DaisySeedProjects: three open source guitar pedals and the software behind them

A pedal board of three, and why it is in a repository

The repository is the documentation of a specific physical object. The README describes it as a demo of a pedal board the author put together using three of their custom Daisy Seed based guitar pedals, and states that they designed and built the hardware and programmed the software, with the code, the PCB files and basic instructions on how to build the pedals all published on these pages.

That framing matters, because it tells you what kind of artifact this is. It is not a product line with a company behind it, and it is not a tutorial series. It is one person's hardware work, published in the form that lets someone else reproduce it.

The subject is the Electro-Smith Daisy Seed, a microcontroller platform that combines a processor, audio codecs and enough peripherals to run real time audio effects, and the README points to electro-smith.com for more information about it. The topic is unusual in open source terms, because the output is a physical object rather than a program, and that changes what a repository can and cannot do for you. A repository can give you the gerber files, the bill of materials and the firmware, but it cannot give you the soldered board, the potted enclosure, or the hours of assembly.

The project also has a demo video linked from the README, which is a reasonable way to see what the finished result looks and sounds like before deciding whether the hardware is worth reproducing.

The primary language is listed as C++, which reflects that the effect software is where the code volume is, and the licence is MIT, with the LICENSE file at the root of the repository. The tree is small and organised around the two halves of the work: a Hardware directory with one subdirectory per board design, a Software directory holding the effect platform, and a .gitmodules file alongside the .github directory and the standard Git housekeeping files.

One effect platform, several hardware targets

The software project is the more reusable half of the repository, and the README describes it as the software that can run on any of the custom Guitar Pedal hardware projects listed below as well as at the PedalPCB Terrarium hardware.

That sentence contains the actual engineering idea. The firmware is not written against one board. It is described as a flexible platform that abstracts the underlying Guitar Pedal hardware and allows a collection of Effects Modules to run on any of those hardware platforms.

So the structure is a hardware abstraction layer plus a set of effect modules that sit on top of it. The effects are what a user actually hears, and the abstraction is what lets the same effect code run on a 125b enclosure board with an OLED display and six knobs, on a 1590b board with four knobs and no display, and on a third party board the author did not design.

The Terrarium support is the interesting detail, because it changes the adoption question. A PedalPCB Terrarium is a commercially available open source pedal kit with its own published hardware, and if the effect software already targets it, then the question for someone who wants a working pedal is no longer whether they can build this author's board but whether they would rather buy a kit that is already made and flash the software. That is a materially different path from cloning the hardware, and it is a legitimate use of the repository.

The repository does not document the effect list in the top level README, so the modules themselves live in the Software directory. The structure of that directory, and the set of Effects Modules it contains, is where you look to find out what the pedals actually do.

The division of labour across the whole repository is therefore consistent: hardware directories hold the design and build documentation, and one software directory holds the code that all of them share.

Three boards, and the differences that matter

There are three hardware designs, and the differences between them are about assembly difficulty and physical size rather than about sound.

The first is a guitar effect pedal in a 125b enclosure with SMD parts. The README calls it a feature rich and flexible platform, and the specification is long: stereo audio, MIDI in and out, an OLED display, a rotary encoder for menu navigation, six knobs, two LEDs, two foot switches, and relay based true bypass switching, all built on the Daisy Seed microcontroller.

The second is a 1590b enclosure version with SMD parts, described as a compact platform. It keeps stereo audio and MIDI in and out, drops to four knobs, still has two LEDs, and offers one or two foot switches depending on the build. It keeps the relay based true bypass. The README explains the reason for the SMD choice: it is for easy manufacturing by a fab such as JLCPCB, so this is the version aimed at people who would rather have boards fabricated in volume than soldered by hand.

The third is the 1590b enclosure version with through-hole parts, described as having the same form factor and features as the SMD version of the 1590b pedal, minus the relay based true bypass switching, and using all through-hole parts for easy assembly at home with limited soldering skills.

That third design is the one to look at if you are the intended audience, because it trades a feature for buildability. The true bypass relay is what gives a pedal the switching behaviour guitarists expect, where the signal path is physically disconnected rather than switched inside the circuit, and on a digital pedal that relay is what routes the true analog input. Without it you get a different kind of switching behaviour, which the author has chosen to give up in exchange for a board you can solder with basic skills and a kit of parts you can assemble at home.

The two 1590b boards are not versions of one design either, they are separate PCB designs with separate documentation, and the README gives each its own ordering information page.

Ordering information, and the at-cost kits the author sometimes has

Each design links to its own ordering information document, for example OrderingHardware.md inside the docs directory of each hardware folder, and the README says that everything needed to build any of the pedals is provided along with fairly detailed documentation.

The contents of the repository for each design are consistent with that claim: a README for the design, a docs directory with the ordering information and photographs of the finished product and of the circuit board from both sides, and the PCB sources.

