm = 0; //init imaginary component int i = 0; int N = 8; float pi = 3.1416 ; float cs = 0; //init cosine component float sn = 0; //init sine component for (i = 0; i < N; i++) //for N-point DFT { cs = cos(2*pi*(k)*i/N); //real component sn = sin(2*pi*(k)*i/N); //imaginary component sumRe += x[i]*cs; //sum of real components sumIm -= x[i]*sn; //sum of imaginary components } out[0] = sumRe; //sum of real components out[1] = sumIm; //sum of imaginary components
return(out); }int main(void) { if (M>0){ ADC_init(); //initialize ADC module if not already initialized } getADC0(); //start conversion. Interrupt flag will be set after sampling and this functioned called again after ISR executes return 0;}
In main there is this block
if (M>0){ ADC_init(); //initialize ADC module if not already initialized}
if (M>0){
ADC_init(); //initialize ADC module if not already initialized
Here, ADC_init() will never be executed. The reason is
int M = 0;
you initialized M to 0 in its declaration. I'll leave the correction to you to conform to your preferences. Besides, you have a reason for putting ADC_init() in the if block.