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Defining Open Hardware
October 18, 2023 This article was contributed by Koen Vervloesem ChatGPT translation https://lwn.net/Articles/945870/
Open hardware (or open hardware) refers to hardware developed in a manner similar to open source software. There is a widely accepted definition of open hardware, but it may not be as well-known as open source software. Additionally, there is a popular certification program for hardware manufacturers to indicate which standards their devices meet. However, some vendors show more motivation to participate than others.
The primary advocacy organization for open hardware is the Open Source Hardware Association (OSHWA). Established in 2012, it provides a definition of open hardware maintained by open initiative organizations. The OSHWA definition describes its main principles as follows:
Open source hardware (OSHW) refers to tangible artifacts, including machines, devices, or other physical objects, whose designs are publicly shared in a way that allows anyone to manufacture, modify, distribute, and use these objects.
This principle is implemented through 12 criteria, which differ somewhat from the ten standards in the definition of open source.
OSHWA recommends eight types of open hardware licenses in its FAQs. These licenses are divided into two categories: strong copyleft licenses, which require derivative works to be released under the same license, and permissive licenses, which allow proprietary derivatives. The recommended strong copyleft licenses include the non-hardware specific GPL and Creative Commons Attribution-ShareAlike (CC-BY-SA), as well as hardware-specific CERN Open Hardware License and TAPR Open Hardware License. The recommended permissive licenses include, but are not limited to, the FreeBSD license, MIT license, and Creative Commons Attribution (CC-BY), along with hardware-specific Solderpad Hardware License.
It is important to note that, like open source software, licenses that prohibit commercial use are incompatible with the OSHWA definition. Since creating hardware inevitably involves funding, it is challenging to use hardware designs without commercial activity.
OSHWA has also established a set of best practices for creators of open hardware projects to reference. For example, these best practices recommend sharing the original source files you will use to modify the hardware design. While the best practices encourage the use of free open source software to design hardware, they acknowledge the reality of needing to use proprietary programs and file formats in this field, thus allowing proprietary solutions.
If we only discuss printed circuit boards (PCBs), such as microcontroller boards and single-board computers, the content that needs to be shared includes mechanical drawings, electronic schematics, bills of materials, and designs for PCB layouts. If any of these components are missing, the hardware product cannot be replicated.
A notable example is the Raspberry Pi single-board computer, whose information is incomplete. Although electronic schematics have been released, they primarily show the pin layout of the connectors. These simplified schematics are useful for users or those who want to design additional boards, but they are not suitable for someone wanting to create their unique Raspberry Pi. According to the licensing information, the schematics use the Attribution-NoDerivatives 4.0 International (CC BY-ND) license, which is not an open hardware license as it does not allow derivative works.
Self-Certification Program
In 2016, OSHWA established a certification program that relies on creators voluntarily self-certifying their projects. This allows them to use relevant logos to indicate their compliance with the OSHWA definition.
OSHWA has the authority to revoke certifications and has indeed done so in some cases. The first instance was in 2018 when the certification of the Motedis XYZ 3D Printer was revoked because the project documentation link was no longer valid. After OSHWA could not obtain a copy of the documentation from the contact in the certification application, the certification was revoked. For the same reason, the organization also revoked the certification of the Atmel SAM D10C Breakout Board made by San Antonio Technologies.
In 2022, OSHWA began revoking hardware certifications based on documentation status. This is because OSHWA has long considered documentation as part of the certification process. When documentation can no longer be found on the manufacturer’s website, OSHWA will publish that documentation as part of the certification revocation process.
Earlier this year, OSHWA revoked the certification of the SparkFun DataLogger IoT – 9DoF. This was due to SparkFun “accidentally submitting the certification.” Although the hardware of the project is open source, the firmware is not. This surprised users, as SparkFun is considered a staunch supporter of open hardware. SparkFun CTO Kirk Benell explained in a GitHub issue: “The OSHWA logo/certification was a mistake in our system when we built [sic] that board – everything was running automatically and not checked before release.”
The list of certified open hardware projects on the OSHWA website includes over 2500 projects. These projects cover various devices, including Arduino boards, add-on boards for Arduino and Raspberry Pi, drone flight controllers, 3D printers, smart speakers like the Mycroft Mark 1, and even electric vehicle charging stations. Adafruit has nearly 700 certified products, while SparkFun has nearly 600, holding significant positions on the list. Many of these certifications are for Arduino-compatible boards. Smaller participants like Olimex have 68 certified products, including ESP32 boards running mainline Linux and its OLinuXino series single-board computers.
