Build your own pedal controller.

[thofmann]

Hi,

I am currently working on the release 3.0 of my modular DIY pedal controller.
The topic was started some time ago on madbeans site http://www.madbeanpedals.com/forum/index.php?topic=8130.0
As to get more input and opinions to get things right I am expanding it into DIYStompboxes.

If you have not yet heard of this graet project  You might want to make yourself familiar with the current V2.0 build document: http://thcustom.com/?wpdmact=process&did=MS5ob3RsaW5r or follow the project on my site: http://thcustom.com/pedal-controller-diy/

I appreciate any input on he subject and would like to encourage everyone to participate. Please note that I currently do not sell any PCB until V2.1 and V3.0 are finally tested and approved.

Those are the questions at hand regarding the release of V3.0:

Manual switching
I found a way to add manual switching without canibalizing the TunerOut port. The solution is simple: Bank#0 will work as the manual switching stage.
After power on you are automatically in Bank#0 Thereyou can press the four keys 1-4 and use the shift key for directly accessing 5-8 like during programming. This allows direct toggle of everyindividual loop.
At any time you can use BANK +/- to retrieve the stored presets in BANK# 1-30. Also at any time go to BANK#0 and manually switch loops. As the loops do not change during BANK +/- this seems to be perfect.
I already veriefied this to be working nicely in a live environment.
Whats your opinion on it?

16 loops
I have an idea on how to switch between 16 loops. I am currently testing if the Shift key can toggle 4 layers of 4 loops each (ie lopp 1-4, loop5-8, loop9-12, loop 13-16) where the indicator LED would be off/on/flashing slowly/flashing fast)
Programming the LED to flash seems to be the hardest part in this
The 16 switch version (having 8 switches to program loops instead of only. 4) needs a prototype first before I can work on the programming.

MIDI
I would like your input on how the MIDI functions should be implemented.

Program change vs. Bank select.
The pedal controller has 32 banks a 4 presets which totals to 128 programs. The program change message would do that but using Bank select for the 30 banks and program change for preset 1-4 seems to make more sense. What do you think?

Manual switching
Retrieving stored presets is one part. The other part would be to switch each loop individually. How would you want to have this implemented? Would you switch each loop individually or wold you set the status of all loops at once? Any ideas on the midi messages Ou would use here?

Sysex
One important point would be to be able to import/export the whole memory settings for backup/restore/migration/copy to anotherpedal controller etc. This is simple but are there any preferences what should be taken into account?

Transfer of program change messages when keys are pressed.
One member suggested this to switch settings in other midi devices when a preset is changed.
This can be implemented simple by sending out a program change whenever a bank and preset is selected. Like sending program change 11 when BANK#3 preset #3 is selected  and program change 4 when BANK#1 preset#4 is selected. This would require to set a channel where this should be transmitted. Would you prefer a fixed channel or would you like to be able to choose one in a special settings area?

pre-assembled control and display unit
I am thinking about offering a pre-assembled display and control unit so people not wanting to tackle the digital part can still use the modular system to build their own pedal controller. You would be able to choose the color of the 7seg LEDs and the boards would have all parts already soldered and the boards mounted together. You only would have to solder and connect the relay and input modules.
Is this something you would be interested in?

I will appreciate all input and everyone can participate in creating something valuable for the DIY community which does not exist yet!

[Fredenando]

This is a great project. Probably I'll be a client for you. The 16 loops version can be my salvation... thank you!! 

[digi2t]

If I may make a recommendation;

If someone is interested in a MIDI controllable effect switcher, do a search for a 360 Systems AM-16 (NOT the AM-16/B with the ELCO plugs). It`s a 16 x 16 audio matrix switcher. I have three such units in my rack, and they are my salvation when it comes to loop creation and chain programming. You can program your effects in any order, save the loops and chains to memory, and recall them either manually, by footswitch, or via MIDI. They`ve been out of production for a while now, but I still see units crop up now and then. This is what it looks like;





1/4 inch jacks all around, all inputs and outputs are buffered, and even with really high gain pedals at insane volume levels, I`ve never experienced any crosstalk.

The nice thing about these units (for me anyway) is the matrix allows me to run the left and right channels of my stereo rig truely independant. I can run a fuzz on the right side, with a guitar synth on the left, etc. There`s not much limit to how a can arrange my loops or signal chains. I can even use it as a guitar switcher, keeping whatever guitars I need plugged in, and switching between inputs.

Shame they don`t make them anymore. Most I ever paid for one has been $200, least $90. Even at $200, I don`t believe I could ever DIY anything close to the capability and/or flexibilty that these beasties can provide. I`ve read that these units were heavily used by Rush in the late 90`s to organize and control their keyboards, samplers, and whatnot. I can see why. I know a lot of folks don`t know much about them, or have never heard of them even. I discovered them quite by accident. A happy accident.

