Microfoot (Advanced midi controller)

Silent Fly · Post by **Silent Fly** » 15 Jul 2008, 08:28

Micro-Foot (uF) is a MIDI foot controller designed to be entirely programmable.

I developed it using an Arduino board.

Apart from obvious constraints related to hardware and computational power of the CPU, there are no restrictions to the functionalities that can be implemented. uF can receive and send any MIDI message the developer wishes to implement.

I hope you will find it interesting.

Have fun!

Thanks to Soulsonic for reviewing the project documentation.

JiM · Post by **JiM** » 15 Jul 2008, 13:07

That's great !
I really like the idea of a DIY MIDI pedalboard, with great tweakabiliy.

For added flexibility of the interface, (ie more LEDs and switches), you may have a look at the "Chalieplexing" technique :
http://en.wikipedia.org/wiki/Charlieplexing
http://www.arduino.cc/cgi-bin/yabb2/YaB ... 1193402323
http://www.maxim-ic.com/appnotes.cfm/an_pk/1880
http://electronicdesign.com/Articles/In ... leID=18652
You could then drive 12 LEDs (or sense 12 switches) with only 4 pins, or use a 7-segment display ...

Just a comment on your licensing policy : you use CC-BY-SA, (which i also use) but add a Non-Commercial clause to it. There is another Creative Commons licence exactly for that : CC-BY-NC-SA http://creativecommons.org/licenses/by-nc-sa/2.0/uk/
May i also encourage you to release the source code, under an appropriate Free Software licence ?

Silent Fly · Post by **Silent Fly** » 15 Jul 2008, 13:26

JiM wrote:(...)
For added flexibility of the interface, (ie more LEDs and switches), you may have a look at the "Chalieplexing" technique:
http://en.wikipedia.org/wiki/Charlieplexing
http://www.arduino.cc/cgi-bin/yabb2/YaB ... 1193402323
http://www.maxim-ic.com/appnotes.cfm/an_pk/1880
http://electronicdesign.com/Articles/In ... leID=18652
You could then drive 12 LEDs (or sense 12 switches) with only 4 pins, or use a 7-segment display ...

Thanks JiM for the interesting links. I thought about using some multiplexing for the leds control but fortunately, I could do everything I wanted with the outputs I had available.

JiM wrote:Just a comment on your licensing policy : you use CC-BY-SA, (which i also use) but add a Non-Commercial clause to it. There is another Creative Commons licence exactly for that : CC-BY-NC-SA http://creativecommons.org/licenses/by-nc-sa/2.0/uk/

Thanks also for the info about the licensing. I will update the web site the next few days.

JiM wrote:May i also encourage you to release the source code, under an appropriate Free Software licence ?

Releasing the source code is my plans. I will do it in the (hopefully) near future. I need to clean it a bit and review some of the comments first.

JiM · Post by **JiM** » 15 Jul 2008, 19:30

I already imagine several variations of the µF with some knobs or another expression pedal, more (or less) footswitches, FX loops / amp channel control ... or even a full bass pedal keyboard !

Some bigger DIY projects around MIDI :
http://www.ucapps.de/
http://www.midibox.org/
and others arduino-based too :
http://little-scale.blogspot.com/2007/0 ... ample.html
http://www.diyblog.net/2007/12/19/diy-a ... -drum-kit/
http://www.embedds.com/be-a-guitar-hero ... ontroller/

It itches me for a while, i think it's time for me to get one of these : http://www.ladyada.net/make/boarduino/

Silent Fly · Post by **Silent Fly** » 15 Jul 2008, 20:09

JiM wrote:

I already imagine several variations of the µF with some knobs or another expression pedal, more (or less) footswitches, FX loops / amp channel control ... or even a full bass pedal keyboard !

Some bigger DIY projects around MIDI :
http://www.ucapps.de/
http://www.midibox.org/
and others arduino-based too :
http://little-scale.blogspot.com/2007/0 ... ample.html
http://www.diyblog.net/2007/12/19/diy-a ... -drum-kit/
http://www.embedds.com/be-a-guitar-hero ... ontroller/

It itches me for a while, i think it's time for me to get one of these : http://www.ladyada.net/make/boarduino/

One interesting application would be a midi stopbox controller. The unit would open/close true-bypass switches for pedals connected to a rack-mounted pedaboard. True-bypass could be implemented with optocoupling devices like in the BAJA Silent Selector

µF (or any other midi foot controller) could control the midi stopbox controller via MIDI messages.

Cow4prez · Post by **Cow4prez** » 22 Jul 2008, 21:01

doesn't sound like it does control change midi which is what you need for a stomp box type switching...

Silent Fly · Post by **Silent Fly** » 23 Jul 2008, 09:30

Cow4prez wrote:doesn't sound like it does control change midi which is what you need for a stomp box type switching...

Micro-Foot can send and receive any possible MIDI message (sys-ex included). It only needs to be programmed - like any other midi foot controller. My current implementation sends CC messages when it detects variations on the expression pedal position.

The midi stopbox controller that I mentioned in my post above wouldn't need CC messages. It could use Program Change messages.

On the midi stopbox controller, you just need one button for every pedal. If for instance you want to turn on pedals 1 and 3 then it receives PC001, simply press button 1 and 3. When any button is pressed, the unit goes in "learning mode" and start detecting midi messages. The first midi message it receives it is associated with pedals 1-3. It is not different from the "learn" function of a lot of software packages. You also need an extra button for "no pedals" of course.

The midi stopbox controller could also be easily integrated in a multi-fx rack. Any message that it is not addressed to the midi stopbox controller can be forwarded to other midi units that are daisy chained. This would allow the control of other units with just one foot controller.

It theory, it doesn’t even need midi cables. Arduino can use external Bluetooth adapters. It should be quite easy to implement a midi-over-Bluetooth connection between micro-foot and the midi stopbox controller.

jessej · Post by **jessej** » 06 Aug 2009, 11:42

This is really cool!

I have an Arduino duemilanove and have been looking for some projects worthwhile..

I've got this controller previously bookmarked:

Four 4051 multiplexers controlled by arduino to scan 32 voltage dividers and output as midi.

Here's an expression pedal via arduino:
http://www.codeproject.com/KB/system/MI ... ct=3130307

If one wants to go totally nuts, there's the new Arduino Mega that has 16 analog ins...

I'm not much of a coder, but I think someone could make a really killer looper with puredata that would use an Arduino footcontroller.
http://en.wikipedia.org/wiki/Pure_Data