title: Expected a Declaration
body: <p>This is my first question (quite new to coding) so will try and include as much info as possible 'cos right now I'm stumped!</p>
  
  <p>I'm attempting to write code that will create a butterworth filter to fit user input specifications. I'm using Code Composer 4.</p>
  
  <p>Having google away 54 errors I have a persistent 1 left: </p>
  
  <pre><code>"expected a declaration" on line 27: if (n=1 &amp;&amp; hpf=0)
  </code></pre>
  
  <p>I have triple checked curly brackets, any ideas?</p>
  
  <p>EDIT:</p>
  
  <p>Hi again, thanks for all the help. Have sorted old problems and more since then but have hit a brick wall again; the code won't write over (or create if the file is deleted) the coffic.cof file. No errors appear but the file just remains the same. Any idea?</p>
  
  <p>P.S. sorry about the previous code layout - hopefully this is better:</p>
  
  <pre><code>#include "dsk6713_aic23.h"      //codec-DSK support file
  Uint32 fs=DSK6713_AIC23_FREQ_8KHZ;  //set sampling rate
  # include &lt;stdio.h&gt;
  # include &lt;math.h&gt;
  # include &lt;stdlib.h&gt; 
  #define pi 3.1415927
  #include "coffic.cof"
  
  void main()
  {
      double hpf, fs, fco, atn, fat, tp, k, ad, m, n, o, da, db, dc;
      FILE *fp;
      int c, d, e, f, g, h, i, q, r, s, t, u, v;
      hpf = 0;            //for a high-pass filter input 1, for a low-pass filter input 0
      fs = 8000;          //input samping frequency here
      fco = 2400;         //input cut-off frequency here
      atn = 17;           //input attenuation (dB) here
      fat = 3500;         //input the frequency of attenuation here
      tp = 1/fs;
      k = tan(pi*fco*tp);
      ad = tan(pi*fat*tp);
      m = (log10((pow(10,(atn/10)))-1))/(2*(log10(ad/k)));
      o = abs(m);
      n = ceil(o);
  
      da = 1.414;
      c = (pow(2,15)*k*k/(1+da*k+k*k));
      d = (pow(2,15)*2*k*k/(1+da*k+k*k));
      e = (pow(2,15)*k*k/(1+da*k+k*k));
      q = (pow(2,15)*(2-2*k*k)/(1+da*k+k*k));
      r = (pow(2,15)*(-1+k-k*k)/(1+da*k+k*k));
  
      fp = fopen("U:\DSK6713\Ivo\CSP\coffic.cof", "w");
      if (fp == NULL)
      {
          printf("Error. Unable to open coffic.cof");
          exit(0);
      }
  
      fprintf(fp, "int a[3]={%d, d%, %d};\n", c, d, e);
      fprintf(fp, "int b[3]={1, d%, %d};\n", q ,r);
      fprintf(fp, "int x[3]={0,0,0};\nint y[3]={0,0,0};\n");
  
      fflush(fp);
  
      fclose(fp);
  
      comm_intr();                   //init DSK, codec, McBSP
      while(1);                      //infinite loop
  }
  
  interrupt void c_int11()         //interrupt service routine 
  {
      short input;
      FILE *fp;
      fp = fopen("U:\DSK6713\Ivo\CSP\coffic.cof", "r");
      if (fp == NULL)
      {
          printf("Error. Unable to open coffic.cof");
          exit(0);
      }
  
      fclose(fp);
  
      x[2]=x[1];
      x[1]=x[0];
      y[2]=y[1];
      y[1]=y[0];
  
      input=input_sample();
      x[0]=input;
  
      y[0]=a[0]*x[0]+a[1]*x[1]+a[2]*x[2]+b[1]*y[1]+b[2]*x[2];     
  
      y[0]=y[0]&gt;&gt;15;                      
      input=(short)y[0];
      output_sample(input);   //output data  
      return;
  }
  </code></pre>