Open-Source Hardware Explained: Examples and How to Get Started

Open-source hardware is any physical device whose design files are published under a licence that lets anyone study, build, modify, sell and share it. In practice that means the schematics, circuit-board layouts, 3D models, bills of materials and firmware are all made public, the same way the source code of open-source software is. This guide explains what that actually involves, how the licensing works, which projects prove the model, and how to start building with open hardware in New Zealand.

What is open-source hardware?

Open-source hardware (often shortened to OSHW) is a physical thing — a circuit board, a sensor, a robot, a 3D printer, a keyboard, even a server — released with enough documentation that someone else could reproduce or improve it without permission. The term covers the object itself and, crucially, the design files behind it.

The widely accepted definition is maintained by the Open Source Hardware Association (OSHWA). Under that definition, the design must be shared in a format that can be modified, anyone must be free to make and sell the hardware (including commercially), and there must be no restriction on who can use it or in what field. A product can be “open” even if some off-the-shelf components inside it, such as a microchip, are not — provided those parts have publicly available datasheets.

That last point matters, because “open-source hardware” is not the same as “free hardware.” You almost always pay for the physical board, the parts and the manufacturing. What is free is the design — the knowledge of how to make it — and the legal right to do so.

How does open-source hardware work?

Open-source hardware works through three things: published design files, an open licence, and (optionally) formal certification. Each answers a different question for the person reusing the design.

The design files

A genuinely open project publishes the information you would need to rebuild it from scratch. For an electronics project that usually means:

• Schematics — the circuit diagram showing how components connect.
• PCB layout files — the printed-circuit-board design, in an editable format (for example KiCad or Eagle files), so a factory can fabricate the board.
• Bill of materials (BOM) — the full parts list with values and part numbers.
• Mechanical files — CAD models or STL files for any case or 3D-printed parts.
• Firmware and software — the code that runs on the device, released under its own open licence.

Publishing a PDF of a finished circuit is not enough on its own; the files have to be in a form other people can actually edit and manufacture from.

The licence

Hardware designs are usually released under a licence that spells out how they can be reused. Common choices are the Creative Commons Attribution-ShareAlike licence (CC BY-SA), which lets anyone copy, modify and sell a design as long as they credit the original and release their changes under the same terms, and dedicated hardware licences such as the CERN Open Hardware Licence. Arduino, for example, publishes its board schematics and CAD files under CC BY-SA while releasing its software tools under GPL and LGPL licences. The firmware and the physical design are often licensed separately.

OSHWA certification

Because “open source” is a claim that is easy to make and hard to verify, OSHWA runs a free self-certification programme. Launched in October 2016, it lets a creator register a product, confirm it meets the open-source hardware definition, and display a certification mark with a unique ID (for example “US000001”). Certification is voluntary, so plenty of legitimately open projects never apply — but a certified mark is a quick way to know a design really is open rather than just marketed that way.

Open-source hardware vs open-source software

Open-source hardware borrows its philosophy from open-source software, but the economics are different. Copying software costs almost nothing: you download a file. Copying hardware still means buying components, paying a factory and shipping a physical object, so “free to copy” never means “free to own.”

The two also overlap constantly. An open hardware board is far more useful with open firmware and open tools around it, and many projects pair the two — an open 3D-printer design that runs open firmware, or an open sensor feeding an open-source home-automation platform. If you are weighing up the software side of the equation, our guides to running your own home server with Proxmox and open-source alternatives to Microsoft Office show how the same open model plays out in software.

Examples of open-source hardware

The projects below are the ones most people point to when they explain open-source hardware. They range from a single microcontroller board to entire data-centre server designs. The table compares them so you can see what “open” actually means in each case.