Each product page on the certification website provides a direct link to the product documentation. However, hardware and software files cannot be accessed directly. To find hardware schematics, you need to visit the referenced project website and search for the relevant files on that page. For example, for Adafruit products, the hardware schematics are linked under the technical details title, while for SparkFun products, they are shown under the documentation tab. Olimex shows the link to the hardware schematics under the hardware title.
In a blog post about the first revocation of certification, OSHWA explained that it seeks to reduce redundant work and therefore does not host hardware documentation on its site:
Developing and maintaining a fully functional documentation hosting solution is not OSHWA’s core competency. There are already many good solutions for developing and maintaining software and documentation online. Requiring certifiers to update and maintain another documentation repository to receive certification is considered an unnecessary burden.
Finding Open Hardware Elsewhere
There are also other places to find open hardware that may not necessarily follow the OSHWA certification program. For example, OpenHardware.io contains over 500 projects. For each project, the page displays the license, photos, descriptions, bills of materials for ordering parts, source code related to software, and all necessary design files for the hardware. The site hosts projects including sensor boards, relays, LED controllers, remote controls, add-on boards for Arduino and Raspberry Pi, adapters, and more. However, many projects are still marked as “in progress.”
Kitspace hosts some interesting electronic designs, though on a smaller scale. Notable products include a micro Arm microcontroller board suitable for USB ports, a micro Arduino-compatible board, a WiFi air pollution sensor board, and boards for ESP8266 and ESP32 microcontrollers. The site is sponsored by several PCB manufacturers, providing direct links to manufacturers from product pages.
However, open hardware is not necessarily limited to electronics. Thingiverse is a well-known site in the 3D printing field that offers various open designs for 3D objects. Anyone can use shared STL files to produce these objects with their own 3D printers. Thingiverse provides many tools, decorations, and various designs for microcontroller boards or single-board computers.
Arduino and OSHWA
One of the most well-known open hardware projects is Arduino, which provides microcontroller boards with an open-source development environment. The electronic schematics and design files for this development board are available under the CC-BY-SA license. This allows anyone to recreate these Arduino boards, although the registered trademark name of Arduino cannot be used.
However, it is somewhat strange that there are no official Arduino boards on the OSHWA certified open hardware list for such a well-known company in the open hardware ecosystem. These development boards seem to meet all the criteria defined by OSHWA, but Arduino chooses not to certify its products. It is even more surprising when you know that Arduino founders Massimo Banzi, David Cuartielles, David Mellis, and Tom Igoe are included in the list of supporters of the OSHWA definition and even helped create the definition of the project. However, when Adafruit recently asked Arduino if it would consider certifying any of its boards, the company declined.
However, aside from some missing design files and licensing errors, Arduino has consistently released all its development boards as open hardware. The situation has changed with the launch of Arduino Pro hardware, as Adafruit pointed out in a 2021 blog post. The product page for the Portenta H7 board only lists the circuit diagram and data sheet, omitting the design files needed to manufacture the board. For a long time, Arduino’s introductory page claimed, “All Arduino boards are completely open source, allowing users to build them independently and ultimately modify them to meet their specific needs.”
When Adafruit inquired about this discrepancy, Arduino’s Alessandro Ranellucci responded that for the Arduino Pro series, the company wanted to “prevent counterfeiters from blindly downloading files and manufacturing without doing R&D work or contributing to the community.” Thus, the company decided to release the circuit diagram without releasing the design files needed to manufacture that circuit board. The original statement on the introductory page has been removed, and the page now states, “The plans for Arduino boards are released under a Creative Commons license, allowing experienced circuit designers to create their own module versions, expand, and improve them.”
Currently, Arduino seems to be complying with its commitment to keep its “products for makers” as open hardware (albeit not OSHWA certified), but this is not the case for its Pro series; boards like Portenta C33 and Portenta X8 were released without accompanying design files. However, it is concerning that the latest non-Pro series boards, such as the Arduino Nano ESP32 and Arduino UNO R4 WiFi, do not even mention “open source” on their product pages or documentation. It is unfortunate that a large company like Arduino has not taken a clearer stance on open hardware.
As demonstrated by the OSHWA certification project list and other directories like OpenHardware.io, Kitspace, and Thingiverse, there is now a wealth of open hardware available. We can hope that Arduino will change its mind and commit to keeping its products for makers open, regardless of whether they are OSHWA certified. Arduino plays an important role in this field, not only in hardware but also in its software ecosystem. Fortunately, companies like Adafruit, SparkFun, and Olimex are putting significant effort into certifying their hardware. Therefore, those looking to build on OSHWA-certified hardware have many options, not just limited to Arduino’s development boards.
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