Progress
This week is the last week of work, and has been spent on getting things ready for the final demo.
For the actual synthesizer, I spent this week debugging several issues with the DAC module, did some last minute tuning of effects, and worked on the extra looping feature that we can hopefully have by Monday.
For the DAC, we realized that one of the big sources of noise in our system was incorrect samples coming out of the physical DAC chip, and after many hours of debugging, we realized that the timing of our DAC module on the FPGA may be violating the required setup tim internal to the DAC. Further debugging also revealed that occasionally the sample would change partway through the serial data transmission, leading to completely wrong samples being fed into the DAC. Finally, the very last bug was that we found out that the sine wavetable was missing a sample entry, leading to audible periodic noise. Now there is very little noise audible, which makes me very happy.
For the wavetables, I finished writing a Python script that would transform .wav files into MIF files of the correct format and sample rate to work with our synthesizer. For the complex waveforms, we found a very extensive database of complex wavetables online, and we chose our 4 favorite ones to use in the synthesizer.
For effects, I did some last minute tuning to a lot of the effects, tweaking parameters used in the reverb and unison, as well as adding a phase difference effect in the wavetable blending, which will hopefully improve the blending effect by adding another parameter.
I continued work on the looping module, though I am unsure whether it can be tested and ready by Monday. A lot of my time this week that I had hoped to spend on looping
Finally, I spent a lot of time this week working on the final presentation and poster.
Hopefully everything can be wrapped up in the next day, and we’ll have a good demo. All the noise is gone now, so its just polishing from here on out. I feel pretty good about where we stand now, since my biggest worry was that we couldn’t get rid of the noise and that issue is solved.
