File content as of revision 60:a83a5a34050b:

#include "mbed.h"
#include "arm_math.h"
#include "arm_const_structs.h"

const int FFT_SIZE = 32;
int sampleCounter;
float samples[FFT_SIZE*2];
float magnitudes[FFT_SIZE];
//int SAMPLE_RATE_HZ = 10000;

//static const float testData[FFT_SIZE/2];       //vår test data
float testData = {10, 20, 30, 40, 50, 60, 70, 80, 10, 20, 30, 40, 50, 60, 70, 80,10, 20, 30, 40, 50, 60, 70, 80, 10, 20, 30, 40, 50, 60, 70, 80};

void samplingBegin(){
    sampleCounter = 0;
    //sätt hårdvaru inställningar här om det behövs
}

void samplingCallback() {
    //läs data
    samples[sampleCounter] = testData[sampleCounter];
    // sätter imaginär till 0
    samples[sampleCounter + 1] = 0.0;
    sampleCounter += 2;
    if (sampleCounter >= FFT_SIZE *2 ) {
        //här är sampling klar, buffert är full
        //skriv hårdvaru kod här   
}    

bool samplingIsDone() {
    return (sampleCounter >= FFT_SIZE*2);
}

// main() runs in its own thread in the OS
int main() { 

samplingBegin();

S = & arm_cfft_sR_f32_len32;



while(1) {
    if(samplingIsDone()){
        arm_cfft_f32(S,samples,0,1);
        arm_cmplx_mag_f32(samples,magnitudes,FFT_SIZE);
        samplingBegin();
    }

}