FIR Filter Low pass/High pass (LP/HP) Using Kaiser window

Aim: To verify FIR Filter Low pass/High pass (LP/HP) Using Triangular window

SOFTWARE REQUIREMENTS:

Operating System – Windows XP

Constructor - Simulator

Software – Code Composer 3.1v,6713DSK Diagnostics

HARDARE REQUIREMENTS:

TMS320C67XXDSP KIT / example TMS320C6713DSP KIT

USB cable

Power Supply +5v

1.Kaiser window (High pass)

Program:

include "filtercfg.h"
#include "dsk6713.h"
#include "dsk6713_aic23.h"
#include "stdio.h"


//float filter_coeff[ ]={0.000050,0.000223,0.000520,0.000831,0.000845,
//      -0.000000,-0.002478,-0.007437,-0.015556,-0.027071,
//      -0.041538,-0.057742,-0.073805,-0.087505,-0.096739,
//       0.899998,-0.096739,-0.087505,-0.073805,-0.057742,
//      -0.041538,-0.027071,-0.015556,-0.007437,-0.002478,
//                    -0.000000,0.000845,0.000831,0.000520,0.000223,
//                                                           0.000050};
                                                //FIR High pass Kaiser filter pass band range 400Hz-3.5KHz

//float filter_coeff[ ]={0.000000,-0.000138,-0.000611,-0.001345,-0.001607,
//      -0.000000,0.004714,0.012033,0.018287,0.016731,
//       0.000000,-0.035687,-0.086763,-0.141588,-0.184011,
//       0.800005,-0.184011,-0.141588,-0.086763,-0.035687,
//       0.000000,0.016731,0.018287,0.012033,0.004714,
//      -0.000000,-0.001607,-0.001345,-0.000611,-0.000138,
//       0.000000};
                                                   //FIR High pass Kaiser filter pass band range 800Hz-3.5KHz

float filter_coeff[ ]={-0.000050,-0.000138,0.000198,0.001345,0.002212,-0.000000,
   -0.006489,-0.012033,-0.005942,0.016731,0.041539,0.035687,
   -0.028191,-0.141589,-0.253270,0.700008,-0.253270,-0.141589,
   -0.028191,0.035687,0.041539,0.016731,-0.005942,-0.012033,
    -0.006489,-0.000000,0.002212,0.001345,0.000198,-0.000138,
    -0.000050};
                                               //FIR High pass Kaiser filter pass band range 1200Hz-3.5KHz



//static short int  in_buffer[100];

DSK6713_AIC23_Config config={0x0017,0x0017,0x00d8,0x00d8,0x0011,0x0000,0x0000,0x0043,0x0081,0x0001};

void main( )
{
 DSK6713_AIC23_CodecHandle hCodec;
 Uint32 l_input, r_input,l_output, r_output;
 DSK6713_init();
 hCodec = DSK6713_AIC23_openCodec(0, &amp;config);

 DSK6713_AIC23_setFreq(hCodec, 1);

 while(1)
 {
      while(!DSK6713_AIC23_read(hCodec, &amp;l_input));

   while(!DSK6713_AIC23_read(hCodec, &amp;r_input));
   
     l_output=(Int16)FIR_FILTER(&amp;filter_coeff ,l_input);
              r_output=l_output;
               
      while(!DSK6713_AIC23_write(hCodec, l_output));
       
      while(!DSK6713_AIC23_write(hCodec, r_output));
 }

DSK6713_AIC23_closeCodec(hCodec);
}

signed int FIR_FILTER(float * h, signed int x)
{
int i=0;
signed long output=0;
static short int  in_buffer[100];
in_buffer[0] = x;

for(i=30;i>0;i--)
in_buffer[i] = in_buffer[i-1];

for(i=0;i<32;i++)
output = output + h[i] * in_buffer[i];
//output = x;
return(output);
}

Expected Output: Observed the output in CRO with respect to input signal, it pass the signal at range of pass band frequency 1200-3.5KHz,and attenuate at other than pass band frequency

2. Kaiser window (Low pass)

PROGRAM CODE:

#include "filtercfg.h"
#include "dsk6713.h"
#include "dsk6713_aic23.h"
#include "stdio.h"

//float filter_coeff[]={-0.000019,-0.000170,-0.000609,-0.001451,-0.002593,
//       -0.003511,-0.003150,0.000000,0.007551,0.020655,
//        0.039383,0.062306,0.086494,0.108031,0.122944,
//                   0.128279,0.122944,0.108031,0.086494,0.062306,
//        0.039383,0.020655,0.007551,0.000000,-0.003150,
//       -0.003511,-0.002593,-0.001451,-0.000609,-0.000710,
//       -0.000019};
                                                         // kaiser low pass fir filter pass band range 0-500Hz

//float filter_coeff[]={-0.000035,-0.000234,-0.000454,0.000000,0.001933,
//                                                    0.004838,0.005671,-0.000000,-0.013596,-0.028462,
//                                                  -0.029370,0.000000,0.064504,0.148863,0.221349,
//                                                    0.249983,0.221349,0.148863,0.064504,0.000000,
//                                                  -0.029370,-0.028462,-0.013596,-0.000000,0.005671,
//                                                    0.004838,0.001933,0.000000,-0.000454,-0.000234,
//                                                  -0.000035};
                                                // kaiser low pass fir filter pass band range 0-1000Hz

float filter_coeff[]={-0.000046,-0.000166,0.000246,0.001414,0.001046,
                                                  -0.003421,-0.007410,0.000000,0.017764,0.020126,
                                                  -0.015895,-0.060710,-0.034909,0.105263,0.289209,
                                                    0.374978,0.289209,0.105263,-0.034909,-0.060710,
                                                   -0.015895,0.020126,0.017764,0.000000,-0.007410,
                                                   -0.003421,0.001046,0.001414,0.000246,-0.000166,
                                                   -0.000046};
                                                //Kaiser low pass fir filter pass band range 0-1500Hz


//static short int  in_buffer[100];

DSK6713_AIC23_Config config={0x0017,0x0017,0x00d8,0x00d8,0x0011,0x0000,0x0000,0x0043,0x0081,0x0001};
void main( )
{
 DSK6713_AIC23_CodecHandle hCodec;
 Uint32 l_input, r_input,l_output, r_output;
 DSK6713_init();
 hCodec = DSK6713_AIC23_openCodec(0, &amp;config);

 DSK6713_AIC23_setFreq(hCodec, 1);

 while(1)
 {
      while(!DSK6713_AIC23_read(hCodec, &amp;l_input));

   while(!DSK6713_AIC23_read(hCodec, &amp;r_input));
   
     l_output=(Int16)FIR_FILTER(&amp;filter_coeff ,l_input);
              r_output=l_output;
               
      while(!DSK6713_AIC23_write(hCodec, l_output));
       
      while(!DSK6713_AIC23_write(hCodec, r_output));
 }

DSK6713_AIC23_closeCodec(hCodec);
}

signed int FIR_FILTER(float * h, signed int x)
{
int i=0;
signed long output=0;
static short int  in_buffer[100];
in_buffer[0] = x;

for(i=30;i>0;i--)
in_buffer[i] = in_buffer[i-1];

for(i=0;i<32;i++)
output = output + h[i] * in_buffer[i];
//output = x;
return(output);
}

Expected Output: Observed the output in CRO with respect to input signal, it pass the signal at range of pass band frequency 0-1500KHz, and attenuate at other than pass band frequency.

Updated
Feb 04, 2020
Views
1,146