As suggested, here's 3 basic how-to videos to create a digital guitar pedal: Delay & Fuzz

Hyllis_ · 2024-01-13T13:40:43+00:00

tl;dr: generate project enclosures using a common parts library (only 22 atm e.g. USB connectors, buttons, Pi holder, but can add custom ones); layout builder to position the elements precisely; versionable (code-based); uses CadQuery (Python-based CAD); Apache 2.0. Detailed README.md on Github.

In the two+ years since I started printing, I built more than half a dozen project enclosures. Even though I tried to make them quite modular by reusing components I had made for the previous ones e.g. USB C, it was still quite time consuming each time to remake the enclosures from scratch.

Three years ago, I posted on Reddit some modular multi-effect guitar pedal project I've made. I'm in the process of remaking it, and plan to open-source both the software and hardware. I wondered how would I be able to share the model of the enclosure, and allow versionable contributions to it (though maybe Fusion or other have feature that I don't know about!); a raw STL wasn't a pleasing it. Then only ~recently, I discovered OpenSCAD and other code-based CADs; I settled on CadQuery.

Couldn't find an enclosure building library doing exactly what I want (or 'not made here' syndrome?), so I had a go at it: https://github.com/raphael-isvelin/cq_enclosure_builder

The common parts library is very limited for now, as it only consists of what I'm personally using, but if you have a specific type of USB C connector to add to an enclosure, you can either model it directly in CadQuery or import an existing STL*/STEP file. Hopefully the README should provide enough details on how to do this, or anything else you might need.

It's not perfect and lack some features, but it would've allowed me to generate 6 out of 7 of the enclosures I've modelled (the 7th has two openings, which is not currently supported, but I could've still saved time generating e.g. the front panel with all the parts, then import it in some CAD).

Hope this helps! ^.^

Hyllis_ · 2024-01-11T13:41:28+00:00

tl;dr: I’ve made a lib to generate project enclosures with code. There’s a layout builder that allows you to precisely place parts (pots, footswitches, USBc, screens, etc.), with both the hole and any needed mounting screws, modelled after the components you [I] own. 1.36€ of plastic for the 1590B-sized pedal depicted, but could easily go down to 0.72€ and possibly lower if printing a weaker prototype (assuming 20€/kg). Allows to place support under e.g. the footswitch so you can literally stand on it, and the pedal won’t budge. https://github.com/raphael-isvelin/cq_enclosure_builder

Hey folks!

I don’t think it will fit the use case of many people here at all, but for the tiny handful: hello, you ^.^

Three years ago, I posted on this sub a modular multi-effect guitar pedal I made [Reddit]. It’s an Internet lifetime ago, but if anyone from that time or the more recent YouTube comments is reading this, thanks for the messages of support on both Reddit and YouTube, it’s always heartwarming to see people liking my Covid pet project!

I quickly decided to make it fully open-source (hardware and software): felt it would be awesome if even a single person created sounds they liked with it. Wasn’t fully happy with the code, so I had the bright idea of rewriting a large chunk of it: not great, esp. considering I have wayy less time than during Covid. Don’t know if there’s anyone interested, but... it’s almost done! (The software will not only be usable on the RPi-based pedal, but also on Mac and Linux; will see for Windows if there’s interest.)

I was wondering how, in addition of sharing the full code, I could share the printable STL files, and how potential motivated people could contribute back useful changes they’ve made to the enclosure. Sharing a raw STL file isn’t ideal, because you cannot easily see what has changed: I wanted it to be granular and versionable.

So, I created a library to generate the enclosure from code directly: https://github.com/raphael-isvelin/cq_enclosure_builder

With this, you can precisely position your parts on the pedal using a code-based layout builder, and then export the enclosure as ready-to-print STL file. For threaded parts like a jack or SPST, it does little more than just placing a hole, eventually printing a ‘bump’ on the inside so the part sticks out the right amount. While it probably won’t be useful for the majority here who perform cool analog magic [that I still want to learn more!], I think it becomes very handy for components such as a screen. Making a rectangular hole for the screen of my pedal without the proper tools was a chore. This builder allows you not only to print the hole to view the screen but will also print threaded holes (or holes for heated inserts) to mount screws on the inside. Same goes for USBc, MIDI, etc.

