File content as of revision 0:888888c9f065:

#include "mbed.h"
#include <ctype.h>
#include "FastAnalogIn.h"
#include "arm_math.h"
#define NUM_TAPS 51
FastAnalogIn audioin(PTC2); //Analog in
AnalogOut audioout(PTE30); //Analog out
Ticker sampleing; //ticker is a class that automatically interrupts the processor on an interval
DigitalOut l(PTA1);
DigitalOut set1(LED1);
DigitalOut set2(LED2);
DigitalIn state(PTA2);
const int num_samples = 512; //512 max! kmc
const int num_buffers = 3;
int samplecounter = 0;
int fill_index = 0;
int dump_index = 1;
int ready_index =2;
float32_t buffer[num_buffers][num_samples];
arm_fir_instance_f32 H,L;

static float32_t firStateF32[1 + NUM_TAPS - 1];
float32_t  *inputF32, *outputF32;
/* ----------------------------------------------------------------------
** FIR Coefficients buffer generated using fir1() MATLAB function.
** fir1(28, 6/24)
** ------------------------------------------------------------------- */

 const float32_t firCoeffs32_H[NUM_TAPS] = {
-0.0000080878311f,   0.00003923656432f,    -0.000061039638221f, -0.00003695668356985f,   0.000275668560418687f,    -0.000327280297262495f,   
-0.000260129744371785f,   0.00116157181055702f, -0.000923953609936865f,   -0.00133518222306195f,    0.00349543690781629f, 
-0.00150896657945131f,    -0.00479968490025620f,    0.00809627752995577f, -0.000496933275084586f,  -0.0132944668070009f, 0.0150641815132129f,  
0.00598396310662075f, -0.0310875990306542f, 0.0231130218762105f,  0.0273325707514090f,  -0.0702585024688767f, 0.0297114875214292f,  
0.115565099312860f,   -0.288244540649423f,  0.365609759681161f,   -0.288244540649423f,  0.115565099312860f,   0.0297114875214292f,  
-0.0702585024688767f, 0.0273325707514090f,  0.0231130218762105f,  -0.0310875990306542f, 0.00598396310662075f, 0.0150641815132129f,  
-0.0132944668070009f, -0.000496933275084586f,   0.00809627752995577f, -0.00479968490025620f,  -0.00150896657945131f,    0.00349543690781629f,
 -0.00133518222306195f,  -0.000923953609936865f,  0.00116157181055702f, -0.000260129744371785f,   -0.000327280297262495f,
 0.000275668560418687f,  -0.0000369566835698504f,   -0.00006103963822183f,   0.0000392365643258656f,    -0.00000808783111344f
};

const float32_t firCoeffs32_L[NUM_TAPS] = {
-0.000471676005294967f,   -0.000869941110733902f,   -0.00136615751059969f,    -0.00192713332921617f,    -0.00249683488334566f,    
-0.00299588766189560f,    -0.00332345379822847f,    -0.00336168772922327f,    -0.00298271993668161f,    -0.00205784383868562f,    
-0.000468311685565155f,   0.00188308797184820f, 0.00506066745872936f, 0.00908576885361775f, 0.0139290391946988f,  0.0195059759543063f,  
0.0256764342311968f,  0.0322484706002718f,  0.0389865257052826f,  0.0456235534497802f,  0.0518763277757713f,  0.0574628369693583f,  
0.0621204442047146f,  0.0656233774164507f,  0.0677981261749183f,  0.0685354696461944f,  0.0677981261749183f, 0.0656233774164507f,  
0.0621204442047146f,  0.0574628369693583f,  0.0518763277757713f,  0.0456235534497802f,  0.0389865257052826f,  0.0322484706002718f,  
0.0256764342311968f,  0.0195059759543063f,  0.0139290391946988f,  0.00908576885361775f, 0.00506066745872936f, 0.00188308797184820f, 
-0.000468311685565155f,   -0.00205784383868562f,    -0.00298271993668161f,    -0.00336168772922327f,    -0.00332345379822847f,    
-0.00299588766189560f,    -0.00249683488334566f,    -0.00192713332921617f,    -0.00136615751059969f,    -0.00086994111073390f,   
-0.000471676005294967f

};



int i,k;

void samplingCallback()
{
    //e = not(e);
    buffer[fill_index][samplecounter] = audioin;
    audioout = buffer[dump_index][samplecounter];
    samplecounter++;
    if(samplecounter >= 511) {
        samplecounter = 0;
        //l= not(l);
        ready_index = fill_index;
        if(++fill_index >= num_buffers) {
            fill_index = 0;
        }
        if(++dump_index >= num_buffers) {
            dump_index = 0;
        }
    }

}
void getfilter(){
        if(state == 1){
            arm_fir_f32(&H, inputF32 , outputF32, 1);
            set1 = 1;
            set2 = 0;
        }
        else{
            arm_fir_f32(&L, inputF32 , outputF32, 1);
            set1 = 0;
            set2 = 1;
        }
}    
    

void samplingBegin()
{
    //ticker_timing = 100000/sample_rate;
    samplecounter = 0;
    sampleing.attach_us(&samplingCallback, 125); //sample rate 40k 25, 45k 22, 50k,20
}

bool samplingisdone()
{
    //c = not(c);
    return samplecounter >= 510;
}

////////////////////////////////////////////////////////////////////
// Buffer Zeroing
////////////////////////////////////////////////////////////////////
void zerobuffers()
{
    for(i=0; i<=num_buffers; i++) {
        for(k=0; k<num_samples; k++) {
            buffer[i][k] = 0.0;
        }
    }
}


int main()
{

    
    
    //getfilter();
    samplingBegin();
    //button.rise(&getfilter);
    //getfilter();
    arm_fir_init_f32(&H, NUM_TAPS, (float32_t *)&firCoeffs32_H[0], &firStateF32[0], 1);
    arm_fir_init_f32(&L, NUM_TAPS, (float32_t *)&firCoeffs32_L[0], &firStateF32[0], 1);
    while(1) {
        if(samplingisdone()) {
            l = 1;
            inputF32 = &buffer[ready_index][0];
            outputF32 = &buffer[dump_index][0];
            getfilter();
            
            l=0 ;
        }
    }
}