spectrum_analyser.c

基于TMS320C5416平台的谱分析程序

          /* Result greater than or equal power_spectrum[i]*/
        }  
    }

  return ( result );
}

/*****************************************************************************/
/*                                                                           */
/* For compatibility with pcm3002 read / write, these variables must         */
/* be declared as Int16 or short int, rather than int.                       */
/*                                                                           */
/*****************************************************************************/

Int16 left_input;
Int16 left_output; 
Int16 right_input;
Int16 right_output; 
Int16 mono_input;

/*****************************************************************************/
/* UserTask()                                                                */
/*---------------------------------------------------------------------------*/
/*                                                                           */
/* The main user task.                                                       */
/*                                                                           */
/* Note that this task is not called by main(). It is scheduled by DSP/BIOS  */
/*                                                                           */
/*****************************************************************************/
 
void UserTask()
{
    DSK5416_PCM3002_CodecHandle hCodec;
    long i;
    unsigned int j;
    unsigned int switch_value;
    unsigned int temp;
          
    /* Start the codec */
    hCodec = DSK5416_PCM3002_openCodec(0, &setup);
 
    /* Display project details on StdOut. \n is important. */
 
    puts("TMS320C5416 DSK: Fast Fourier Transform to determine power spectrum of signal.\n");
   
    buffers_initialize(); 
          
    for ( i = 0 ; i < 12000000 ; i++ )
    {
    
      /* Read input multiple times and put into receive buffer */ 
    
       for ( j = 0 ; j < N ; j++)
         {
          /* Read left input channel */    
          while (!DSK5416_PCM3002_read16(hCodec, &left_input));

          /* Output to left output channel */       
          while (!DSK5416_PCM3002_write16(hCodec, left_output));
      
          /* Read right input channel */
          while (!DSK5416_PCM3002_read16(hCodec, &right_input));
      
          /* Output to right output channel */
          while (!DSK5416_PCM3002_write16(hCodec, right_output));
      
          /* Read user switches on DSK and display their meaning on Stdout. */
          switch_value = switch_status_display();

          /* Copy inputs straight to outputs */
          left_output = left_input;
          right_output = right_input;

          /* Generate mono signal from two input signals */
          mono_input = stereo_to_mono(left_input, right_input);

          /* Read next value into straight buffer */
          shuffle_and_read (mono_input);         
        

 
      }
      
      /* Copy input samples from receive buffer to y[] */
      copy_input_to_complex(); 

      /* Perforn FFT for specified number of points */
    
      FFT( y, N );          
   
      /* Determine power of outputs in y[] */ 
      calculate_output_power( y, &power_spectrum[0]);

      if ( 0 == switch_value)
       { 
        /* Use largest power spectrum to indicate output of CD player */
        temp = calculate_maximum_output_power();
        /* Display on bargraph */
        bargraph_6dB ( temp, temp ); 
       } 
      else if ( 1 == switch_value)
       { 
        /* Display lowest frequency components */
        spectrum_analyser_display( power_spectrum[1], power_spectrum[2],
                                   power_spectrum[3], power_spectrum[4] );
       }
      else if ( 2 == switch_value)
       { 
        /* Display lowest frequency components */
        spectrum_analyser_display( power_spectrum[5], power_spectrum[6],
                                   power_spectrum[7], power_spectrum[8] );
       } 
      else if ( 3 == switch_value)
       { 
        /* Display lowest frequency components */
        spectrum_analyser_display( power_spectrum[9], power_spectrum[10],
                                   power_spectrum[11], power_spectrum[12] );
       }
      else if ( 4 == switch_value)
       {
         bargraph_3dB ( power_spectrum[1], power_spectrum[1] );
       }               
      else if ( 5 == switch_value)
       {
         bargraph_3dB ( power_spectrum[2], power_spectrum[2] );
       }         
      else if ( 6 == switch_value)
       {
         bargraph_3dB ( power_spectrum[3], power_spectrum[3] );
       }         
      else if ( 7 == switch_value)
       {
         bargraph_3dB ( power_spectrum[4], power_spectrum[4] );
       }         
      else if ( 8 == switch_value)
       {
         bargraph_3dB ( power_spectrum[5], power_spectrum[5] );
       }        
      else if ( 9 == switch_value)
       {
         bargraph_3dB ( power_spectrum[6], power_spectrum[6] );
       }        
      else if ( 10 == switch_value)
       {
         bargraph_3dB ( power_spectrum[7], power_spectrum[7] );
       }         
      else if ( 11 == switch_value)
       {
         bargraph_3dB ( power_spectrum[8], power_spectrum[8] );
       }         
      else if ( 12 == switch_value)
       {
         bargraph_3dB ( power_spectrum[9], power_spectrum[9] );
       }         
      else if ( 13 == switch_value)
       {
         bargraph_3dB ( power_spectrum[10], power_spectrum[10] );
       }         
      else if ( 14 == switch_value)
       {
         bargraph_3dB ( power_spectrum[11], power_spectrum[11] );
       }         
      else if ( 15 == switch_value)
       {
         bargraph_3dB ( power_spectrum[12], power_spectrum[12] );
       }         
       
     }

    /* Finished processing. Close the codec */
    DSK5416_PCM3002_closeCodec(hCodec);
    
    puts("TMS320C5416 DSK has terminated\n");
}

/*****************************************************************************/
/* main()                                                                    */
/*****************************************************************************/

void main()
{
    /* Initialize the board support library                         */
    /* There is no need to initialize the DIP switches and the LEDs */
    
    DSK5416_init();
    
    /* All other functions are scheduled by DSP/BIOS */
}

/******************************************************************************/
/* End of spectrum_analyser.c                                                 */
/******************************************************************************/