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Background and Prototypes

A project log for Fluxamasynth Modules

The Fluxamasynth is a module that makes it easy to add high quality MIDI sound to any Arduino or Raspberry Pi project.

FluxlyFluxly 10/01/2018 at 21:270 Comments

The very first Fluxamasynth was part of my final project for the Fab Academy back in 2010. Fab Academy is a 20 week "distributed education" class built on the Fab Lab network, based on Neil Gershenfeld's "How to Make Almost Anything" class. Each week culminates in a final project that integrates as many digital fabrication techniques as possible. 

I wanted to make a pinball machine with the theme MZO, based on the unfinished opera that Dylan Thomas and Stravinsky were to write. In the final weeks I triaged that idea down to a few pinball machine functional modules: some LED arrays, a flipper, and the music module. 

While researching possibilities for a programable music module I came across the SAM2195 chip from Dream Sound Synthesis (then part of Atmel). It was a $4 chip that would be the heart of a simple keyboard or Karaoke machine. I ordered a half dozen, drew up a schematic and board and sent away for some PCBs.

One of the problems for me at the time was that the IC package was a very fine pitch QFN40. At our Fab Lab I had met Paul Badger who teaches at RISD and had a business making inexpensive Arduino kits. Paul would come in to the Lab and make solder stencils on the laser cutter and I would bend his ear for electronics tips.

I showed the QFN parts to Paul and he said "sure, you can solder that by hand!" I spent along time (and a lot of flux) trying to get the QFN chip on the board with my standard issue Weller soldering iron. After at least two hours of fiddling I heard the first sound come from the Fluxamasynth Arduino shield: an RTTL version of Ravel's Bolero!

Paul and I worked together for a few years and I made another iteration of the Fluxamasynth with an Atmega on board. For some reason at the time I was still thinking it would be a kit (and we were still working out of a toaster oven for our SMT modules), so it still had some through hole components on board.

I used the same schematic for both boards, but for some reason the second iteration wouldn't work no matter how much rework I put in. It turns out there was a reset pin I was supposed to pull high that I had missed in the first version. By a lucky break in the way that the first board was laid out, the floating pin somehow coupled with one of the power pins and everything worked. If that hadn't happened I may not have ever gotten the first board to work, writing it off to my hand soldering technique.

Until 2018 the definitive version of the Fluxamasynth has been the third iteration, the Fluxmasynth Arduino Shield. It's still kind of a niche module but has been used in a bunch of installations and by a number of instrument makers such as Ed Potokar.

One of Ed Potokar's instruments, on the right.

This year I tightened up the board design and made three new variations, one for the ESP32, the Raspberry Pi and in the Adafruit Feather form factor.  

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