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
We change the code of our Qt application in QtCreator and press the Run button to try the changes on an embedded device. QtCreator cross-compiles the application, deploys it to the device and runs it on the device. QtCreator performs these steps in a breeze, because we spent quite some time to define a QtCreator Kit. The fairly unknown script configure-qtcreator.sh from the Yocto layer meta-boot2qt automates most of the kit definition.
Read More »Cross-Compiling Qt Embedded Applications with QtCreator and CMake
A fairly common anti-pattern found in Qt applications is to derive a class MyApplication from QApplication and to have it hand out pointers to a… Read More »Breaking Dependency Cycles in Qt Applications
We want to develop the Internet radio application for the Raspberry Pi in the same way as for a PC. We change the source code in QtCreator and run the application. QtCreator cross-builds the application on the PC for the Raspberry Pi, deploys it with SSH to the Pi and runs it on the Pi. We need a Qt SDK for this to work. In addition to the target libraries from the Linux image, the Qt SDK contains the library headers, a cross-compiler, a cross-linker, a cross-debugger and more.
Read More »Qt Embedded Systems – Part 2: Building a Qt SDK with Yocto
In Part 1 of the series on Qt Embedded Systems, we build a custom Linux image with Yocto for the Raspberry Pi 3B. When we… Read More »Qt Embedded Systems – Part 1: Building a Linux Image with Yocto
On 8 April 2020, Olaf Schmidt-Wischhöfer wrote in an email to the KDE community (emphasis mine):
[…] last week, [The Qt Company] suddenly informed both the KDE e.V. board and the KDE Free QT Foundation that the economic outlook caused by the Corona virus puts more pressure on them to increase short-term revenue. As a result, they are thinking about restricting ALL Qt releases to paid license holders for the first 12 months.
To be clear: Nothing has been decided yet. I certainly hope that this “thinking” by The Qt Company remains just that: thinking. But I am not quite sure.
Read More »FOSS Qt Releases Delayed by up to 12 Months?Bob builds Qt for the development team on a fast compute server. He packs Qt into a tarball and hands the tarball to his teammates. Alice installs the Qt tarball on her PC in a directory that differs from the installation directory used by Bob. As the target embedded system runs on an AMD Ryzen SoC with x86_64 architecture like the build server and the development PC, Alice installs Qt on the target system – yet in another directory. She can then try out the latest changes of her app directly on the target system. As Qt is relocatable since version 5.14, Alice’s and Bob’s jobs have become quite a bit easier.
Read More »Benefits of a Relocatable QtFrom Qt 5.15, The Qt Company make their offering a bit more inconvenient for FOSS users. They announced three changes:
What do these changes mean for the development of Qt embedded Linux systems under LGPLv3?
Read More »Less Love for FOSS Qt Users