February 16, 2021

It’s been a long time since the last update, largely due to having to prep our house for sale. But in spite of time spent painting, refinishing floors and replacing cabinets and fixtures, there has been steady software “refactoring” for the ADAU1701 code. As noted in other posts, my engineering background is more hardware and systems than software, and all of the initial code to control the ADAU1701 started out as as assembly language, written for the 68HC08 series microprocessors. Some of these devices only had 256 bytes of RAM to work with, which doesn’t support modern programming practices of modularity, decoupling and code reuse. I had “translated” this assembly code into Arduino C and although it worked, it was difficult to maintain and not something I could share with others.

The code that I was using these past years relied heavily on globally defined structures and enumerations and look-up tables, and refactoring this code into logically layered library calls proved to be much more difficult and time consuming than I expected. But much of this code is now working, and the code is far more maintainable and is “shareable”. I’ll be writing much more about this in the articles, and post updates as this effort is finalized.

I’ve also got a number of new DSP hardware projects lined up, but I’ve been putting them off until this code update is done. This software redesign has been a much bigger challenge than I expected, but I’m at the point where I’m coasting downhill rather than climbing. The house refurbishment is still going to take up most of my time, but even with those chores, I should be able to make more frequent updates on these pages.

3 thoughts on “February 16, 2021”

    1. Hi Steve. Fancy meeting you here :).
      I’ve got a second-generation version of that 22-channel amplifier for line arrays waiting to be debugged, but it’s been sitting for about 2 years now. I set it aside until I finished refactoring the microprocessor code because it was getting too difficult to maintain all the different “flavors” of DSP code. But that effort is almost done, so maybe I’ll finally be able to make some more line array amps. That prototype line array described in one of the articles turned out better than I expected, and we are using it at the cabin, with an optical switch to select between the internal WiFi modules and the TV. I’d really like to build at least one more prototype and then try a “high-end” version.

      1. I miss our speaker discussions. Don’t remember where we left it, but I phase in and out of the hobby. Maybe I’m phasing back in. I built the cabinet for a giant CBT center channel speaker, but never finished it. I still have loads of little 1″ drivers, 3″ Tang Bands, and 6 1/2″ mid woofs. I also was interested in the SEOS horn stuff, so I have lots of horns and horn drivers. I bought some of the Celestion 15″ PA speakers that Parts Express had some years ago. My next project might be a “Cheap Thrills” set-up. I also have some RCF horns and EAW 2″ drivers. Are you selling the house in Reston or somewhere else? I don’t think I have your e-mail.

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