[SOLVED] Help!!! Wrong results while using FFT in MikroC Pro for dsPIC

[karanbanthia]

Hi,
I am trying to use the FFT library in mikroC to calculate the frequency of input signal. The code gets complied but I am getting wrong and random results. The calculated freq does not match the input simulated sine wave. Following are the details of my code -
Sampling freq = 1KHz
Signed Fractional Data Output from ADC. Sampling done using timer 3 Interrupt.
I am performing 128 point DFT.
Following is a part of my main code where calculation is done :

if(start_calc == 1)
  {
   FFT(log2N, TwiddleCoeff_128, stored_reading);
   BitReverseComplex(log2N, stored_reading);
   if(i==0)
   {
    //sum[i] = 0;
    i = i+1;
    k = k+2;
   }
   else if(i<=((num_samples/2)-1))
   {
    test_pin = 1;
    re = stored_reading[k++];
    im = stored_reading[k++];
    rer = Q15_Itof(re);
    imr = Q15_Itof(im);
    tmpr = rer * rer;
    rer = tmpr;
    tmpr = imr * imr;
    imr = tmpr;
    tmpr = sqrt(rer + imr);
    //rer  = tmpr * 128.;
    //sum[i] = rer;
    //sum[i] = tmpr;
    if(tmpr> maximum)
    {
     maximum = tmpr;
     peak_freq_bin = i;
    }
    else;
    i = i+1;
   }
   else
   {
    test_pin = 0;
    //Vector_Max(sum,(num_samples/2),&peak_freq_bin);
    peak_freq = peak_freq_bin * 8;
    WordToStr(peak_freq,txt);
    send_string(txt);
    start_calc = 0;
    //test_pin = 0;
    i = 0;
    k = 0;
    maximum = 0;
    peak_freq_bin = 0;
    SR = 0x0000;         // Set CPU Priority to 0
   }
  }
  else;

What is wrong with these calculations??