Questions tagged [qt]
a cross-platform application framework for developing application software
100
questions
1
vote
0answers
14 views
Horizontal lines on qt 5.13 app . Problem doesn't present with virtual screen (chvt) manipulation
I have a full-screen app in kiosk mode that runs on qt 5.13.2 (Qt compiled from source). Up until 1 week ago, it displayed just fine. Then, I did an apt dist-upgrade and I now get horizontal lines ...
1
vote
0answers
70 views
OpenCV cross-compilation fails
I have cross-compiled Qt on my CentOS host for my Raspberry Pi and now I want to cross-compile OpenCV with the following script:
CORES=4
IP=192.168.178.52
TEMP_PATH=/home/kampi/OpenCV
SYSROOT_PATH=/...
0
votes
0answers
47 views
How to start Qt application in startup console menu?
I have a simple Qt application that can be started over the Qt Creator from the host on the Raspberry Pi during the initial command prompt after booting by using egl.
But I got the error Could not ...
0
votes
0answers
911 views
Could not initialize egl display
I have a CentOS host which should be used to develop Qt applications (version 5.12.8) for a Raspberry Pi. I use the following Raspberry Pi setup:
$ cat /proc/cpuinfo
...
model name : ARMv7 ...
1
vote
1answer
433 views
installing qt on raspberry pi 4
I'm installing Qt to my raspberry pi-4 for image processing project. I use the commands:
sudo apt update
uname -a
apt-cache search qt5
apt-cache show qt5-default
apt-cache search qtcreator
apt-cache ...
0
votes
1answer
254 views
SIP Generator Error Installing ROS Melodic on Raspberry Pi 4
I've been attempting to install ROS Melodic on my Raspberry Pi 4 (running Raspbian Stretch) according to the instructions on this webpage:
[https://www.instructables.com/id/ROS-Melodic-on-Raspberry-...
0
votes
0answers
83 views
Qt5 widgets/QML not working on RPi4
Starting with this guide I compiled my Yocto environment for RPi4.
Some information:
# uname -a
Linux raspberrypi4 4.19.97 #1 SMP Tue Jan 28 13:52:05 UTC 2020 armv7l armv7l armv7l GNU/Linux
# qmake -...
1
vote
0answers
118 views
Cross-compiling QT interface to a Raspberry PI 3
I'm trying to install Qt interface to a Raspberry Pi 3, which raspbian is the "2016-05-27-raspbian-jessie".
I didn't want to install, directly, all the packages on the raspberry so as to let ...
0
votes
0answers
180 views
Raspberry pi - QT webenginewidgets problem
I use raspberry pi and QT (version 5.7.1). When I use
QT += webenginewidgets , I get an error
Project ERROR: Unknown module(s) in QT: webenginewidgets
however I try to install
-sudo apt-get install ...
1
vote
1answer
159 views
Cross-compile of Qt for Raspberry Pi fails for XCB support with updated toolchain
I had successfully cross-compiled Qt 5.11.2 for Raspbian Buster on Ubuntu 18.04 host mostly using these guides:
https://www.ics.com/blog/configuring-qt-creator-raspberry-pi
https://wiki.qt.io/...
2
votes
0answers
795 views
Why GLX or EGL is not enabled when running QT program?
To start with I have to say I was trying to make cross-compilation work for Ubuntu with Raspberry Pi 3+ B. I used this tutorial https://wiki.qt.io/RaspberryPi2EGLFS and QT in version 5.12.4. Tried it ...
1
vote
0answers
38 views
Compile Qt application on Raspberry Pi and Run that application on other ARM device. Will it work?
I am compiling One Qt application on Raspberry Pi and Run it on different ARM device like Microchip or TI board without compile again. will it work??? if both the side Qt version is same.
0
votes
0answers
45 views
MFRC522 and Bluetooth not work together
I have a program in which I use pyqt5, MFRC522 and bluetooth. I have 3 threads, one for the interface, one for the MFRC522 and one for the bluetooth. If I run the MFRC522 and the bluetooth separately ...
1
vote
1answer
389 views
symbol lookup error: undefined symbol: _ZN7QWidget8qwsEventEP8QWSEvent
I have cross-compiled executable file from QT 4.8.7. I am running it on a Raspberry PI (Ubuntu), with QT 4.8.7 and QT declarative module installed. When i run the executable file on my raspberry pi, i ...
0
votes
3answers
295 views
Configure Raspberry pi to run my application before GUI Desktop
I have created an application through Python that has library dependencies on Qt4, pyqt4, pyqtgraph etc. This application is based on Raspberry Pi, I have developed and finished it on the platform.
I ...
0
votes
1answer
104 views
How to use at the same time 2 hardware pwm in wiringpi
I need help to configure 2 hardware PWM channels. I am developing device, and sometimes I will need active 2 PWM channels with different frequencies (frequencies is low: 410 and 580 Hz).I'm writing ...