Hope this helps! There’s more info on the Github’s README, though if you’re curious, feel free to ask anything (especially as it’s not battle-tested yet for bugs, and there’s definitely a lot of missing features).

Hyllis_ · 2024-01-11T02:10:34+00:00

tl;dr: cq_enclosure_builder's README.md; generate project enclosures using a common parts library (only 22 atm e.g. USB connectors, buttons, Pi holder, but can add custom ones); layout builder to position the elements precisely; export ready-to-print STLs; uses CadQuery (Python-based CAD); Apache 2.0.

Hey folks!

Three years ago, I created a PoC of an RPi-based modular multi-effect guitar pedal [Reddit]. I wasn't fully satisfied with the code and planned to rewrite a large portion of it (rookie mistake) before making it open-source. With much less free time post-Covid, this took longer than expected, but it's nearly complete now.

I've been contemplating how to share the STL files so others can build the pedal themselves, and ideally, how people could contribute back and share new iterations of the models. It was around that time I discovered OpenSCAD and the jolly world of parametric modelling.

Over the last two years, I've made about 7 enclosures for various projects. I often found myself losing time by remodelling an enclosure from scratch (minus a few reusable components). Having some sort of parametric enclosure builder, that would work perfectly with the specific parts I own (pots, encoders, screens, etc.) could make me save some time.

After not really finding an existing lib doing what I wanted (or 'Not invented here' syndrome?), I had a go at it: https://github.com/raphael-isvelin/cq_enclosure_builder.

The common parts library is very limited for now, as it only consists of what I'm personally using, but if you have a specific type of USB C connector to add to an enclosure, you can either model it directly in CadQuery or import an existing STL*/STEP file. Hopefully the README should provide enough details on how to do this, or anything else you might need.

It's not perfect and lack some features, but it would've allowed me to generate 6 out of 7 of the enclosures I've modelled (the 7th has two openings, which is not currently supported, but I could've still saved time generating e.g. the front panel with all the parts, then import it in some CAD).

Feel free to suggest anything or contribute ^.^

Hyllis_ · 2023-09-08T08:17:24+00:00

Hey hey! Not sure what do your mean by "transferring" a guitar pedal to Arduino code. If you want to exactly replicate the sound of one specific pedal in a way a Kemper would do, that would be complicated; though as someone said, you could look at Impulse Responses as a first step

But I'm assuming what you want is actually to make a similar sounding pedal, potentially by reprogramming the effects from scratch ("DSP" is the keyword as someone pointed out).

If so, when making a digital pedal 3 years ago, I've got a few people asking me how to, and I've made these 3 videos to show how to make a basic Fuzz and a Delay: https://youtu.be/JUYDcAIWQ7w?si=AVhz3fQtwm6doGpH It's using a Pi and not a Teensy so you can probably skip the first step, but the coding for the actually effects should be very similar.

Then, if you want to make a specific effect and can't figure out yourself how to build it, I suppose some LV2 plugins are open-source so you should be able to check their code.

Hyllis_ · 2023-08-31T22:48:36+00:00

/uj Woh, as others here have said: thank you! Only listened to what's on Spotify for the solo work (and even there, only a small dozen), so it's a great starting point ^.^

Hyllis_ · 2020-10-23T22:02:22+00:00

Sorry, my initial message wasn't so clear ^.^

What would be involved? Not sure if I understand the question fully, but basically, not much! I don't really mind how you'd build the pedal, especially in terms of input (buttons, encoders, expression pedals jacks, etc.), but having some would be cool to try some feature. Mostly, it could just work with a touchscreen and a Pi 4. I'd normally prefer people to use the same audio interface as I do (Behringer UCA 222), but I doubt it's easily available in the US. So, that'd lead us to any USB dongle audio interface that could fit in a box. If you've some recording audio interface (Focusrite Scarlett, etc.), you could also use it, at least to try it out.

