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Questions tagged [qt]

a cross-platform application framework for developing application software

0
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0answers
37 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
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0answers
21 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
383 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
59 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
690 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-...
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0answers
81 views

Qt project deployment on rpi 3 board

I am done with cross compiling Qt 5.10.1 for rpi 3 board and took me nearly 7-8 days. now everything is set and when i tried to run the deployed project on rpi3 : The error popped out: relocation ...
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0answers
143 views

cross compilation Qt 5.9.1 with rpi 3

I am trying to cross compile QT 5.9.1 for Rpi3 board. when i run make command i am getting following errors: make[5]: *** [../../../../lib/libQt5EglFSDeviceIntegration.so.5.9.1] Error 1 make[5]: ...
0
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0answers
134 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 ...
0
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1answer
780 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
89 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
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1answer
382 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
157 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
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2answers
2k 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 ...
0
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0answers
364 views

Gstreamer error qt / opencv project

After making project on Rpi I receive this error after calling VideoCapture c(0) (I think...) Am I referencing the Pi NoIR camera incorrectly? Or am I missing or have I incorrectly installed ...
1
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0answers
531 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
583 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
71 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.
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0answers
527 views

PyQt support for WebEngine on Pi

I have installed PyQt5 for Python3 as per the solution here. However while I can import various modules into Python I am finding that none of the WebEngine modules import (WebEngine, WebEngineWidgets, ...
1
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1answer
3k 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 ...
0
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0answers
802 views

Qt 5.9 cross-compilation guide for Raspberry Pi

G'day, I've been attempting to setup a cross-compile workflow for the last week, and have not had any success, despite the numerous guides and how-to's online. My host machine is running 64-bit ...
0
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2answers
1k 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
29 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
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1answer
137 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 ...
0
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2answers
4k 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 ...
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0answers
656 views

PyQt5 on Raspberry Pi 2 Model B

After viewing the answer here I decided to ask the same question two years later: how can I install PyQt5 on a Raspberry Pi 2 Model B? I also followed a few other threads (like this one) which ...
1
vote
1answer
578 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
734 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
625 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-...
1
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0answers
147 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[]) { ...
0
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0answers
389 views

qcamera does not get to active state in raspberry pi 3 - no frames being detected

I am trying to get the picam on raspberry pi (ubuntu mate 16.04) to show a live preview in a qt app window. As a reference, I am able to get an example code working in windows 10. On win10 the ...
0
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1answer
290 views

Raspian or Raspian Lite for Cross Compiling Qt

I try to follow this guide https://wiki.qt.io/RaspberryPi2EGLFS for cross-compiling Qt. The instructions don't specify whether I need to use the Desktop version or whether also the lite version would ...
1
vote
1answer
2k views

Host errors after cross-compilation of Qt 5.9.2

I've cross-compiled Qt 5.9.2 for Raspbian Stretch with the following setup: git clone -b 5.9 git://code.qt.io/qt/qt5.git cd qt5 ./init-repository ./configure -release -opengl es2 -device linux-rasp-...
1
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0answers
58 views

How to use RF24Mesh on Raspbian in Qt

I want to use the RF24Mesh library in my QT application in Raspbian Jessie. I can compile the example and run it (with the make command) but when I include libs to my QT app, it gives the error: ...
3
votes
2answers
10k views

Installing Qt on Raspberry Pi 3

I'm trying to install Qt Creator to my Raspberry Pi 3 for a GUI project. However when I use the command sudo apt-get install qt5-default it gives an error saying that: E:Unable to fetch some ...
0
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1answer
1k views

Cross compiling Qt on windows for raspberry pi, missing xcb dependencies

I am trying to start with Qt for Raspberry Pi on a Windows Dev System. To begin with to setup the environment, I followed the below as per the official wiki page. From starting at various stages, I ...
1
vote
1answer
355 views

