We have a little more information regarding our problem.

When using Visual GDB to create a new QT project for Raspberry PI, if the toolchain folder ‘C:\SysGCC\raspberry\Qt\v5-CMake’ doesn’t exist or is empty, the QT build tools are automatically downloaded and installed. The problem we are seeing is that the build tools end up being a different version (Qt v5.15.2) than what is being used on our target Raspberry Pi platform (Qt v5.12.3). This results in the following error produced by the moc compiler indicating that its attempting to compile using the much newer header libraries.

LinuxProject1_autogen/EWIEGA46WW/moc_MainWindow.cpp:80:18: error: 'QMetaObject::SuperData' has not been declared QMetaObject::SuperData::link<QMainWindow::staticMetaObject>(), ^~~~~~~~~

LinuxProject1_autogen/EWIEGA46WW/moc_MainWindow.cpp:80:65: error: expected primary-expression before ')' token
QMetaObject::SuperData::linkQMainWindow::staticMetaObject(),

Is there anything we can set in Visual Studio or elsewhere that will insure the downloaded Qt build tools match the Qt version on the target board?

This is our development environment

Windows 10
Visual Studio 2017
Qt Visual Studio Tools Version 2.8.1.6
Visual GDB 5.6R2
Qt build tools vers 5.12.3

And we are targetting Raspberry PI OS vresion Raspbian 10.

We are working around this problem by manually copying the odler set of build tools into ‘C:\SysGCC\raspberry\Qt\v5-CMake’ before making a new project using VisualGDB. We were fortunate that we had an older set of Qt build tools on another development PC to copy these from. This is not a good long term solution for us.

@helloworldddd said in DHT11 Sensor with RPI:

do u know how to use plot values to time, time as x axis on pyqtgraph?

Sorry, I never used pyqtgraph. Did you check its documentation?

Hi and welcome to devnet,

That's because you try to access a standard member variable from a static function.

Take a look at the ir_receiver example of the pigpio project. It shows how to use a class with the callback with gpioSetAlertFuncEx.

@Yalimyulad said in Post installing Qmake for new devices:

Is it possible to somehow copy the Qmake I have built from raspberry pi to my desktop?

Nothing is physically stopping you, but it won't work.

qmake is created and specific to the Qt FrameWork/Compiler used for that framework.
The compiler on your pi is not the same as the one you would use for cross compiling

If you want to really cross compile for the Pi , you will have to jump through some loops.
There are some guides out there for example this wiki entries

https://wiki.qt.io/Raspberry_Pi_Beginners_Guide
https://wiki.qt.io/RaspberryPi2EGLFS

I eventually found out that those changes mentioned in the links in the last post require you to set "QT_IM_MODULE=compose" but even then composing didn't work.

That being the case, I've reported a bug: https://bugreports.qt.io/browse/QTBUG-79097

I'm keeping this as unanswered until there is a workaround or a fix, but if you do not need dead keys or composition, just setting the XKB_DEFAULT vars and ensuring you are using libinput/xkbcommon should be enough to get your keyboard layout "working".

@olejl77 this is the article I'm actually following! But the gcc-linaro-arm-linux-gnueabihf-raspbian doens't support ICU:

https://github.com/raspberrypi/tools/issues/41

and I don't understand which compiler the Qt5 stuff had in mind when wrote the linux-rpi3-g++ mkspec file because the architecture and the compiler flags are not supported!

I confirm that adding the pthread library did the trick. But the question "why" is still there :)

Hi,

You have several wiki pages about Qt and the Raspberry Pi, see here for a start.

I have the same issue. Anyone got the solution ?