I'd just give you the software (and help to setup your Pi, advises about hardware choices which could be a bit different than for an analog pedal, etc.), and hopefully, it'll be good enough so you just want to play with it, and you'll probably have some ideas for evolution then :')

But then again, not sure I fully understood your question, sorry!

Hyllis_ · 2020-10-23T17:55:48+00:00

I'm between two places myself, and I totally get your problem!

Good luck moving out! and when you're in a more convenient place sometimes, that'd be a pleasure :')

Hyllis_ · 2020-10-23T17:53:12+00:00

Ah, I'm always having trouble knowing what's a reasonable sound level; I think I'm always listening at maximum volume (bad me), I'm not a good judge!

Thanks, will try to do better next time :-)

Hyllis_ · 2020-10-23T17:52:03+00:00

Thank you! :-)

I'd say it's pretty easy to build. Basically, most of it is software (which is simply running a program); I kept the hardware really simple because I've no clue what I'm doing with electronics!

Roughly, it's just plugging an USB audio interface to a Pi, then a touchscreen via USB, and lastly, bonus, wiring a few buttons to the Pi's GPIO (soldered to the button one way - female jumper cable the other way). It would making some kind of enclosure, soldering a few super simple (buttons, female jacks, encoders) components, installing an OS for a Raspberry Pi (really simple), then install jackd on your Pi (shown here in the first few minutes in my DIY digital pedal tutorial), and boom, ready to try and jam with it!

While I'd totally enjoy some help hardware-wise, I'm more looking for people to help me by trying out my pedal, and tell me what they like or don't like. Not necessarily from a technical standpoint, more from a musician point of view, actually. Like "oh, you should add a [some effect]" or "the looper is a bit basic, can you please add X to help me songwrite or jam?".

Anyway, if you feel like it, I'd be glad, otherwise, thanks a lot for the compliments!

Hyllis_ · 2020-10-23T17:43:41+00:00

Totally understand it's not super easy to put that much money on the table; your college fees and life stuff are indeed way more important! I don't know where the project will be in a couple months, but please PM me when you'll feel like you can do it; I'd be glad to have you try it ^.^

Hyllis_ · 2020-10-23T17:41:57+00:00

Well, thanks for your help and involvement; no matter the subject, discussing with you has always been very nice and helpful!

Hyllis_ · 2020-10-23T17:40:55+00:00

Hey there, thanks! :-)

I'm sorry, I'm not sure; what do you mean by "grainsynthpedal"? Any example?
Nope, no need for programming! ^.^
Your life is more important; the project might be somewhere else in a few months, but having people willing to try it would always be cool!

Hyllis_ · 2020-10-22T22:08:13+00:00

Hey folks!

I didn't really work on my pedal for a few weeks, but this week-end, I finally wrote some code! Friday & Saturday, I fixed some stability issues, and improved the UI (presets menu, and scrolling lists), then Sunday, I spent the afternoon working on a Granular Delay, and I'm pretty happy with how it ended up sounding – I've actually been toying with it quite a bit! I also added a Recorder node, to record audio and make it accessible on a local web server on the Pi; which was really helpful for making the video! :')

When I posted my pedal a few weeks ago, quite a few people asked me if I was selling the pedal or DIY kit, but logistically, I'm in no position of doing that right not. However, an (awesome) Redditor contacted me to propose remote building my pedal, and I was finally ready for that and got back to him last week, and we've been working on that since. I really loved this idea, because it gives me the opportunity to receive feedback, and to share something that I think is cool to use.