Difference between executing script from terminal vs /etc/rc.local

I am booting my raspberry Pi to Terminal at the moment. I have a script that I would like to run. The script looks like this run_gui.sh: python /home/pi/1.py & /home/pi/Gui& If I SSH into ...
1
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4answers
22k views

PyQt5 on a Raspberry Pi

I have a Raspberry Pi 3 with Raspbian installed, along with a 7" touch screen. I'm in the process of creating an application in Python to read several DS18B20 Thermocouples to monitor the temperature ...
1
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0answers
193 views

Cross compiling QT and example program does not find platform

I followed the follwoing guide to cross-compile QT 5.6 on a Ubuntu 16.04 machine for the raspberrypi2 running jessie: https://wiki.qt.io/RaspberryPi2EGLFS#A_modern_guide_for_cross-compiling_Qt_5....
2
votes
0answers
2k views

Live Camera App with Qt

I am trying to write an application using Qt that displays live video from the Pi camera. The Qt example projects "camera" (using QWidgets) and "declarative-camera" (using QML) both run without ...
7
votes
2answers
19k views

Qt applications don't work due to libEGL

I am developing some (simple) GUI applications for the RPi2 in Qt5. The setup: The code development is performed on a Windows laptop using Netbeans + Qt Designer and remotely built on the RPi running ...
0
votes
1answer
512 views

QT build error: “WARNING: TARGET is empty” and “make: nothing to be done for ”first“”

I recently installed qt5 on Raspbian. I'm trying to compile this package so I ranqmake && make. I get these errors: WARNING: TARGET is empty make: nothing to be done for 'first' Before ...
0
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0answers
131 views

Control kodi from stdin

I wonder if it possible to send characters to the stdin of kodi (i.e. using Qt QProcess::write() to simulate a keyboard. I did the same with other applications - like omxplayer - and it worked. But ...
0
votes
1answer
1k views

QT segmentation fault when using BCM2835 for SPI

I am a novice when it comes to programming. I am attempting to set up SPI communication between a module and my RPI3. The following is my main.cpp code (I plan to neaten up the code once it works) #...
0
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1answer
4k views

Run Qt Application on Raspberry Pi 3

I'm very new to Qt. I want to start developing GUI Qt application in C++ on raspberry pi. I want to start this application in Kiosk mode on boot. I manage to do it, but I encounter the following ...
0
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2answers
5k views

wiringPiSetup: Must be root (Did you forget sudo ?)

I have a problem when I click run it shows this error wiringPiSetup: Must be root (Did you forget sudo ?) I also try to write this on terminal sudo qtcreator to open the qtcreator as sudo but ...
3
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0answers
431 views

QML without X11

Is it possible to run QML files without X_Desktop environment in raspbian Jessie for Raspberry Pi3? I found this tutorial: EGLFS , but I would prefer if it is possible to compile directly on RPi, ...
5
votes
1answer
10k views

Turning 'tvservice' on and off leaves screen blank

I'm running the Qt5 application on my raspberry pi and I would like to introduce some kind of a power-saving feature. I don't use x11 or wayland, because I don't need it, but I use gles2 (OpenGL for ...
7
votes
3answers
7k views

Which toolchain for Raspberry Pi 3 and Qt5

Which is the recommended toolchain to cross-compile Qt5.6 for Raspberry Pi 3? I tried official tools: https://github.com/raspberrypi/tools but it seems they don't support the architecture and flag ...
0
votes
2answers
4k views

Compile and run Qt5 webengine on rpi2/3

I have followed the tuto here : https://wiki.qt.io/RaspberryPi2EGLFS to cross-compile Qt 5.6 for my pi 2. But I did not used the git repo, I have downloaded the source tarball. I checked by running ...
0
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1answer
317 views

undefined reference to QCamera constructor

I'm writing a simple camera project for Raspberry Pi, via cross compiler visual studio. step 1: I created a qt project using visual studio step 2: coding for project When coding for project, I ...