RISC-V & open cores
An instruction set anyone may implement without a licence. Open cores such as CORE-V and the open toolchains around them mean a design can outlive the company that fabricated it.
Open hardware · Open firmware · Open formats
Build the gear you can actually repair.
Polymathes OÜ is a multidisciplinary practice — technology, research, communication and digital innovation — that publishes its engineering in the open. Schematics, firmware notes and field-tested guides for people who wire, solder, code and calibrate their own infrastructure, across networking, audio engineering and computer graphics. All under open licences, all reproducible with parts you can still buy next year.
3Engineering tracks
100%Reproducible designs
CC BY-SADocumentation licence
0Vendor lock-in required
The three tracks
One workshop, three disciplines that keep colliding
A networked audio interface is a networking problem, a sound problem and a graphics problem at the same time. We treat them that way instead of shipping three silos.
Track 01
Networking
OpenWrt routers, WireGuard meshes, BGP with FRR or BIRD, CAKE for bufferbloat, AES67 audio over IP — and a patch panel you can trace with your eyes closed.
Track 02Audio
Gain staging, impulse-response capture, PipeWire and JACK graphs, LV2 and Faust DSP, networked audio over open protocols, plus measurement instead of marketing.
Track 03Graphics
The Mesa stack, Vulkan and GLSL, linear colour workflows with OpenColorIO, Blender and Krita pipelines, and GPU compute that stays portable.
Our definition
“Open” is a checklist, not a vibe
Hardware is only open if someone else can rebuild it from your files without asking you a single question. We hold every published design to the same five tests.
- Schematics and layout are published in an editable format — KiCad, not a flattened PDF.
- The bill of materials is orderable from at least two distributors, with second sources named.
- Firmware builds from source with a pinned toolchain and a one-command build.
- Interfaces are documented — registers, pinouts, protocols and voltage levels, not just pictures.
- Failures are published too — erratas, respins and the mistake that caused them.
What we are not
We are not a store, a Kickstarter and not a certification body. Nothing here is a finished consumer product, and nothing here is safety-certified. Mains-voltage work, radio transmission and laser equipment are regulated in most countries — check your local rules before you energise anything.
How to contribute
Write-ups are plain HTML and Markdown in a git repository. Open an issue with a measurement, a correction or a build photo, and it gets reviewed in public like everything else.
Open hardware · Open source
Every layer open, from silicon to session file
Open source gives you the right to read, change and redistribute code. Open hardware goes further and asks for the design files themselves — schematics, layout and the bill of materials — so the object can be rebuilt, not merely reflashed. We work across both, and we say which is which instead of blurring them together.
Arduino, BeagleBone, Pi
Boards with published pinouts, mainline kernel support and a real community. For control surfaces, sensors and measurement rigs, a documented header beats a proprietary module every time.
KiCad, ngspice, OpenSCAD
Your schematic is a text-and-file project you can diff, review and reopen in ten years. Never publish a design in a format only one vendor's tool can read.
coreboot, U-Boot, OpenWrt
Boot firmware you can audit and replace is the difference between owning a device and renting it. OpenWrt runs the network; coreboot and OpenBMC run the machines.
| Layer | Open example | Typical licence | What it buys you |
|---|---|---|---|
| Instruction set | RISC-V, OpenHW CORE-V | Open specification, permissive cores | Nobody can revoke the architecture under you |
| Board design | Arduino, BeagleBone, Olimex, Pine64 | CERN-OHL-S, OSHW where declared | You can respin the PCB when a part goes end-of-life |
| EDA & simulation | KiCad, ngspice, OpenSCAD, FreeCAD | GPL, LGPL | Your own files stay openable without a subscription |
| Boot & management | coreboot, U-Boot, OpenBMC | GPL-2.0 | Recovery without a vendor tool or a service contract |
| Operating system | Linux, OpenWrt, Zephyr, FreeRTOS | GPL, MIT, Apache-2.0 | A patched, auditable system you can rebuild from source |
| Audio | PipeWire, JACK, Ardour, LV2, Faust, SoX | LGPL, GPL, MIT | Sessions and plugin chains survive a vendor exit |
| Graphics | Mesa, Wayland, Blender, Krita, Godot | MIT, GPL, Apache-2.0 | Drivers and content tools you are allowed to fix |
| Datacentre | Open Compute Project designs | OCP specifications, OSHW | Rack hardware without proprietary management lock-in |
Open source is not automatically open hardware
A project can ship excellent GPL firmware for a board whose schematic is secret. We label each release separately, and we refuse to call a design open when the layout is missing — because a binary blob you can flash is still a black box you cannot repair.
Licences we use, and why
Documentation under CC BY-SA 4.0, code under GPL-3.0-or-later, hardware under CERN-OHL-S v2. Each one keeps derivatives open, which is the point: improvements to a shared bench should return to the bench.
Reference builds
Three starting points
Each one is a weekend project with a documented bill of materials and a measurement step.
Quiet network closet
A fanless OpenWrt router, a managed switch, a PoE budget and a UPS that actually reports its state. Includes the cable-label scheme and the backup policy.
Measurement-first audio chain
Interface, calibrated microphone and free software: loopback latency, noise floor and frequency response measured before a single plugin is loaded.
Colour-managed Linux workstation
Wayland, a calibrated display profile, an OpenColorIO config and a render farm of one. Verifiable end to end with a test chart and a colourimeter.
Where to begin
Pick the track that matches your bench
| Track | First project | Tools you need | Page |
|---|---|---|---|
| Networking | Flash a supported router, segment your LAN | Router, serial header, patience | Networking → |
| Audio | Measure your room and your loopback latency | Interface, measurement mic, tripod | Audio → |
| Graphics | Calibrate a display and profile it | Colourimeter, supported GPU | Graphics → |
| All three | Build the networked studio: one clock, one ground, one backup | Everything above | About us → |
Stay in the loop
Corrections are the highest form of praise
If a measurement in one of our guides does not reproduce on your bench, that is a bug in the documentation. Send the numbers — we publish the diff.