Burkhard on Qt Embedded Systems: No. 3
Welcome to Episode 3 of my newsletter on Qt Embedded Systems. I lead this episode with my thoughts about a better pricing model for Qt. What price would you be willing to pay for Qt and why? I am keen
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Benefits of a Relocatable Qt
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
Less Love for FOSS Qt Users
From Qt 5.15, The Qt Company make their offering a bit more inconvenient for FOSS users. They announced three changes: * A Qt account is mandatory to download binary Qt packages. The offline installer is not available to FOSS users
Burkhard on Qt Embedded Systems: No. 2
Welcome to my newsletter on Qt Embedded Systems. In my monthly newsletters, I cover a large spectrum of topics needed to build Qt applications on embedded systems. Topics include UI design, QML, Qt, C++, Yocto, system-on-chips, system architecture,
QML Engine Deletes C++ Objects Still In Use - Revisited with Address Sanitizers
Two years ago, I spent three days to figure out why the driver terminal of a sugar beet harvester crashed (see my original post). The crash happened after going through the same six-step interaction at least four times. The
Introduction to the SAE J1939 Standard
In the early days of controller area networks (CAN), every device manufacturer interpreted CAN frames in its own proprietary way. When you changed the engine of a harvester from Volvo to MAN, you would have to reimplement the communication with
Safe-Guarding the (L)GPL Future of Qt
The little known KDE Free Qt Foundation makes sure that Qt stays free and open-source. It guarantees that all Qt modules currently licensed under LGPLv3 must continue to be available under LGPLv3 in the future. This covers all modules
Detecting Overdraw in QML HMIs with GammaRay
Overdraw happens when one QML item fully eclipses another QML item. The QML renderer always draws both items, although there is no need to draw the eclipsed item. You must help out the renderer by explicitly setting visible: false on
My talk "A Deep Dive into QtCanBus" at Qt World Summit 2019
The screenshot above shows the home screen of a sugar beet harvester. The home screen receives roughly 50 CAN messages per second and displays the contents of the CAN messages numerically or graphically. Every number on the home screen is
Comparing Two Floating-Point Numbers
The mathematician Leopold Kronecker is believed to have said: God made the integers, all else is the work of man. And Kronecker didn't even know the floating-point numbers "made" for computers. Comparing two numbers of
QTest: Data-Driven Unit Tests Are Hard To Understand
Today, I looked at the data-driven unit tests I had written nearly four weeks ago. It took me a couple of minutes to understand the tests again. Understanding my own tests should have been much easier. Data-driven unit
QCOMPARE with Custom Qt Types
When you write unit tests, you will have to compare the actual value and the expected value. A simplified example with QStrings would look like this. void MyTest::testQCompare() { auto actualStr = QString{"abba"}; auto expectedStr = QString{"juhu&