So before you embark on a DIY mission to Troy, examine what your need really is, and if you can score one of these on the cheap. Just my two bits. 

[R.G.]

Just to toss in a bit of philosophy - 

There is a fundamental underlying link between flexibility and complexity. The more flexible something is, the harder it is to make it do anything in a coordinated manner. I think the discussion ahead of this bears that out.

Once you decide that it's no longer enough to turn effects on and off in a linear string, but instead have to rearrange them on the fly, it's clear that a nonblocking crossbar is what's needed; this gives any-to-any along multiple paths simultaneously, and seriously exceeds the ability of most people to use it well, even in a programming setup, as inside a computer. For onstage audio, you're back at setting things up carefully way ahead of time and hoping your programming of loops and paths doesn't get lost or erased.

That being said, there are a number of 8x8 crossbar switches for video and audio. I have a few of these kicking around. They work fine. I've even cased up the user controls into something that can run in a PIC. However, just the user interface needed to set this up gets big enough that it makes more sense to use something like a netbook to do the display of what's happening in real time. Blinky lights as we normally think of them can only tell you an effect's on, not what its predecessor and successors in the chain are, and even worse what happens when you hit that next programmed footswitch.

Even a banks/ranks/select/shift setup and a MIDI interface is a lot to expect a guitarist to use after the second beer of a set.

The electronics of this is pretty simple. Setting it up to be used live in real time is much more difficult. In the words of the Charlie Chan avatar Sidney Wang in "Murder by Death" - "Answer easy. Question... very hard."

[thofmann]

Thanks R.G.

Some philosophic discussion is always usefull when it comes to programmable equipment.
The pedal controller at hand follows an easy to use directive.
It will do the following things and this is priority sorted:

• possibility to program, store and retrieve up to 4 presets for a song (intro, rhythm, lead, outro)
• toggle each of the the effect loops manually for any freestyle needs during your gig
• use MIDI to utilize the above functionality in a controlled environment

According to a few people using the current version it does that quite well 
I am open to any ideas how to do the above things in a easy to use way. hence the cataloge of questions
The project will not extend to be anything else as a pedal controller. I do share RGs statement about complexity and I do think that anything beyond the defined scope should happen in a computer or -if it must be analog- as a studio overdub.

[digi2t]

R.G.`s wisdom rings true... as always.

Sidebar; My post wasn`t an attempt to highjack the thread. I was only presenting another option, one that some may not be aware of.

In my case, «complex» works, because that`s the way I like it. It`s always a question of need in the end. We`re just a two piece band, and for my part, it`s all about squeezing in as much texture as possible. I have a crapload of gear going at any one time, some running to MIDI clock, and the AM-16`s help me reign everything in to where I can control everything at the push of a footswitch on my MIDI controller.

Is it practical? For most musicians, probably not. Yes, it is a bitch to lug all that gear around, and yes, I do spend quite a bit amount of time programming gear for particular songs, sounds, etc. But, in the end, like most things in life, you reap what you sow. It works... for me.

In all reality, I find the concept of a DIY pedal controller absolutely marvelous. An idea whose time has been long overdue. Besides the relay board from Highly Liquid, which although being MIDI controllable is quite rudimentary, I don`t believe that I`ve seen anything this elegant. If you could encorporate MIDI, that would be great (my MIDI freak on the loose again! ). The three points that you plan on encorporating, will probably render a fantastic controller in the end. One that will meet the needs of many working musicians. And the fact that it`s DIY on top of that? Well... that puts the cherry on my sundae!

Now... can I build this on vero.... hmmmmm 

[thofmann]

Digit,

Ive seen your infiite project- so i am sure you can build a vero version
Do you happen to have some peference or a liking about the midi implementation i am planning?

[JohnForeman]

will controlling the pedal order be inside the scope?

[thofmann]

No,
The routing will be linear from loop#1-loop#8/16
There are a few controllers out there that offer 1 or 2 switches that can be configured for order change but this limitation did not seem to make much sense to me and the next step would be a switching matrix as mentioned a few posts before.

As this is a modular DIY system a module for switching the effects order can be derived out of the existing switchboards. If someone figures out how to do it - the controller would already be capable of controlling it.

[KMG]

I like TheGigrig ideology for linear routing.
http://www.thegigrig.com/acatalog/SWS_MIDI-14-1.html
They use dip switches to configure presets, configurations may be changed quickly without need of programming.
And you always see which loops assigned to presets.
My point of view on FX Switcher.