1
vote
3answers
2k views
How do I build Qt's mysql-plugin on Raspbian Buster
I try to build the MySQL plugin on a Raspbian Buster with C++ and Qt 5.12.4. Building Qt itself worked fine by following this tutorial: https://www.tal.org/tutorials/building-qt-512-raspberry-pi
...
1
vote
1answer
362 views
Failure to build QT5 5.12.3 on Raspberry Pi zero
Following the instructions in https://www.tal.org/tutorials/building-qt-512-raspberry-pi,:
wget http://download.qt.io/official_releases/qt/5.12/5.12.3/single/qt-everywhere-src-5.12.3.tar.xz
tar xf qt-...
2
votes
0answers
490 views
Qt cross compilation *QOpenGLShaderProgram: could not create shader program* error
I am using the QT Creator for my laptop (Linux LMDE 3 Cindy OS) And for Raspberry Zero Cross-compiling.
I have installed the QT based of this instruction and by this setting:
mkdir ~/raspi
...
0
votes
0answers
206 views
RaspberryPi2EGLFS guide - EGL/GLES libraries fix fail
I built Qt 5.12.3 for Raspberry Pi following the RaspberryPi2EGLFS guide from Qt Wiki.
I was able to reproduce almost each one of the steps described in the guide, but on step 14 (EGL/GLES libraries ...
2
votes
1answer
54 views
Does a binary built on pi 3 will work on pi 2?
I'm building an app on a raspberry pi 3. I'm using Qt. Will the generated binary work on raspberry pi 2?
Thanks
1
vote
1answer
567 views
Raspberry Pi 3 B+ QMediaPlayer - unable to play sound
I'm struggling to play audio files using Qt 5.11.3 and the QMediaPayer class.
There is no sound output when playing either .mp3 or .wav files.
I had some success to play a wav file using QSound class.
...
0
votes
0answers
28 views
The application stalls when the service is loaded at startup
I have RPI3B + with Raspian Stretch on which I run the QT application.
When I create my service to launch the application after starting the rpi i have problems.. The application starts and then the ...
1
vote
0answers
165 views
Raspberry Pi Qt toolchain on Ubuntu 16.04
I have issues creating a tool-chain for cross compiling Raspberry Pi 3 Qt applications through Ubuntu. I used directions from this guide, https://wiki.qt.io/Raspberry_Pi_Beginners_Guide, to help me ...
2
votes
0answers
908 views
Latest Qt5 does not provide EGLFS during cross-compilation
Some time ago I set up a Linux host to cross-compile Qt5. I used this configure command:
./configure -release -opengl es2 -device linux-rasp-pi3-g++ -device-option CROSS_COMPILE=~/opt/tools/arm-...
1
vote
1answer
205 views
Qt Userland raspistill/racpicam integration - Unable to find an X11 visual which matches EGL config
I am developing simple gui app for a client on Raspberry pi running Ubuntu(Mate) 16.04 using Qt 5.5.1 and OpenCV for some face recognition (all C++) using 5MP pi camera.
The framerate/CPU usage ...
1
vote
2answers
365 views
Socketcan and Qt on raspberry pi
Is there a prebuild serialbus library for Raspberry Pi? I would to use
QtCanBus in a project.
Unfortunately I cannot find any reference for installing the necessary library.
tried
sudo apt-get ...
0
votes
1answer
164 views
How can I use the free version of Qt to create a GUI for the Raspberry Pi?
I am working on a project that requires high-medium quality GUI. I am thinking of cross compiling from Windows to Raspberry Pi or from Ubuntu to Raspberry Pi. Also, I do not know which one of those ...
0
votes
0answers
67 views
Can't install development files for QT on RPi Zero W
I've been following this tutorial trying to get working QT cross-compilation from my PC to a Raspberry Pi Zero W.
It is failing on Step 5 ("Install a bunch of development files").
Running sudo apt-...
1
vote
1answer
2k views
(Error trying to run qjackctl) libEGL warning: DRI2: failed to authenticate qt5ct: using qt5ct plugin
Running Raspbian installed with NOOBS. qjackctl is installed with all its dependencies using Synaptic. Just trying to run Guitarix on my Pi3 B+. I tried following the instructions in this solution, ...
1
vote
1answer
102 views
How to detect if camera is unplugged from CSI bus when it is running?
I am having an issue as below.
I make a Qt application to show video got from the camera module. And when showing video, if the camera is unplugged from CSI bus, I must know that and show a warning ...
1
vote
1answer
1k views
Qt 5.11.1 install: run configure with options
I am new to the whole installing via the console thing.
I try to install Qt 5.11.1 native on my Raspberry Pi 3 with Raspian Stretch according to this tutorial: http://www.tal.org/tutorials/building-qt-...
0
votes
0answers
309 views
cross compile Qt 5.7 for rpi3 : help needed
i am trying to cross compile QT 5.7 for rpi 3 and following following links for the same:
https://www.ics.com/blog/configuring-qt-creator-raspberry-pi
https://wiki.qt.io/RaspberryPi2EGLFS
on ...
