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;}
Hi xingjunmarco,
You can state the details of the problems so that fellow members will be able to help you.
Yes, you can use it under µVision IDE and µVision Debugger.
For some part(s) of your program I will just give recommendations and it's up to you if you will do the modification. Here are the minor problems
float pi = 3.1416 ;
you can use
float pi = 3.14159265;
or
float pi = 3.1415927;
For some other issues, I decided to post them separately. If other members will give their comments the subject matters are already segregated so if you will reply be sure to do it in the appropriate post.
Ultimately, I recommend that you consider CMSIS, there is an elegant way of realizing your project.
Regards,
Goodwin
I am referring to your code. Regarding the LM3s8962 and evaluation board, I'm not sure, but Cortex-M3 is supported and LM3s8962 is a popular (albeit in NRND status already) MCU so most likely it's supported in µVision. To be sure, you have to verify in KEIL's website http://www2.keil.com/mdk5/uvision/ or in µVision if you already have it installed.