Chris Anderson @chrisanderson1973@librem.one

Ona plane flight, coming back from CA, I thought about the interview with Markus Reuter and his process for creating music. This gave me a fairly grand idea, and mostly because I have no real idea how he put together his workflow…..So, it looks like I am building a looper-DAW.

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

A quick update: The ALSA audio project for Linux has a utility called alsaloop, which provides an audio loop back through “capture” and “playback” interfaces. On the Toradex Apalis iMX8 platform, using alsaloop, I was able to play an instrument in a loopback configuration with an analog “line in” and a headphone jack. This is a huge deal, because it allows for an analog-in to digital to analog out path, and a great embedded device for building a complex effects processor!👍 More work to follow!

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.

@SteveWhitty A great one, indeed!

@SteveWhitty Great to see some Rush fans on Mastodon! I cannot stop listening to Rush (going on since 1987), and Permanent Waves is one of my favorites. My favorite tune off the album is probably Natural Science, but The Spirit of Radio is a close second.