1
vote
1answer
2k views
Access RPi's camera stream in OpenCV C++ (Qt)
I've setup my Raspberry pi 3 B with uv4l and have access to the video stream on
http://(raspberry-IP):8080/stream address.
Now, I have Qt5(C++) and OpenCV installed on my main computer.
How can I ...
0
votes
1answer
213 views
PyQt5 / eglfs: Draw call returned Cannot allocate memory. Expect corruption
Rather sure this is not a PyQt specific question, but that's the context.
When attempting to start a PyQt5 from CLI/text mode into eglfs, I am met with the following errors:
QOpenGLFramebufferObject:...
0
votes
1answer
952 views
QCamera get error “mesa-loader failed to retrieve device information”
Qt test code:
QCamera* camera = new QCamera;
auto viewfinder = new QCameraViewfinder();
camera->setViewfinder(viewfinder);
viewfinder->show();
camera->start();
Output:
mesa-loader failed ...
1
vote
1answer
387 views
Qt Application crashing on Raspberry Pi 3 with Adafruit 2.8" PiTfT touchscreen
I have a adafruit PiTfT 2.8" 320x240 capacitive touch display running on a raspberry pi. I cross compiled my executable under linux, where I also cross-compiled qt. If I run the enclosed example ...
-1
votes
2answers
4k views
Run Qt Application on Startup [duplicate]
I want to make my qt project run while booting raspberry pi3. When I searched on the web there is a solution for python. Eventhough I put some code on rc.local, this did not solve my problem.
The ...
1
vote
0answers
654 views
Qt5.10.1 Cross-Compiled to Raspberry Pi Zero W uses EGLFS instead of XCB
I have been trying to create a GUI application using Qt5 on Raspbian Stretch, but the application doesn't launch correctly unless I specifically tell it to run as XCB. This is fine, as I don't need it ...
0
votes
1answer
1k views
C++ GUI development with graph support
So, I am developing a project in the RPi where I will be reading values from a sensor using I2C, and this values will be plotted in real time using a GUI. The project is strictly being developed C++ (...
0
votes
1answer
122 views
How can i listen to input in very precise manner of microseconds. Like piscope. Using pigpio socket interface, pigs or liberary
I want to get time and count of input pulse in microseconds using pigpio. How can i Listen to gpio pin in spreate thread.
1
vote
0answers
1k views
PyQt support for WebEngine on raspberry Pi 3 raspbian-stretch
I have installed PyQt5 for Python3. However while I can import various modules into Python I am finding that none of the WebEngine modules import (WebEngine, WebEngineWidgets, WebEngineCore). They ...
2
votes
1answer
7k views
ImportError: No module named 'PyQt5'
I am trying to get the script here to work on Raspberry Pi. I have tested it on Windows and Ubuntu and it works fine. But getting pyqt5 working on RPi seems to be a challenge. On Ubuntu the following ...
1
vote
2answers
2k views
How to get qt4 runtime libraries
The latest (stretch) image has dropped all qt4 libraries and has qt5 libraries instead.
But I still have A LOT of qt4 software. I have searched the web but every hit tells me how to install the qt4 ...
-1
votes
1answer
31 views
Variables dont get initialized [closed]
i am programming a GUI with Qt5 that uses 4 buttons that turn a stepper motor.
I just took this setup i found on the internet.
Here is my code:
from PyQt5 import QtCore, QtGui, QtWidgets
from time ...
-1
votes
1answer
375 views
How can I move my normal c++ main() function code to qt main function?
I have created small normal c++ code to test in raspberry pi which is working perfectly fine on the terminal.Now I want to write it down in qt, the problem here I am facing is I can able to move my ...
1
vote
2answers
7k views
Jessie: libEGL warning: DRI2: failed to authenticate
I'm developing an application using Python 3 / PyQt5. Everything seems ship-shape until I try to run the GUI (which is partially reliant on a live graph that is backed by pyqtgraph) on my Raspberry Pi ...
1
vote
1answer
1k views
Disable default bluetooth dialog box for accept pairing in raspberry pi3
I am developing a Bluetooth application using Qt5 on Raspberry Pi3. I have implemented my own Pairing agent which will automatically accept the pairing request from the remote device.
The code is ...
0
votes
0answers
1k views
Malfunction with Qt5 and touch screen on RPi3
I develop a Q5 embedded application on RPi3 and I'm having trouble with the touchscreen.
My problem: The touch area is stretched.
In the picture below, the touch area of the buttons at the corners ...
1
vote
0answers
757 views
Problems with PyQt5
Quoting:
I developed a similar application using PyQt4 and Qt4-designer. You
have to install pyqt4 all modules:
sudo apt-get install qt4-default qt4-designer qt4-doc qt4-dev-tools
python-...
