Chromatic button style midi controller

[BlueCamoose]

Howdy folks, I have built a couple (v1 and v2) synths that use the C system chromatic button accordion layout and the Teensy (arduino) audio library.
The sounds are not great, and I am working on interfacing with analog synths via midi right now. I have a couple people contact me via hackaday or facebook that were interested in getting one, but am not really set up for anything beyond prototyping.

Anyways I am looking at doing a third revision, that will focus less on the digital audio and be more of a midi controller. I would love to find some other folks that would be interested in collaborating on the specs and maybe gauge what the interest would be in doing a product run.
I want to tailor this to folks that are using multiple monophonic analog synths to create polyphonic sounds, but instead of relying on the poly-chain implementation of the synth manufacturer the controller would individually address the different analog synths using different MIDI channels. This means that there could be switches on the controller so that all of the features (latch, pitch-bend, volume change) could be configured to send to all of the synths or just the synth that got the last note. Think doing pitch bends on a single note. The controller would either round-robin the notes to different synths or could be set up to send the same notes to multiple synths at the same time.

My specs so far are:
1) 6-row / 3 octave (72) button keyboard. Would be software configurable for any layout including C system and bayan. Note with these layouts every note would be playable two places on the keyboard which comes into play with how I want to do MIDI addressing.
2) TRS or 5-PIN MIDI port out, with extensive routing options how the notes get sent to different MIDI channels
3) 2-axis Joystick for note bends and volume changes. The scale would be software-configurable.
4) Octave range buttons
5) latch function (suppress NOTE-OFF messages).
6) Cherry MX style mechanical keys



My question is who would be interested in this? What would be the price point for a kit? assembled unit? Anyone have CAD skills that could modify the drawings for my PCB and/or chassis that would want to collaborate? I can do the coding...

I not looking to get rich, everything I have done so far I released the code open source. But there are costs for me.

 

[tcabot]

Yes, I've built a 5-row CBA with an 8-row moschino bass end.
I could load any chord bass or freebass config, to try them out, which was great.
Keyboard chassis was 3d printed for cherry style keys.
Air pressure sensor, Roland-style, just more sensitive.
Accordion was a midi controller running on teensy, which played into a raspberry-pi synth.

Had grand plans for it, but got it playable, played for a while, then gave up on further development.
Some things that nearly made me cry:
- Very hard to find decent sounding samples. Yuck! To add insult to injury, there's half a dozen different standards for samples, with no conversion options.
- MIDI over USB standard is not standard...That is, every dang processor interprets midi over USB differently. What a load of bollocks. This makes it near impossible to code a universal controller that's packed with features - in my experience you have to pair the controller to a specific processor.
- More sensitive pressure sensor is not great - if you play fortissimo, it temporarily shifts its zero and very noticeably upsets push/pull balance. A less sensitive sensor gives you a rubbish Roland-like bellows curve options.
- Bass end keyboard had to be made in two levels, which takes about 3 hrs to strip & assemble back is there's an issue with a button sticking.
- Problems finding a reliable battery power source for an all-onboard config.

More importantly, I've moved away from CBA for a variety of reasons.

It was not a complete waste of time - I've stripped the box and I'm re-building it into a much smaller and simpler silent practice melodeon that I can bash while the kids are sleeping.
I got my money back for the Roland because I no longer needed it for silent practice.
I've realised how much I like a good acoustic instrument. A midi accordion is a bit like a digital girlfriend . A real one's a lot better.
I got to play Moschino, loved it, and was eternally grateful that I did not waste thousands on some converter bayan monstrosity.

You're on the right path, but the whole world is against you, if you're looking for a digital accordion perfection.
Good luck!

 

[JerryPH]

Dang you two are amazing to be able to do something like this!!

 

[utterances]

This sounds very cool, I’d love to have a sturdy small 3-4 octave 4 row c system synth keyboard for the pocket-ability.

I ve done some basic modeling /CAD and 3d printing banjo bridges but nothing this big yet…

 

[BlueCamoose]

Yes, I've built a 5-row CBA with an 8-row moschino bass end.
I could load any chord bass or freebass config, to try them out, which was great.
Keyboard chassis was 3d printed for cherry style keys.
Air pressure sensor, Roland-style, just more sensitive.
Accordion was a midi controller running on teensy, which played into a raspberry-pi synth.

Had grand plans for it, but got it playable, played for a while, then gave up on further development.
Some things that nearly made me cry:
- Very hard to find decent sounding samples. Yuck! To add insult to injury, there's half a dozen different standards for samples, with no conversion options.
- MIDI over USB standard is not standard...That is, every dang processor interprets midi over USB differently. What a load of bollocks. This makes it near impossible to code a universal controller that's packed with features - in my experience you have to pair the controller to a specific processor.
- More sensitive pressure sensor is not great - if you play fortissimo, it temporarily shifts its zero and very noticeably upsets push/pull balance. A less sensitive sensor gives you a rubbish Roland-like bellows curve options.
- Bass end keyboard had to be made in two levels, which takes about 3 hrs to strip & assemble back is there's an issue with a button sticking.
- Problems finding a reliable battery power source for an all-onboard config.

More importantly, I've moved away from CBA for a variety of reasons.

It was not a complete waste of time - I've stripped the box and I'm re-building it into a much smaller and simpler silent practice melodeon that I can bash while the kids are sleeping.
I got my money back for the Roland because I no longer needed it for silent practice.
I've realised how much I like a good acoustic instrument. A midi accordion is a bit like a digital girlfriend . A real one's a lot better.
I got to play Moschino, loved it, and was eternally grateful that I did not waste thousands on some converter bayan monstrosity.

You're on the right path, but the whole world is against you, if you're looking for a digital accordion perfection.

Nice project!
I think the big difference about what I am going for is that I am not trying to make it sound like an accordion. If I want something to sound like an accordion I will play an accordion It is more about making electronic music and having the benefits of an isomorphic keyboard. Currently I have been feeding it into different analog synths with varying degrees of success.

 

[utterances]

@BlueCamoose reading your post made me do some cursory search, I wonder if it's easier to hijack parts and technic people are already using for mechanical keyboards? e.g. this one looks almost like the right layout geometry but maybe not the right key cap shape:

Look, a nice round candy-colored mechanical keyboard | TechCrunch

Who likes gadgets? You do! Here's a nice one. It's a cute wireless keyboard with round, friendly buttons and a shiny, happy look to it. It has no agenda but to be pretty and useful. Everything is fine.

techcrunch.com

combined with free software like https://sourceforge.net/projects/vmpk/ it can already do chromatic layout. just need the same chassis being extended longer for more octaves.

 

[utterances]

Actually just stumbled on this kit from Japan, similar to what you are planning?

GitHub - 3araht/giabalanai: Build guides for giabalanai chromatic accordion MIDI keyboard with no bellows.

Build guides for giabalanai chromatic accordion MIDI keyboard with no bellows. - 3araht/giabalanai

github.com

 

[BlueCamoose]

Actually just stumbled on this kit from Japan, similar to what you are planning?

GitHub - 3araht/giabalanai: Build guides for giabalanai chromatic accordion MIDI keyboard with no bellows.

Build guides for giabalanai chromatic accordion MIDI keyboard with no bellows. - 3araht/giabalanai

github.com

yes, that is very similar to what I built. Down to the round keycaps.