organ console : 384 IN / 128 OUT

[Astazou]

Hello all,

New to the forum and to the MIDIbox concept. New to electronics also.

Pretty scared by the DIY side of the things, but I need to take the plunge :D

It's nearly 2 years now that I have an old Dr Böhm 3 keyboard / pedalboard organ console which needs to be converted to MIDI. The old electronics were unusable and were removed some months ago, so I only have the contacts.

The title says everything : it will boil down to about 384 contact inputs (3x61 keyboards, 32 pedalboard, 68 stop switches and around 30 pushbuttons for presets). Later I might want to add LED feedback, and get rid of the computer screen, so less than 128 LED outputs.

And I was forgetting : I have one swell pedal (pot) and space in the console for another one, so I'll use some analog inputs for that.

I imagine that with this number of contacts, the obvious setting should be 10 DINs, probably 3 or 4 DOUTS so 3 COREs if I use the PIC version.

The obvious firmware should be MIDI128.

I didn't find either on uCapps nor in the forum nor the WIKI if the STM CORE is able to control more than 4 DINS. Does it ?

Does MIDIO128 run on MIOS32 or do I have to program my own application if I use the STM ?

Are there compelling reasons to use the STM instead of the PIC (except: the STM is newer & more powerful) ?

Thank you

Edited November 23, 2009 by Astazou

[nILS]

Hello all

Welcome aboard Astazou :D

Pretty scared by the DIY side of the things, but I need to take the plunge :D

That's the spirit! :yes:

I imagine that with this number of contacts, the obvious setting should be 10 DINs, probably 3 or 4 DOUTS so 3 COREs if I use the PIC version.

You can always wire the "buttons" in a matrix which will allow you to use more than the original 128. A 16x16 matrix would allow for 256 buttons for instance. A forum search for "button matrix" or "blm" might get you some useful hints.

The obvious firmware should be MIDI128.

Being a programmer I tend to think that the obvious firmware choice is to write an app yourself :)

I didn't find either on uCapps nor in the forum nor the WIKI if the STM CORE is able to control more than 4 DINS. Does it ?

If I am not mistaken it (will?) support(s) a max of 8 DINx4 modules.

Does MIDIO128 run on MIOS32 or do I have to program my own application if I use the STM ?

The pic version does not. You'll either have to wait for a new one to appear or code it yourself - which gives you the highest flexibility anyways :)

Are there compelling reasons to use the STM instead of the PIC (except: the STM is newer & more powerful)?

Yes and no. If you don't need the powerful CPU I'd still go with the PIC. It's smaller, easily replaced if you break sth, a bit cheaper and still powerful enough for most apps. I guess the USB port of the core32 does count as a major advantage, if you need/want USB :)

[clem!]

Hi Astazou,

New to the forum and to the MIDIbox concept. New to electronics also.

Pretty scared by the DIY side of the things, but I need to take the plunge :D

...

...it will boil down to about 384 contact inputs (3x61 keyboards, 32 pedalboard, 68 stop switches and around 30 pushbuttons for presets). Later I might want to add LED feedback, and get rid of the computer screen, so less than 128 LED outputs.

And I was forgetting : I have one swell pedal (pot) and space in the console for another one, so I'll use some analog inputs for that.

for a starter project this seems to be a very big project. I would recommend to split this into 3 or 4 smaller projects!

I imagine that with this number of contacts, the obvious setting should be 10 DINs, probably 3 or 4 DOUTS so 3 COREs if I use the PIC version.

The obvious firmware should be MIDI128.

I think that midifying an electronic-organ was not the main intention of MIDIO128 but to midify mechanical-musical-instruments! So if you are able to programm your own firmware you should use (as nILS told above) a matrix to scan the manuals. Eventually as the first project and then expand it with MIDIBOX64(E) as controlsurface.

Best regards,

clem!

Edited November 25, 2009 by clem!

[Astazou]

Yes, it is a big project. Alas, church organ playing involves in these modern times at least 2 keyboards + pedalboard when you intend to play some serious music. So I guess this is the minimum project size. The 3rd keyboard, the stop switches and the preset buttons can come later.

About contact spreading, I'm stuck with a common bus wire for all key contacts, and the wire can **structurally** NOT be cut every 8th key if I want to use a diode matrix. I've spent enough time on this topic for the last 2 years to be pretty sure I have no choice except designing a new keyboard switch system. No way ! :)

I'm fully aware that MIDIO128 is a bit overkill, anyway, it's the simplest thing which will enable me to get started quickly, especially because all the organ intelligence will be in the software module (think Hauptwerk or jOrgan) in the computer, so basically I need only contacts to MIDI and a bit of MIDI to LEDs (later :)) No need of direct USB link to the computer, I already own a 1x1 USB/MIDI cable, and that shoumd be enough