Chris Anderson @chrisanderson1973@librem.one

Analog Device's BF706 reference design bring-up: The audio pass-through and filter demo's worked great, and this platform is way ahead of the STM32 platform I used last year. This looks like a good module to use for prototyping distortion, reverb, filters, octave, etc. We'll how it goes.

The composer app effort is continuing. I've cracked the Apple Audio Unit code, and now I see that there is an easy path to integrate Audio Units into my own apps. This is going to be a Mac and iPad app, I think.

Working on AudioUnit Extensions for Mac and iPad. Turns out, it is kind of fun. I am building a synth module (which would be a re-imagined AnaddrSynth) for a new DAW I am working on.

Another post on this new direction: I'm building a performance app from Mac and iPad. It may be more like a digital audio workstation, and it may even be more like a lot plugins placed together, for software like Logic Pro on iPad.

Another swing of the pendulum, and I am looking into macOS/iPadOS apps once again. I have a much better grasp of Core Audio this time (versus 2011-2014 and 2018), and I will probably refactor AnaddrSynth completely and, of course, introduce a new app.

Cool work day - digging into how C++ works.... Untangling dynamically linked libraries and setting class pointers.... Basically, exposed variables, per name, need to match in terms of data types. I just overlooked the obvious. :D

A new direction - sorta.... I am looking into making a looper for recording audio. #problemsolving #reinventingthewheelprobably

More work with the iMX8 platform to try and mold it into an audio effects and/or digital audio workstation. Some quick tests recently have shown that USB audio is a little slow on the iMX8, in that the set up has a noticeable delay and that the USB interface doesn’t quite keep up. That is, at least with the port audio stack. So, the other option is to run analog in/out on the board, and have it work more like a deluxe effects box. The analog in sounds great. An analog out test is next.

Still working on Linux audio on the Toradex iMX8 platform.....

Today, I made a first stab at a recording app for the coming iMX8-based DAW system. The audio recording/playback set up is the very fist step. Today, I was able to record some improv off my Ibanez!

Nice bit of audio work and embedded Linux work tonight. I managed to have the Linux sound framework working, taken from a Yocto build. It was enough to instantiate the audio card interfaces, including USB audio, and even run audio playback through HDMI and a DUET USB audio interface.

More work on my power amplifier design tonight. I added an auxiliary output that is available after any gain/distortion and reverb, and before the output (power) stage.

Looking into new DSP platforms, rather than the very minimal STM32F series I researche di nthe fall.... Starting with the Cyclone V FPGA platform, using the Quartus Prime Lite Edition.

I've gotten as far as designing the printed circuit board, including the power supplies and power amplifier stage!

A starting design for a 100W guitar amplifier, complete with distortion and reverb. I need to add an auxiliary out circuit, as well. Looking good!

Turns out, I like building stuff. 100W amplifier coming right up.

Some EE work this morning and in the last few days. Looking into building a guitar amplifier!

A favorite software technique I use: dynamically loading libraries and using function pointers to access the loaded library. Works in just about any contact in C/C++ and I have used it to make projects simpler to manage, and faster to compile. It's also very useful for building plugins.

More work tonight on the embedded Linux platform. I am building my custom Qt app and Audacity, together, on a Weston (Wayland) reference compositor. The goal is to bring up Audacity on the board and work with the audio interfaces.

Continuing work on a Linux-based effects system....I had to move up from anything STM32-based. There is simply too much efficiency in using Linux.