Embedded Linux and IoT specialist
Bart Cerneels
Owner/Developer
I'm driven by the passion of computing enabled devices in industry, home, office and public spaces for automation, mobility, energy, comfort...
Why "The Appli Tree"?
I built my zero-energy solar-passive house in the middle of the Belgian fruit producing region. Along with strawberry, cherry and pears, the main crop is apples of the Jonagold variety.
A pun involving apples was obvious. But since we’re not an Apple Computer shop, “Appli” was used as short for applications, but also Linux, the kernel not only found on our laptops, but also smartphones, NAS, home automation, car infotainment system and household robot.
A tree branches of it from a common trunk into many different leaves.
Like well written and maintained source code a common trunk can adapt to run on multiple platform and for various use cases.
The roots gather nutrition and water from a wide area. The Open Source software world is a fertile forest floor with many sapling projects and fallen leaves, but it takes experience to gather these elements and use them successfully in commercial projects.
Any sufficiently advanced technology is indistinguishable from magic.
Arthur C. Clarke
Skills
Software Engineering
Specifications and requirement gathering. Prototyping to test out concepts. Working with other developers to achieve the goals with
efficient and maintainable implementations.
I’ve worked on every layer in the IoT “cake” from hardware up to cloud and some mobile app UI but certainly am most comfortable and skilled on the embedded side.
I see the bigger picture thanks to my experience: Often a feature is easier, cheaper to implement and quicker to deploy in the cloud than on the IoT module.
Devops and CI tools
git expert since 2007 in the KDE project, the 2nd multi-million LOC project to switch over (after linux itself).
Jenkins for code quality and hardware in the loop testing using pipelines and github and gitlab integrations.
Jira and other Atlassian tools are most common in the industry for scrum but for my own projects I prefer github’s bug-tracking and kanban tools.
Embedded Software
C and C++ for embedded code, hoping for more modern embedded language (rust?). Python for scripts and testing. Make, CMake for build infra.
Board bring-up, BSP, build systems and continuous integration (CI). Embedded Linux, Zephyr, FreeRTOS, bootloaders and bare metal on ARM, PPC and MIPS architectures used in telecom, automotive, IoT and space!
Personality Traits
Strong in verbal and written communication and very outgoing. Enthusiastic and ambitious in exploring technological limits. Natural tendency towards innovative solutions and out-of-the-box ideas. Critical yet pragmatic. Flexible and self-motivating.
Hardware
I help select architectures and components and review designs and schematics from the perspective of the software engineer that would bring up the board and do low level development. This means diving into datasheets, finding those crossed RX/TX signals, freeing up IO with clever tricks, etc.
Special Interests
Home automation, electric transport, “Internet of Things” products, Smart-grids & renewables, Energy efficiency and sustainable technology in general.
Self-built a solar powered zero-energy house in 2010, driving electric since
2016.
Debugging
Deep dive into problems with debuggers, hardware probing & test setups. Questioning easy answers until confident of a long term fix.
Wireless Protocols
Bluetooth EDR/BLE (Nordic Stack), TCP/IP (incl. v6), WiFi, Thread, Zigbee, Z-Wave.
Languages
Dutch: native
English: advanced professional
French: professional
Projects
The HERA mission of ESA launched in October 2024 aboard with a SpaceX falcon 9 carrying Juventas, a cubesat that will probe Dimorphos – the orbiting moonlet of a binary asteroid system known as Didymos.
The main Command and Data Handling codebase is written in C, with aerospace quality standards. It runs as a systemd service on the Yocto based linux OS along with sensors and navigation processes. Everything has to work together and be stable so the focus was on system level integration testing on actual hardware, which was a very limited resource.
I created as-flight use-case verification tests in python and implemented some extra features for the Yocto based linux OS. Specifically enabling the low-frequency radar JURA payload and various supporting functionality.
Resource limitations and system complexity caused regular deep diving into challenging bugs so the science mission will hopefully be a success
when it arrives at the asteroid at 1.71 AU from the sun in December of 2026.
SmartBMS is an offline IoT system based on Nordic multicore BLE MCU and C++ Zephyr based firmware. Even though it does not have a modem we manage to offer the same data state, telemetry and remote commands via Bluetooth Low Energy, a background smartphone application and a cloud command and control system. For BikeBat this provides a way to offer extended warranty with lifetime optimized charging, remote diagnosis and a platform for other applications of e-bike brands.
BikeBat was a customer of e-motionlabs with a long running project. Because of the silicon crisis and Bond’s bankruptcy their project was in risk of failing after many delays. Together with 2 colleagues from Bond we continued the project directly for BikeBat with almost from scratch hardware and firmware to work around unavailable components and IP issues. After the initial kickoff I was available on call and my former team-members continued the project on
BikeBat’s payroll.
We had plans to turn this “Offline IoT” into a dedicated business.
Bond AG in Switzerland acquired e-motionlabs based in Hasselt in 2021. For various customers and Bond’s own shared speed-pedelecs we designed IoT modules: hardware, firmware and production testing. I was the tech lead defining the platform and project managing a team of 5 HW and FW engineers. We developed multiple ARM based platforms with modems and BLE on board with a common, custom bare-metal C++ firmware to allow maximum reuse.
Also supported a legacy Arduino based system and follow-up of vehicle integration and BMS issues with the Taiwanese suppliers. The C++ firmware was originally developed by Particle studios (engineering services of particle.io) and not of good quality so many refactorings were needed to increase reliability and make it fit for purpose.
Bond AG had to declare bankruptcy on 2021-09-16 after failing to get funding. Bond Belgium was left in limbo without paying its employees. I helped to follow up proceedings to hopefully rescue some IP and assets for a new venture.
Board bring-up. From scratch BSP, build system and firmware architecture of the 2019 model.
BLE driver and custom services, with various encryption levels. Workaround for iOS bonding particulars.
Software design for manufacturing to ensure quality control yet improve tack time. In line final device upgrade.
Multi-channel data transport via BLE + 2G using custom Protobuf based protocol.
On-board diagnostics for robust control, fault detection and automatic workarounds for hardware issues.
Specifying requirements of the backend and apps, solving integration bugs.
Supporting internal engineering, suppliers, manufacturing, customer support channels.
Platform and application work for high performance video processing and display for digital cinema and specialized applications.
Worked with buildroot to create the platform and C and C++ for application and kernel. Board bring-up and debugging of u-boot and linux kernel. Network delivery and video processing using libav (ffmpeg).
Jabil Hasselt offers design services for electronic products to companies all over the world. For a Dutch fast-growing company a touch screen, ARM based multi-communications product was developed. I worked on the yocto based BSP which included U-boot and Linux board support and low-level drivers; diagnostics software for production and engineering including flashing, serialization, low-level IO access, RF communications, hardware debugging and testing.
Continued working on linux driver, build system and FreeRTOS for the Cortex M4 processor core.