Arduino

Arduino is the project that popularised open-source hardware. It is a family of small microcontroller boards (the Uno is the classic) plus a free programming environment, and its board designs are published under an open Creative Commons licence. Because the designs are open, dozens of compatible “Arduino-compatible” boards exist from other makers — which is exactly what the licence intends. Arduino is the usual starting point for electronics beginners because the hardware is cheap, the community is huge and the code is approachable.

BeagleBoard (BeagleBone)

The BeagleBoard family, including the BeagleBone Black, is one of the most thoroughly open single-board computers available: the board design files, bill of materials and documentation are all published. That makes it a favourite for industrial and educational projects where being able to inspect and modify the hardware matters.

RepRap

RepRap is an open-source 3D-printer project with an unusual goal: a machine that can print many of its own parts. Its designs, released under free licences, seeded the entire desktop 3D-printing industry — most affordable hobbyist printers trace their lineage back to RepRap, directly or indirectly.

ESP32 (Espressif)

The ESP32 is a low-cost microcontroller with built-in Wi-Fi and Bluetooth. The chip itself is a commercial Espressif product rather than an open design, but the development tools are open, reference board designs are published, and the hardware is extremely well documented, so it behaves like an open platform in practice. It is the workhorse behind countless DIY smart-home gadgets — including the local ESP32 hack that adds Wi-Fi control to a Mitsubishi heat pump.

Open Compute Project

At the opposite end of the scale, the Open Compute Project (OCP) applies open-source principles to data-centre hardware. Launched publicly by Facebook (now Meta) in April 2011, it publishes designs for servers, storage and racks so that large operators can build cheaper, more efficient infrastructure. It shows that open hardware is not only a hobbyist idea — it runs at industrial scale.

RISC-V

RISC-V is an open instruction set architecture — essentially an open specification for how a processor understands commands. Anyone can design a chip around it without paying licence fees, which is why it has become a major open-silicon movement. It is a useful reminder that “open hardware” reaches all the way down to the design of processors themselves.

Is the Raspberry Pi open-source hardware?

Not strictly, and this is a common misconception worth correcting. The Raspberry Pi is often listed alongside Arduino as an open-source hardware example, but it does not meet the open-source hardware definition. The Pi’s main processor is a proprietary Broadcom system-on-chip, and the Foundation does not release the board’s full design files under an open licence. Much of the software around it is open, and its documentation is excellent, so it is very much part of the open-friendly ecosystem — but it is not itself open hardware in the way Arduino or BeagleBone are.

None of this makes the Pi less useful. It is still the easiest route into tinkering, and we cover it in depth in our guides to what a Raspberry Pi can do and choosing between Arduino, ESP32 and Raspberry Pi. It just belongs in the “open-friendly” column rather than the “open hardware” one.

What can you build with open-source hardware?

Open-source hardware covers almost any project where you want to understand, control or customise a device rather than accept a sealed black box. Common uses include:

• Home automation and sensors — temperature, humidity, power and door sensors that feed an open platform like Home Assistant, keeping your data local instead of in a vendor’s cloud.
• Energy monitoring — DIY meters built on open boards, as covered in our guide to home energy monitoring in NZ.
• Robotics and makerspace projects — motor controllers, robot chassis and educational kits.
• 3D printing and fabrication — printers, laser cutters and CNC machines descended from open designs.
• Test and lab gear — open-source oscilloscopes, logic analysers and bench tools.
• Repairable consumer devices — keyboards, handheld games and laptops designed to be opened, upgraded and fixed.

How to get started with open-source hardware in New Zealand

Start small, with a cheap board and a clear first project, before you buy anything expensive. A realistic path looks like this:

1. Pick a platform for your goal. Choose an Arduino or ESP32 for simple electronics and sensors; a single-board computer if you need a full operating system. Our board comparison walks through which suits which job.
2. Buy a starter kit. A kit bundles the board with breadboard, jumper wires, LEDs, resistors and sensors so you are not ordering parts one at a time. In New Zealand you can buy boards and kits from local electronics and maker retailers online, or import from the official Arduino and Espressif stores; prices for a basic Arduino-compatible starter kit typically run from roughly NZ$40 to NZ$120.
3. Install the free tools. The Arduino IDE and the ESP32 toolchain are free downloads. Everything you need to write and upload code is open-source.
4. Follow one project end to end. Blink an LED, then read a sensor, then put a reading online. Finishing a small project teaches more than reading ten tutorials.
5. Lean on the community. Official documentation, project forums and local makerspaces are where open hardware really pays off — someone has almost always solved your problem and published the answer.

