Old organ pedalboard - MIDI controller ideas

[jazzmonster]

Hi All,

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

[Rob_C]

Maybe this? PEDSCAN, Roman Sowa's micro standalone pedal controller.

"This little board is a scanner of up to 32 contacts, translating their closings into MIDI notes. In addition it can take one analog input, like potentiometer, to add one Continuous Controller like swell or volume. Typical application is MIDI controller for pedalboard in organ consoles, where it can take 32 keys and swell pedal."

Link ->Pedal Midi Controller

[jberentsson]

This one is nice and compact. Many other are almost 50% support structure vs keys.

[JanneI]

http://www.musicfromouterspace.com/anal ... edals.html

[bagoly]

Hi!


My name is robin, im from berlin and this is my first post here, though i’ve spent a lot of time reading and browsing the muffwiggler forum in the past, especially the great DIY section.

I am thinking about doing something very similar, only with a touch based Interface (see MPR121 for example, you can get it as a breakout module from Adafruit and it works very well) as a very compact, minimalistic controller for things like iPad apps, my modular or small hardware synths, as i try to keep my rig as small as possible.

I think i would omit option 2, as the whole usb-host thing seems to further complicate things, although i have not really looked into these things. A class compliant USB-MIDI-Device should be easily done with a Teensy out of the box, so there is no need for additional boards.

Also it gives you enough digital inputs so that you won’t have to mess around with additional circuitry like shift registers or key-matrices to read all the buttons. depending on which features you want to add, this could be a problem on the atmega328 (13 keys, 2 octave buttons and some LEDs will use up all the available pins on the 328).

Basically you could wire the whole thing up directly to the teensy and be ready to go and still have enough room for further features down the road. If you know your way around arduinos, writing code and programming on the teensy is essentially the same.

Also, i would definetely include the DIN-MIDI, as it is really easy to implement on your common microcontrollers and it adds a lot of options, especially if you deal with older hardware units.

Hope this helps!

robin

[jazzmonster]

Maybe this? PEDSCAN, Roman Sowa's micro standalone pedal controller.

"This little board is a scanner of up to 32 contacts, translating their closings into MIDI notes. In addition it can take one analog input, like potentiometer, to add one Continuous Controller like swell or volume. Typical application is MIDI controller for pedalboard in organ consoles, where it can take 32 keys and swell pedal."

Link ->Pedal Midi Controller

Thanks, I wasn't aware of this board. Fantastic idea with the expression pedal input (sending MIDI CC). Although I prefer building my own controller to have more flexibility regarding additional footswitches etc.

This one is nice and compact. Many other are almost 50% support structure vs keys.

Yes it is very compact (though a little on the heavy side). That's exactly why my friend kept it for years with the intention of turning it into a controller.

http://www.musicfromouterspace.com/anal ... edals.html

Interesting project. I think I made up my mind though about using a microcontroller - it will give me much greater flexibility and USB/MIDI/OSC connectivity. Also I'd like the keyboard to be polyphonic. On a real organ you sometimes press 2 (or even, though very rarely, 3) keys with your feet. With a microcontroller I can easily achieve that and add extra switches etc.

Hi!


My name is robin, im from berlin and this is my first post here, though i’ve spent a lot of time reading and browsing the muffwiggler forum in the past, especially the great DIY section.

I am thinking about doing something very similar, only with a touch based Interface (see MPR121 for example, you can get it as a breakout module from Adafruit and it works very well) as a very compact, minimalistic controller for things like iPad apps, my modular or small hardware synths, as i try to keep my rig as small as possible.

I think i would omit option 2, as the whole usb-host thing seems to further complicate things, although i have not really looked into these things. A class compliant USB-MIDI-Device should be easily done with a Teensy out of the box, so there is no need for additional boards.

Also it gives you enough digital inputs so that you won’t have to mess around with additional circuitry like shift registers or key-matrices to read all the buttons. depending on which features you want to add, this could be a problem on the atmega328 (13 keys, 2 octave buttons and some LEDs will use up all the available pins on the 328).

Basically you could wire the whole thing up directly to the teensy and be ready to go and still have enough room for further features down the road. If you know your way around arduinos, writing code and programming on the teensy is essentially the same.

Also, i would definetely include the DIN-MIDI, as it is really easy to implement on your common microcontrollers and it adds a lot of options, especially if you deal with older hardware units.

Hope this helps!

robin

That's a very insightful reply. I initially decided against teensy as it seems a bit of an overkill to use it for a matrix of 12 switches (+ some extra footswitches and LEDs).

The fact that it can become a USB midi compliant device very easily (with an extra DIN MIDI out) is very tempting though. I could also add OSC connectivity too if I wanted. I think it might be the way to go.

Thanks for all the replies, it is definitely a food for thought.