Open source: a major asset in the design of IoT products

Given these challenges, open source is the obvious choice. Over 70% of companies in the sector are adopting it to speed up development, reduce costs and enhance the security of their connected products.

Let’s explore together why open source has become essential in the design of high-performance IoT solutions.

What is open Source?

It is often thought that open source simply means freely accessible code. But it is much more than that! It also encompasses frameworks, software and even hardware, which anyone can view, modify and share freely.

It is based on a philosophy of collaboration and knowledge-sharing, thereby fostering collective innovation.

This approach allows businesses to benefit from an active community of experts who continually enhance existing solutions, thereby ensuring robustness and security.

Why choose open source for your IoT project?

IoT projects face complex challenges: scalability, interoperability, data security, long-term maintenance and budgetary constraints. Open source offers ready-to-use solutions to address these effectively.

One of the main advantages of open source lies in its collaborative nature. Rather than developing from scratch, companies can draw on libraries, frameworks and solutions that have already been tried and tested by a large community of developers and experts.

This dynamic ecosystem enables the rapid integration of advanced features, whilst benefiting from continuous code improvements thanks to contributions from the community.

Here’s how open source helps tackle the technical challenges of the IoT:

• Robustness: Its code is sometimes reviewed by thousands of people. Thousands of experts in their fields can contribute to it and help shape the project on the best possible technical foundations.
• Sustainability: It is easier to maintain code when it is managed by a large community. This allows the open-source project to evolve and endure over time whilst incorporating the latest technological advances.
• Enhanced security: Security through obscurity has its limits. Reverse engineering is always possible, as are code leaks. Whereas source code transparency enables constant scrutiny, which facilitates the detection and correction of vulnerabilities. Open and public code thus enhances security by allowing the community to contribute to its improvement.
• Cost optimisation: Although the initial investment may be substantial, open source helps to limit licensing costs and benefit from community-driven maintenance.

The must-have open-source solutions for IoT

The open-source ecosystem is brimming with tools specifically designed for the IoT. Here are some of the leading solutions:

For the embedded system

• Linux: the most widely used open-source operating system, found in a wide range of internet boxes, industrial gateways and medical equipment.
• FreeRTOS: a lightweight real-time operating system, integrated into devices such as smartwatches and smart meters.
• Zephyr: a modular operating system for connected devices, supported by Intel, Nordic and NXP, suitable for sensors, wireless modules and portable medical devices.
• RAUC: a robust update system for embedded Linux, used in critical deployments (automotive, energy, etc.).
• Yocto: a build infrastructure for creating customised and optimised Linux distributions

For connectivity

• MQTT: a lightweight messaging protocol, used for example in home automation systems to transmit data quickly.
• CoAP: a protocol optimised for the IoT, often used in industrial sensors.
• OpenThread: an open-source implementation of the Thread protocol, used notably in Google Nest products to create reliable mesh networks.
• LwM2M: a protocol for managing IoT devices, particularly suited to cellular networks (NB-IoT, LTE-M). Used in industrial M2M solutions.

For safety reasons

• OpenSSL: a cryptography library used to secure communications, for example in remote software updates.
• WolfSSL: a version optimised for embedded systems, used in resource-constrained environments such as drones or automotive systems.

Best practices for an open-source IoT project

The success of an open-source-based IoT project requires a methodical and well-considered approach.

To get the most out of open source, here are a few guidelines to follow:

• Assess the maturity of projects: Activity on GitHub, commit frequency, responsiveness to issues… These indicators help ensure you don’t rely on abandoned projects.
• Check licence compatibility: GPL, MIT, Apache… certain licences may impose significant restrictions. It is crucial to understand them beforehand.
• Get involved in the community: By reporting bugs, asking questions or contributing to the documentation, you are actively participating in the project.
• Set aside time to contribute: Don’t just consume, but also nurture the ecosystem. It’s an investment that benefits everyone.
• Take care with the documentation of your contributions: This facilitates maintenance and reusability, and strengthens confidence in your technical choices.

Why is Rtone committed to open source?

In a world where technological innovation is evolving at breakneck speed, by not reinventing the wheel and by drawing on the collective expertise of specialists in their respective fields, we are able to achieve more, faster.

At Rtone, the values of sharing and collaboration are part of our DNA. We do not offer our clients individual experts, but rather a group of experts who are able to work together and exchange ideas to deliver the best solutions for your projects.

Open source fits perfectly with this vision because it embodies the power of collective work and shared intelligence.

We embrace it to:

• Accelerate our development whilst ensuring high quality.
• Gain mastery over the solutions we integrate into our clients’ products.
• Actively contribute to the ecosystem by sharing our expertise.

Our open-source contributions to the IoT

We are also actively involved in many of these open-source projects. Why?