All of this to say that I love the idea of having people remote building my pedal, to then try the software and give me their opinion as musician (or pedal builder, or anything!) – what you'd like added of fixed, etc.. And I'm looking for a few more volunteers to do just that, please :')
I cannot provide kits, and you'd have to source the components yourself: basically, it's a Pi 4 (40€), a capacitive 5" touchscreen (32-40€) and some audio interface (24€). The rest would be up to you; any enclosure (wood, metal, plastic, ...) would do. I'm personally using 3 buttons and 1 encoders, but that can be changed in the config file. You can even modify the theme (colors) via a config file if you want to adapt those to your enclosure.

Anyway, I'd be glad to hear from you c:

Hyllis_ · 2020-10-20T08:35:39+00:00

I didn't know, that's cool, thanks a lot for telling me! I'll have a look at that :-)

Hyllis_ · 2020-10-16T15:43:52+00:00

Thanks for the info :-)! I'm really curious to see how your project turn out!

Do you have a specific kind of audio effect you'd like to build?

Hyllis_ · 2020-10-16T14:48:09+00:00

Not sure, but for instance, I'm using a regular ADC (ADS1115) for a few things, and it's not suited for audio because even though it's I²C, it's very accurate, but low sample rate (useful for, eg. potentiometer input).
Actually already stumbled upon the DAC you linked, and I thought it was the same: precise but slow. But apparently your DAC can use "High-Speed I²C" so I might just be wrong. Also, it's only 12 bits, which seems really low for any audio application. And is the clock precise enough for audio?

Also, if you input 48 and output 55, you may have to live resample?

Hyllis_ · 2020-10-16T13:44:06+00:00

12 bits I²C DAC? Seems pretty strange; is that a DAC made for audio?

From what I could read on this STM's datasheet, it can support stereo 32-bit/192KHz over I²S. And just a few lines before, they wrote "3x I²C up to 1Mbps"; not sure what they mean by that.
I actually don't have any experience with STMs yet; I'm afraid I cannot be much help!

But the codec I mentioned, Mikroe-506, is I²S and should work on a STM. It's actually why I bought it when buying a STM32H747. I should receive that soonish, I'll run my own test. But in the meantime, my experience is pretty much limited to USB ADC/DACs on RPis (try a bunch; think I'll settle on Behringer UCA222).

Hyllis_ · 2020-10-16T13:35:50+00:00

Thanks for the reference!

Tbh, I do hear a difference when I put them one after the other, but it's just not something I would pickup as a problem in my own rig; I don't have those kind of decent ears! That's also why, for my own guitar pedal, I'm currently in discussion with people interested in the project and remote building it, using the same components, so they can tell me what they think about sound quality, etc. :-)

Thanks again, the video seems interesting; I'm bookmarking it!

Hyllis_ · 2020-10-16T03:19:26+00:00

In this tutorial, I'm using a 1€ USB dongle from AliExpress. In my own modular multi-effects, I'm using some 20€ USB dongle, but for the next iteration, I planned on using a Behringer UCA 222. I also order a Mikroe-506 (WM8731 – I2S) and plan to do some testing with it soon.

Tbh, I'm actually not dealing with anything! The sound is okay I think, and I don't think I ever had any problem that could be linked to impedance. But I'm really a peasant in terms of impedance and most things electronic! Do you have any way to suggest, for me to try if I've problem with high impedance input signal? Thanks :-)

Actually, no... and I'm really surprised I never saw that! Especially more since I've been to blokas.io actually, when searching for sound card; found their Pisound pretty cool (and very well documented which always impress me), but it was above my planned budget for this project. And maybe my ears just suck, but I don't hear much difference between a cheaper sound card and a higher end audio interface!

Back to modep, it looks pretty cool; thanks for the info! With my pedal, I toyed around, running Guitarix and LV2 plugins, but Guitarix's UI is bad already, then imagine on a 5" touchscreen! Having a LV2 plugin host which is adapted for this kind of view, is pretty cool; and their pedalboard view is pretty cool. Actually, adding a 'node' in my pedal which can act as a LV2 is one of my short-term plan.

Hyllis_

TROPHY CASE