I am building a MIDI footswitch unit (Not my first) to use with my Dwarf setup.
If interested, you can follow my progress here
S’manth x
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always love to see these DIY midi controllers.
You’d also check out GitHub - alf45tar/PedalinoMini: Wireless and Bluetooth MIDI Foot Controller.
Which I use and is a good starting point if you don’t want to start from scratch.
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I did a build of that ["They also build that do not work with wood" - Trampa: Self build MIDI footswitch. - Build Diaries - Basschat] [I made one · Issue #342 · alf45tar/PedalinoMini · GitHub] , it is an awesome system!]
It uses ESP, which does not have builtin USB-MIDI, and when I used it it did not have multiple button presses; also it only support a single OLED display.
And so I am building Trampa from a greenfield to address these issues.
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ok - that’s cool! I think I saw that and modeled my case like yours. Got distracted in the middle of it and not finished it yet. Crazy small world 
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Can’t wait to see what you come up with!
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the whole case is 3D printed. I’ll often have the top seperate. Its easier to change something and prints are faster as you don’t have to reprint everything again.
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I am interested since I am thinking to do something similar, thanks for sharing. I have some question about your project:
What are you going to display on the LCD screen?
Could be useful to have a led blinking with the midi clock?
Have you checked out the “control surface” library before going into low level programming?
Using a chocolate midi i am unsatisfied about the “sampling rate” of the expression pedal, do you think it is a midi limit or an implementation issue?
Thank you in advance
Z
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@Zavorra , my answers ibelow.
What are you going to display on the LCD screen?
A number of things.
What the button will do, for example
- Distort
- Record
- Snapshot One (I am going to find a single character icon to represent SnapShot, perhaps a camera ala HX Stomp)
If the text is too long to fit in the 128x32 pixel display (at a good readable size from the floor) it will scroll.
If a switch is a on/off “toggle” type, then I will indicate on/off status; a box around the display or intervert the text or flash the text, I’m going to try these to see which works (and perhaps support all of these as user configuration)
Could be useful to have a led blinking with the midi clock?
Good idea, I have considered adding another OLED display between footswitch 2 & 3 to display general device info (such as WiFi connected, bank name) and I could use this to show MIDI clock.
Have you checked out the “control surface” library before going into low level programming?
I did. I was not confident that I could configure the inputs and displays in the way I wanted and it uses polling, whereas I intend to use interrupts (fired when buttons are pressed or the expression pedal is adjusted) and both pico cores to maximise performance; important as with my plan to include a web server for configuration. As I mentioned above, I’ve previously built a MIDI controller using the amazing PedalinoMini codebase and its rich featureset has shaped some of my approach.
Using a chocolate midi i am unsatisfied about the “sampling rate” of the expression pedal, do you think it is a midi limit or an implementation issue?
I would say, given that there are many expression to MIDI devices out there as well as the innumerable twisty knobs and glide pads that it is more likely a chocolate implementation thing, I’ve been able to read my expression pedal and send MIDI from it already (at a nice responsive rate). The code does automatic calibration of the min/max values. At present it is very sensitive to ‘noise’ so I see a few too many sequences like CC 65, CC 64, CC 65, CC 66, CC 65 when the pedal is not being changed (I only send a MIDI if the ADC value changes, but it flickers a little). I have seen some denoising code for ADC reads that I am going to check out as well as perhaps having some Only send a message if the MIDI value changes by more than X logic.
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the next “Chapter” is the saga …
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I hope you’ll be posting code to github or the like, because I would love to see how you’re multiplexing the MIDI and serial debug messages. Also, congrats on getting it working. I’d have done a happy dance as well 
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I am most certainly going to publish it on github (code and circuit diagrams) once I’ve got a reliable MVP working version
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Hi everyone,
not to brag about it, but a long time ago, I contributed a bit of code for MOD which allows any joystick/game-controller to be used as a MIDI controller. Buttons trigger notes and other continuous controls trigger CC messages. The idea behind it was to evicerate a cheap game controller and use its electronics as a brain for a DIY foot controller but soldering switches to the board proved too tedious for my impatient self.
Also I think it would be possibly better to trigger CC messages as well with the buttons rather than notes, but ideally, one would want this to be configurable via a file.
Still, if you have a joystick or game controller lying around, you can give it a go. It should still work I hope (is it still part of the software running on the Dwarf @falkTX ?)
Maybe allowing a regular PC keyboard to control CC messages could be an idea too…
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I’ve used a midi keyboard quite successfully to send CC messages to the Dwarf, but the ability to trigger midi using a foot operated device is a must have for me …
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Of course. My point was indeed to gut the cheap electronics of PC keyboards, or game-controllers to use them as the brain of a DIY foot controler.
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New version of Pedalino supports midi clock sync and tap tempo now…just a fyi
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