There is a paragraph in the README that explains an unusual aspect of the project. The author has been getting a lot of requests to buy kits or finished pedals based on the designs, says this is not something they typically do, and explains that sometimes they have extra PCBs, parts and enclosures lying around and are willing to pass them along at cost, with ordering details included alongside each design.

So there are two different things here and it is worth keeping them apart. The published artefacts, the PCB files, the ordering information and the documentation, are free and MIT licensed. The physical kits are an occasional, informal, at-cost arrangement that depends on spare parts existing at the time. Anyone planning a build should treat the spare-parts route as unreliable and budget for buying components from the distributors in the ordering information instead.

That distinction also frames what the repository is not. There is no assembly service, no enclosure machining service and no support contract. The design work is the contribution; the fabrication is on you.

The repository is a fork-friendly kind of project in practice even though the licence grants are simple: MIT means you may build the design, modify the PCB, sell what you make and sell the modifications themselves, without owing the author anything beyond keeping the notice.

Building one: the documentation is in the design folders

There are no build commands to run here, and it is worth saying why rather than inventing some. The artefacts here are source files for hardware, the gerbers and the bill of materials, plus C++ firmware that is compiled with the Daisy Seed toolchain, and the top level README does not document a single build or install step. Instead, each design links to its own README and its own docs directory, and the software project has its own README at Software/GuitarPedal/README.md.

So the practical sequence is: choose a design, read the README in that hardware directory, work through the ordering information document in its docs subdirectory to source the parts, and then build the board. The software side is read separately, from the Software/GuitarPedal README, where the Effects Modules and the hardware abstraction are described.

For anyone comparing the three designs before committing, the specification list in the top level README is the fastest way to narrow it down, and the deciding questions are physical. How large a pedal do you want, the 125b is the larger of the two formats and the 1590b is the smaller and more common stompbox size. How much assembly are you willing to do, because the SMD boards are meant to be fabricated and the through-hole board is meant to be soldered at home. Whether true bypass matters to you, since the through-hole version is the one that drops it. And how many controls you want on the faceplate, six knobs plus an encoder and a display against four knobs and two LEDs.

The MIDI in and out on all three designs is worth noting too, since it is what makes these more than a single effect box, and the OLED display on the 125b is what makes it feel like an instrument rather than a stompbox with a knob.

The Daisy Seed is the common denominator, and it is the one hard requirement. Every design here is built around that microcontroller, so the software and the hardware are not separable in a way that lets you swap in a different audio processor.

MIT, a slow version line, and a single designer

The licence is MIT, with the LICENSE file at the root of the repository. For hardware that you may build and sell, that is the permissive choice with no obligation beyond keeping the notice, and it applies to the design files, the documentation and the software alike.

The release history is modest. The recent tags are v1.6.1 from 2026-09-26, v1.6.0 from 2026-06-10 and v1.5.5 from 2026-05-16, and the last push to the repository was on 2026-10-10. The version numbers track the whole collection rather than a single component, so a tag means the state of the pedal designs and the effect software together, and there is no per-board release to pin.

The concentration of authorship is the defining characteristic. The README is written in the first person singular throughout, the hardware was designed and built by the author, and the software was programmed by the author. The only other credited party in the tree is PedalPCB, whose Terrarium hardware the software also supports.

That has a practical consequence. If you build one of these boards and find a mistake in the PCB, the fix is a change you make, and there is no maintainer to merge it into. If you want to change the effect modules, you are forking a project with one author, and the MIT licence makes that straightforward in the legal sense. The trade is that the designs are coherent because one person kept them coherent, and they are exposed to that person's time in the sense that nothing else is being maintained alongside them.

The projects directory naming also matters for anyone browsing the repository: the pedal designs are not products competing with each other, they are three points on a spectrum of size, assembly difficulty and feature set, sharing one effect software and one abstraction layer.

Editorial conclusion

Adopt this repository if you want to build a programmable DSP guitar pedal on the Electro-Smith Daisy Seed and prefer a design that someone else has already laid out and documented over starting from a blank board, since each design ships PCB files, a parts list and build notes. Do not adopt it if you need a finished pedal, a kit with a support contract or a design you can assemble without soldering, because the author states that selling finished pedals is not something they typically do, and the through-hole variant is the only one aimed at limited soldering skills. Verify first which enclosure size you want, because the 125b and 1590b versions are not variants of one board but separate designs with different footprints and different features, that the software you build expects a Daisy Seed, and that the effect modules in the Software directory match the hardware you are building, since the software is what abstracts the board underneath.

Frequently asked questions

Official sources

1. bkshepherd/DaisySeedProjects on GitHub
2. Issues
3. License: MIT
4. README
5. Releases