Benefits of open-source hardware

The appeal of open-source hardware comes down to control, cost and longevity.

• Cost savings. There are no design-licensing fees, and open designs face real price competition from multiple manufacturers, which pushes hardware prices down.
• Customisation. Because you have the design files, you can change a board to fit your exact need instead of working around a fixed product.
• Transparency. You can see exactly how a device works — valuable for security review, education and trust.
• Longevity and repairability. If a company stops supporting a product, open files let the community keep it alive, repair it and make spare parts.
• Collaboration. Improvements made by one person can be shared back, so designs get better over time.

The trade-offs and common mistakes

Open-source hardware is not automatically cheaper, safer or easier, and a few misunderstandings trip people up.

• Assuming “open” means “free.” You still pay for components, boards and your own time. Open refers to the design, not the price tag.
• Treating every “open” label as genuine. Some products call themselves open but publish only a PDF schematic, not editable files. Check for a real, modifiable design release — or an OSHWA certification ID.
• Confusing open hardware with open software. A board can be open while its firmware is closed, or vice versa. Read both licences.
• Expecting polished support. Community support is excellent for popular projects and thin for obscure ones. There is rarely a help desk to call.
• Ignoring compliance and safety. Anything that plugs into mains power, transmits radio or is sold commercially may need electrical safety or radio-compliance approval — being open does not exempt it from the rules.
• Buying the biggest board first. Over-buying is common; most first projects run happily on a NZ$15 microcontroller.

Who is open-source hardware for?

Open-source hardware suits anyone who wants to learn, build or keep control of their devices rather than accept a closed product. Students and educators use it because the designs are teaching material in their own right. Hobbyists and makers use it because it is cheap and endlessly customisable. Small businesses use it to avoid vendor lock-in and licensing fees, and to keep sensitive data in-house — a theme we return to in our guide to self-hosted software for small businesses. If you only want a sealed gadget that works out of the box and never changes, closed commercial hardware may suit you better — open hardware rewards people who want to look inside.

Vanliga frågor (FAQ)

Is open-source hardware free?

No. The design is free to use, copy and modify, but you still pay for the physical board, the components and the manufacturing. “Open” refers to the openly published design and the legal right to reuse it, not to the cost of owning the object.

Is open-source hardware legal to sell?

Yes. A core part of the open-source hardware definition is that anyone can make and sell the hardware, including for profit, without asking permission. The licence usually requires you to credit the original design and, for share-alike licences, to release your own modifications under the same terms.

Is the Raspberry Pi open-source hardware?

Not strictly. The Raspberry Pi uses a proprietary Broadcom chip and its full board design files are not released under an open licence, so it does not meet the open-source hardware definition. Much of its software is open and it is widely used in the open community, but Arduino and BeagleBone are better examples of genuinely open boards.

What is the difference between open-source hardware and open-source software?

Open-source software is code you can freely view, change and share, and copying it costs almost nothing. Open-source hardware applies the same openness to physical designs, but reproducing it means buying parts and manufacturing, so it is never free to own. The two are often combined in a single project.

How do I know a product really is open-source hardware?

Look for editable design files — schematics, PCB layouts and a bill of materials you can actually modify — released under a recognised open licence such as CC BY-SA or a CERN Open Hardware Licence. An OSHWA certification mark with a unique ID is the quickest confirmation that a design has been checked against the open-source hardware definition.