// I also posted this to muffwigler forum (https://www.muffwiggler.com/forum/viewtopic.php?p=2357805#2357805) but I figured you might have some interesting ideas too. //
I was given this organ pedal board. It comes from an old Italian electric organ (I don't know which model, not that it matters). Friend of mine kept it for years as it seems to be very good quality. It is rather heavy but it has a handle and it is not too big. I haven't looked inside of it yet (won't get a chance until next week).
As I studied church organ, I can actually play this thing (which is not that hard anyway). So I figured I can turn it into a controller for use with my modular and/or as a MIDI device. I have a concert coming up for the modular synth + grand piano and I think it would be quite cool to also play the pedals.
I know how to convert it into a controller but would like to see if you have any ideas/potential problems I might be missing.
I consider the following options:
1 - Turn it into a class compliant MIDI device (not a USB host), for use with a computer or a tablet. Each of the 12 keys would send a midi note on/off message. I think it would be useful to add a button to transpose the keyboard through all the available octaves (button seems more robust than a pot that could be knocked by accident).
2 - As above, but add a USB host port too (so I can plugin a USB synth or a CVPal converter directly to the controller).
3 - As 1 & 2, but also add a traditional DIN MIDI out. I have Barton MIDI2GATE module in my eurorack, if my pedalboard had a MIDI out I could use it to trigger envelopes and other events in my synth.
All of the above seems quite simple to do using atmega328 chip (same as arduino pro mini or nano).
I would completely bypass the existing circuit in the pedal (and the great looking connector). I might need to replace the switches (depending on what shape they're in).
The device would be powered from USB (with a LED indicator). The current octave transpose setting would be stored in EEPROM so it wouldn't be lost on power off.
For USB host option I'd probably use a ready made Hobbytronic USB host device (http://www.hobbytronics.co.uk/usb-host-board-v2) as it would save me coding the USB to MIDI part of things. Are you aware of any other solutions?
I do realise I'd need to fiddle with debouncing the switches in pedals - both in hardware and software.
The transpose button would have to be a rather large one, guitar pedal style (for use with foot).
Which one of the above options makes most sense? I think probably all 3 of them, but correct me if I'm missing anything.
As I'm planning to use an atmega chip (or arduino) with loads of digital and analog pins available I also thought about further extensions of this project, as there is a lot of space on the panel and hopefully inside.
Below are some ideas I have:
4 - Add a couple of footswitches to the top part of the silver panel, and have them generate MIDI CV control each (value 0 or 127 for on or off) - exactly like some of the usb footswitch controlles available online. That would be handy for enabling stuff in pure data patches on my tablet. That could be set up in software to latching/non-latching (mode changed if held for more than 5 sec.)
I could also add a circuit and jack output for the above footswitches to generate 0 - 5V or close an external circuit.
5 - Add a good quality USB hub inside for plugging more than 1 controller to the tablet.
Some more silly ideas:
6 - Some sort of array of lights (LEDs or lasers or something else) that would change colours on pedal key press - could be good for live performances.
7 - CV/GATE out - this one probably doesn't make sense and it would be quite complicated to get it right (with temperature compensation etc.) and besides I have 2 CVpals anyway so USB is way easier (and only 1 lead).
8 - Internal VCO/Filter/VCA for playing bass lines (probably way too much work for what it's worth).
For the moment I will probably settle just on options 1 & 2 (possibly 3) as I am eager to use it.
What do you think? Is there anything else that could potentially be handy to have in my pedal board?
Looking forward to hearing your opinions! Thanks