Control board.
http://milas.spb.ru/~kmg/files/projects/looper/Looper.pdf
One loop module, one of R6..R17 (only one installed) defines number of loop assigned to module.
http://milas.spb.ru/~kmg/files/projects/looper/OneLoop.pdf
DIP switch module, one of R2..R9 (only one installed) defines number of preset assigned to module.
http://milas.spb.ru/~kmg/files/projects/looper/PB.pdf
All boards connected together via 24 way flat cable (except signal wires).

[digi2t]

No,
The routing will be linear from loop#1-loop#8/16
There are a few controllers out there that offer 1 or 2 switches that can be configured for order change but this limitation did not seem to make much sense to me and the next step would be a switching matrix as mentioned a few posts before.

As this is a modular DIY system a module for switching the effects order can be derived out of the existing switchboards. If someone figures out how to do it - the controller would already be capable of controlling it.

That would be fine. Whether complex or simple, as R.G. pointed out, it's not feasable to be reordering on the fly. Even with my rig, I never reorder on the fly. The loops and chains are programmed beforehand, and I simply step through the order. If there is any reordering required, again, it's programmed beforehand.

If someone prefered to build this as a rack unit, then MIDI would be a great way to control it from the floor. I think something as simple as a Midi Mouse would be adequate, but a programmable foot controller would be my preference. I would prefer a linear number format for the banks and presets (1 - 128), and the have the foot controller programmed to call up the desired bank/patch from the pedal controller. That way one could build their "set list" starting at 1, and move up from there. I'm not a MIDI guru by any stretch fo the imagination, so I hope that makes sense.

Selectable MIDI channel would be desirable. Just in case someone wishes to intregrate this with an existing MIDI controller, this might avoid having to have another "stand-alone" system.

Individual loop switching is a tough call. I would be biased here and say "Yes!", but I'm a crazy mofo. You would have to run a deeper survey to see if it would be worth the effort. With 128 presets, many would feel that they have more than enough room, and global loop switching would be fine.

Sysex backup/transfer? YES PLEASE!!! Doesn't matter how you do it, just do it. I have ALL my gear that can dump sysex backed up. I have averted disaster on two occasions thanks to backups.

In the end, I don't envy you. As appealing as the K.I.S.S. principal may be (Keep It Simple Stupid), it's oh so hard to make everyone happy. 

[thofmann]

Thanks a lot digi2t.

The gigrig device seems to be very expensive for what it does. Especially using DIP switches for programming the loops is something I dropped the moment i saw it. There is another device offering this using 8 switches in a red encloseing. Forgot the name but that was the device i evaluated and due to the DIP programming as well as the heavy wiring required i dismissed this way of doing it completely.

The pedal controller can do the same. The workaround used for splitting the signal in the middle and routing it different ways can be used just the same - apart from the fact, that two-amp usage is already implemented in a different way without using an externaldevice.

The design of the gigrig looks ok, so its a matter of taste and money

[trixdropd]

Here's what I would like: Midi input and output. The midi input should accept program changes, plus cc#'s for the individual loops. I'd like to select preset 1, select which loops are active in that preset and hit store. The local stomps are just a bonus local controller.

[jubal81]

I'd like to see this stay simple - something that most people who can reliably build dirt boxes can put together.

[stirfoo]

That's awesome thofmann.

I've been working on an Atmel based looper for a while now. There aren't enough people working on DIY loopers, IMO. At least there aren't that many on this forum. Seems as though a few have come up with designs but you never see the final *working* board complete with schematics, BOM, and source code (not a hex file). I guess there's the lure of the capitalist pig. These things are god awful expensive. If you design a good one there's a chance you could make some money off it.

Speaking of money, as soon as I get enough spare cash to finish my looper I'm going to post it all here. I just hope it works as I intended and there is no way to know that until I get it on stage.

I do LED flashing in my program. There are no delays. It work off timers in the main loop. The Arduino has a millis() function that returns the milliseconds elapsed since boot. So for the LED flash I initially set ledClock = millis(); Then later in the loop I check if (millis() - ledClock > FLASH_WAIT_TIME) which is 250ms. If so, toggle the LED state, reset ledClock = millis(); and continue. Of course this is all in an if statement to test if I'm in Program mode.

I do something similar to flash the Bank 7 seg display when it's out of sync with the current preset.

I don't know PIC's at all else I'd give a bit more useful info.

[ECistheBest]

did u use LED drivers and/or shift registers for the output of the 7-seg displays? if you used PIC16F1826 did you have enough pins?

[bigtimp]

Thofmann,  great project.

To change programmes, my preference would be to go with PC (then my Glab gsc could control it)  I am considering a rack mount version to be used with a floor controller I alread have and I think (and could be off the mark here) that more floor controllers which will send PC commands but not that many that send Bank Select?

In terms of the manual operation of individual loops,  go with CC messages.

Also agree with others,  selectable midi channel would be vital and I like your idea of sending messages in response to pedal presses.