I never got the hang of UML: overly complicated, hard to understand, too close to code. Hence, I was skeptical about C4 diagrams when I… Read More »Visualising the Architecture of Qt Embedded Systems: Context and Container Diagrams
I am using TDD to implement a hardware-independent mock QCanBusDevice. We can use MockCanBusDevice in unit, integration and acceptance tests – without access to a… Read More »A Mock QCanBusDevice for TDD
I gave a talk at Meeting Embedded 2021 on 4 November 2021. First, I introduced the hexagonal architecture (a.k.a. ports-and-adapters architecture) in general. Then, I showed a walking skeleton of the architecture for a harvester terminal.
Read More »My Talk “Hexagonal Architecture: The Standard for Qt Embedded Applications” at Meeting Embedded 2021
Creating an architecture means answering many questions about the ecosystem, in which the Qt embedded system operates. While the questions are very similar for all Qt embedded systems, the answers and their priorities differ. So, you should be able to transfer the questions and answers from my running example, a harvester terminal, to your system.
Read More »My Talk “A Successful Architecture for Qt Embedded Systems” at Qt Day Italy 2021
Our quest for a successful architecture of a harvester terminal continues. In this episode, we discuss when a system with a single application is good enough and when a system with multiple applications and a window manager is the better choice. Sometimes, a single-application system with a window manager is just the right choice.
Read More »Architecture of Qt Embedded Systems: Single vs. Multiple GUI ApplicationsNearly exactly 5 years ago, I wrote my first article about Using Qt 5.6 and Later under LGPL. The trigger then was the switch from LGPLv2.1 to LGPLv3 with Qt 5.6. The trigger now is the switch from Qt 5 to Qt 6. All the Qt modules under LGPLv3 5 years ago are still available under LGPLv3 – unless they have been retired. Some new modules like Charts, CoAP and MQTT were only available under Qt Commercial until Qt 5.15, but are now available under the new Marketplace license for 50-300 USD per year (no royalties). Some new modules like Quick 3D and WebAssembly are only commercially available. All in all not much changed: You can still build fantastic HMIs with Qt LGPLv3.
Read More »Using Qt 5.15 and Qt 6 under LGPLv3
Our Qt embedded system is displayed on a monitor mounted in portrait orientation. The system runs the Wayland compositor Weston as a window manager. HMI applications are shown rotated by 90 degrees – in landscape orientation. The system toolbar of Weston is visible. How can we configure Weston so that the applications are shown in portrait orientation and so that the system toolbar is removed?
Read More »Showing Wayland Compositor Fullscreen in Portrait Orientation
September 2021 saw the launch of Qt 6.2 – the first Qt 6 version with feature parity to Qt 5.15. I wanted to find out whether Qt 6.2 is fit for products. So, I migrated the HMI application of the ROPA sugar beet harvesters from Qt 5.12 over Qt 5.15 to Qt 6.2. The migration went very smooth and quick. And yes, Qt 6.2 is fit for products!
Read More »Migrating a Harvester HMI from Qt 5.12 to Qt 6.2
Which system-on-chip is best suited for your Qt embedded system? Should you build a custom Linux system with Yocto, use a container OS or a desktop Linux? Should you use Qt Commercial or Qt LGPLv3? How will the system be updated? What are the operating conditions of the system? How does the system communicate with sensors, ECUs and the cloud?
This is only a small selection of the 50+ questions in this post. You best tackle these questions early in the project. Fixing wrong decisions becomes exponentially harder with the duration of the project. Your decisions can make or break a project.
Read More »Architecture of Qt Embedded Systems: Getting Started