FFT Uncertainty

[moccasinmatt]

How would I calculate the FFT uncertainty based upon the sampling frequency and the number of samples. For our project, the number of samples is 128 and the sampling frequency is 2048. This would seem to say that the FFT resolution is 16 Hz and the uncertainty is 8 Hz, but the majorPeak is far more accurate than plus or minus 8 Hz. Why is that? and how can I determine the uncertainty?

[kosme]

majorPeak() interpolates the highest frequency, which is why you see an accuracy better than ±8Hz. Therefore, the returned value is an estimate. You could search manually for the highest bin in vReal and calculate its frequency based on the index number.