Various people urged me to post this. My doctoral thesis is due a couple of days from today and I have problems with CASPER stuff that worry both my advisor and me. We have two spectrometers: one with lower resolution but all the features I wanted and one based on CASPER Tutorial 3 but transformed into a higher-resolution spectrometer.
The lower-resolution, full-featured one uses a simple_bram_vacc but the output is a pattern which forms groups of four data words in a pattern that repeats through the entire output. The values don't exactly repeat, but the overall pattern repeats. For example, sometimes the first value is large, the second is small and the last two values in each group of four are medium (neither large nor small). I believe this is a timing issue. The higher-resolution spectrometer uses a Bee2 ADC (iADC). NO matter what signal we put inot this spectrometer, the output FFT has the same amplitude. This prevents us from labelling the vertical axis with units. The thesis committee has already said graphs without proper units are not acceptable. Is the problem caused by an Automatic Gain Control or could this problem also be a timing issue with the accumulator? Any comments? People have been asking questions before I can even finish typing this message.
