I've managed to figure out the issue.

It turns out that I needed to disable power management signalling (dpms). I added the following lines to my /home/pi/.config/lxsession/LXDE-pi/autostart file -

@xset s off
@xset -dpms
@xset s noblank

The GUI now remains fully responsive even after a full day of running.

Thank you for your time @SGaist

Hi,

Absolutely, in the same creator session I can toggle between toolchains, Desktop is fine, but Raspberry Pi is giving the aforementioned problem.

This is my setup.

Build settings:

0_1553262032384_d234256c-f6e3-4acc-b861-0d5153f80f23-image.png

0_1553262575907_7783d3e3-39a4-4a2b-aeb7-1c640598b17a-image.png

PATH: /home/ubuntuvm/raspi/qt5/bin:/home/ubuntuvm/raspi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/arm-linux-gnueabihf/bin

Kit:

0_1553262136401_a8f684d0-8005-41d0-bc94-de018e3acb28-image.png

Device:
0_1553262784829_a5f27b5f-bf3a-49c7-ac08-492f4ef2294d-image.png

Qt Versions:
0_1553262183514_7324f48e-e118-4fbd-b86b-1624dbe84544-image.png

Compilers:
0_1553262236958_3e5d5c9f-8dc7-4338-b094-cd6c40d6fcc9-image.png

0_1553262396408_495b7c91-9b03-4db2-9ec8-2c84ca13b1c3-image.png

Compiler Path (C & C++):
/home/ubuntuvm/raspi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/arm-linux-gnueabihf/bin/gcc

Debuggers:
0_1553262259546_0a0a3f73-c0d0-48b8-990c-8cd188d9f208-image.png

Qbs:
0_1553262324062_2ee32585-94a3-4b22-a956-0f44ed63657e-image.png

I also encountered this problem. It can be solved by manually adding the following definition of this structure (from Raspberry Pi Video Core API) into EGL/eglplatform.h (adding additional definition will not break compilation on non-legacy code that does not use this structure). And you also need to add the definition of DISPMANX_ELEMENT_HANDLE_T before that. i.e.,

typedef uint32_t DISPMANX_ELEMENT_HANDLE_T; typedef struct { DISPMANX_ELEMENT_HANDLE_T element; int width; /* This is necessary because dispmanx elements are not queriable. */ int height; } EGL_DISPMANX_WINDOW_T;

After doing this, you will still encounter a few compilation errors in pointer casting. You can just forcefully cast all pointers over (or copy my code ). The compilation should proceed then.
The reason why the compilation breaks is because in the open-source community, many developers still come from private companies working on proprietary projects. Some need to show to their boss that they have done something, so they unnecessarily keeps changing definitions, names, removing structures they do not know about due to their ignorance on other platforms/architectures (so they can say "oh, I did code-base clean-up"). In the end, it causes massive compilation breaks/failures. However, the underlying code is still the same, that is why directly casting pointers over surprisingly works out in the end, which should not be the case if substantial development is present. In summary, the No.1 development principle is that code modification should be made as minimal as possible and should exist if and only if necessary.

@Saman19 said in using Jsoncpp library in Qt on Raspberry pi 3:

/media/saman/62ca0b6d-6291-4c40-b1fd-11bc291e4a38/usr/lib/libjsoncpp.so

Please show the output of the commands file /media/saman/62ca0b6d-6291-4c40-b1fd-11bc291e4a38/usr/lib/libjsoncpp.so ldd /media/saman/62ca0b6d-6291-4c40-b1fd-11bc291e4a38/usr/lib/libjsoncpp.so Any reason you don't use Qt's built-in JSON support?

@kickoune103 said in error after start example qt5.8 for raspberrypi:

-v it's use before.

Then please post the actual configure output (at least the part where fontconfig is being tested).

@paul_espinosa thanks ,, worked for me also installing Qt-5.7.1 on armhf

@Fernando-Melo

Hi,

just build a cross compile for Raspi.

I ran into the same problem with 5.11.3 what is old, but comes with Raspi 4.

Your receipe solved this, but no root has been required.

I ran:

WORK=$PWD
cd ./qtlocation/src/3rdparty/clip2tri; make ; cd $WORK
cd ./qtlocation/src/3rdparty/clipper; make ; cd $WORK
cd ./qtlocation/src/3rdparty/poly2tri; make ; cd $WORK

Beside that. There are other compile issues related to incompatiblty.

I skipped them by skipping the problem modules by adding this to confguire:

-skip qtwayland -skip qtlocation -skip qtscript

(thanks to: https://mechatronicsblog.com/cross-compile-and-deploy-qt-5-12-for-raspberry-pi/)

Marko

Sorry to resurrect an old topic, but how did you manage to configure Qt on os x? I'm using Jared Wolff's toolchain but get stuck at ./configure and can't build a RPi-friendly qmake.

@BruceNaylor Hmm that's interesting! I posted on the C++ Gurus forum and a couple guys there suggested I use the MinGW that gets installed with QT Creator (when you select that option) and that actually fixed my issue with registry keys. I was going to give cross compiling another try on Windows, maybe your fudges will fix some other issues I've into. I appreciate the suggestions!

I moved to QT 5.5 and it works prefectly when i have another process triggered the oxmplayer which it is running underneath of my applicatioin.

thanks.

Hi,

Where did you get this library from in the first place ?

Here is the catch

you have to use arm-linux-gnueabihf-'' instead of arm-linux-gnueabihf.

@SGaist thanks for your help

Hi and welcome to devnet,

What are you doing in the processing part ?

Solved: Now I use wayland-egl and everything is fine.

The Long Story to Get the Simple Solution:
At first, I used raspberrypi-userland for OpenGL ES. However, it didn't work.

I tried VC4 DRM driver in the next. I have struggled to get it work, and I opened an issue on the repository. Then anholt, the author of the driver,
updated the Wiki. By following the Wiki, I finally succeeded in getting it work.

mesa3d is necessary to provide OpenGL ES API, so I installed it with drm backend. However, it didn't work since eglCreatePbufferSurface is stubbed in the backend. So I had to use other QPA.

Next, I tried X11 since Buildroot supports xcb backend, but neither did it work. I thought porting Wayland should be much easier than fixing the issue, and actually it is.

Then I'd recommend taking a look the example code and rewrite yours to match it.