Because, beyond our values, we want to have full control over the solutions we offer and on which we build our clients’ products.

As experts in Linux BSPs and MCUs, we have contributed to projects such as:

• Linux, Yocto, Barebox, Zephyr, Riot-OS for embedded systems.
• Azure IoT-Edge, Dolibarr, Ansible for cloud and full-stack solutions

Our expertise in action: the EDF Solutions Solaires case study

The EDF Solar Solutions project provides a concrete illustration of the benefits of the open-source approach. Our mission is to develop custom Linux firmware, based on Yocto, for CM3 and CM4s SoCs.

For over-the-air (OTA) firmware updates, we have opted for the RAUC + Barebox combination. This solution, which we are very familiar with, has the advantage of being lightweight and flexible, unlike other proprietary all-in-one solutions, which are powerful but can incur significant costs when charged per device. As managing remote updates is a key challenge for any IoT project, we have dedicated an entire article to OTA updates to share our best practices and feedback.

Whilst RAUC provides good abstraction from the target platform, the Barebox bootloader, although it supports numerous platforms such as the CM3 and CM4, did not yet support the CM4s at the time of our development. We therefore contributed to the integration of this support, thereby strengthening the open-source ecosystem in the process.

Collaboration with the Barebox community

Faced with the lack of support for the CM4s in Barebox, we quickly reached out to the community via their mailing list (http://lists.infradead.org/mailman/listinfo/barebox) and their IRC channel (https://web.libera.chat/#barebox). The aim was to outline the issues we’d encountered and gather suggestions for solutions.

Ahmad Fatoum from Pengutronix, one of the project maintainers, was our main point of contact. Thanks to his feedback, we were able to identify two major sticking points:

• The CM4s device ID was not recognised by Barebox.
• No Device Tree Source (DTS) specific to the CM4s existed; although similar to the CM4, this SoC required some adjustments.

A beneficial contribution to the wider ecosystem

We then proposed a series of patches ([1], [2]) to add support for the CM4s in Barebox. This contribution was quickly integrated by the maintainers.

This collaborative effort proved to be a win-win situation:

• For the community: the CM4s is now officially supported, which benefits other projects using this platform.
• For our team: an implementation validated by the maintainers, robust, and compliant with the project’s best practices.
• For our client: a sustainable solution integrated directly into the project, without resorting to costly proprietary solutions.

Ultimately, this collaborative approach enabled us to quickly resolve our issue whilst contributing to the enrichment of the open-source ecosystem.

[1] https://lore.barebox.org/barebox/20231214163520.2232412-1-sebastien.bourdelin@rtone.fr/

[2] https://lore.barebox.org/barebox/20240215120109.23242-1-pierre-olivier.huard@rtone.fr/

The ROI of open source in the IoT

A concrete example: as part of our EDF Solar Solutions project, we saved tens of thousands of euros by avoiding the purchase of proprietary licences.

Beyond the immediate financial benefit, open source allows us to have complete control over our solution from start to finish, thereby ensuring its long-term viability. Developing support for our board in BareboxB and its official integration into the project required an investment of 20 man-days, a cost significantly lower than that of existing proprietary solutions.

Open source is proving to be a powerful lever for optimising costs and increasing flexibility in IoT projects. By using existing solutions supported by an active community, here are the main benefits:

• Reduced development costs: Using open-source software enables substantial savings compared to a proprietary solution.
• Faster time-to-market: Thanks to ready-made technology building blocks, development time can be significantly reduced.
• Lower maintenance costs: The community constantly contributes to improving the software, thereby reducing support and update costs.

As part of the EDF Solar Solutions project, open source has not only optimised the budget but also ensured the solution’s long-term viability.

A winning value-for-money choice

By using Barebox and RAUC to manage OTA updates, we have avoided paying for expensive licences, whilst retaining full control over the solution.

Complete mastery of the technology

The integration of CM4s support into Barebox has enabled us to avoid reliance on third-party suppliers. Unlike proprietary solutions, which typically charge per device, our approach offers us greater flexibility and reduces recurring costs.

A worthwhile investment

The development and integration of CM4s support into Barebox took 20 man-days. This effort not only met our immediate needs, but also benefited the wider open-source community.

So, instead of paying thousands of euros for proprietary licences, we invested in a robust, scalable solution that we control from start to finish. Open source is not just a cost-effective alternative: it is a strategic choice that supports innovation and the sustainability of IoT projects.

To find out more and discover the history of our collaboration, take a look at our case study for the Yuze project.

In conclusion

Open source has established itself as an essential driver for high-performance, sustainable and cost-effective IoT solutions. At Rtone, we put our technical expertise and commitment to the open-source ecosystem at the service of our clients to ensure the success of their projects.