Questions tagged [qt]

a cross-platform application framework for developing application software

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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=/...
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28 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 ...
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0answers
401 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 ...
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1answer
220 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 ...
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1answer
176 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-...
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0answers
72 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 -...
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0answers
102 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 ...
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0answers
113 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 ...
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1answer
135 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/...
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0answers
594 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 ...
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0answers
37 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.
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0answers
43 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
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1answer
339 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 ...
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2answers
187 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
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1answer
98 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
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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
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1answer
309 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
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0answers
456 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 ...
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0answers
183 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
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1answer
51 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
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1answer
449 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. ...
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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
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0answers
163 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
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0answers
818 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
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1answer
191 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 ...
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2answers
316 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
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1answer
152 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 ...
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0answers
65 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
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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
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1answer
94 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
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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
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0answers
282 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
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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
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1answer
203 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:...
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1answer
901 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
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1answer
366 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 ...
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2answers
3k 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
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0answers
643 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
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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
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1answer
117 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
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0answers
984 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
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1answer
6k 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
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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 ...
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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 ...
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1answer
349 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
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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
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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
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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
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0answers
737 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-...
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0answers
209 views

SUID executable doesn't work for `/dev/mem` access

Here is explained how to gain access to the peripheral without being root. I've just tried in my environment (Raspbian Stretch, RPi2, Qt5.9) in this way: int main(int argc, char *argv[]) { ...