Covoder - An audio DSP Demonstrator for the ESP32 and PCM5102

[bodeplot]

Hello again

I don’t seem to come on here much except when announcing a project. Apologies.

For the past year, I have been working on my very first Arduino project. Thanks to a good friend (wotnot), he has dragged me kicking and screaming into the new era of easy to use development environments. Using an Espressif Systems ESP32 and a PCM5102 DAC, I successfully produced an audio synthesiser demonstration using the Arduino development environment. Here is a demonstration of covoder on vimeo:



I wanted an application that would push the limits of this very powerful and cheap 32 bit micro, plus explore some of its features. So, I choose to implement a speech channel vocoder. Like an archaeological dig on Tony Robinson’s “Time Team” show, I effectively reversed engineered the process with nothing more than a wikipaedia description as a guide:

en.wikipedia.org/wiki/Vocoder

So this was the challenge; to make a working product based on a wikipaedia description, plus adding in a few other cool effects as well. Fingers crossed, the whole thing would run on the ESP32 with no resource starvation issues. So, this project was pretty much an exploratory one. It turned out a success

I hope you enjoy my little vocoder demo

J

[loopyloo]

Pretty cool. Well done.

[wotnot]

Full credit to bodeplot I give here ~ I was merely a facilitator. During the early days of our email collaboration, I sort of twigged he'd somehow 'missed out' on how/where the small microprocessor open market had gotten to, and what sorts of IDE and hardware supports were out there now. I know it sounds somewhat silly saying it today, but the same thing happened to me in industry ~ while working for years in/with industrial process control (written in BCPL), it was only after leaving environment did I discover a thing called a 'personal computer' existed...and I was going "DOS? What's that?"... true =)

So I had a spare esp32 laying around and some bits&pieces (I recall sending him the DAC later after he mentioned something that was exactly why a had a few DACs laying about =)....sort of just snailed the stuff to him with a 'hav phun' blessing ; I do recall an email discussion about vocoder use wrt voice treatments...Daleks, Cylons, the euro pop scene 'back then'...and {ahem} at the pinnacle of the covid crisis, comes communication of the covoder device being created....and I laughed...(covoder1900 would've been better imho =) Now here it is, IRL,...#respect... and later on down the track...(austpost tracking)...it'll turn up here ...where I'm likely to go grab one of the local goats to get live bleating as source material... I'll be sure to write a review, here, at that time =)

Incidentally.... blue bar orange found exactly where I left it...zero maintenance device 8)

[bodeplot]

Thanks for the kind words wotnot. This project would not have happened without you , and I would have discovered Arduino much much later on in life.

I really do like the Arduino architecture. It forces developers (particularly new developers) into thinking about concurrency from the very start. This is an important concept when developing applications on multitasking/context switching operating systems. I also like the system independence and portability of Arduino architecture. It gets around the issue of end of life, something always on my mind when maintaining hardware in the long run.