Questions tagged [qt]
a cross-platform application framework for developing application software
2
votes
1answer
28 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
17 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
20 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
35 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
94 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
39 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
41 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
0answers
60 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
33 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
634 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
62 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
817 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
168 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
votes
1answer
1k 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
106 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
495 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
187 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
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 ...
1
vote
0answers
566 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
690 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
73 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
589 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, ...
2
votes
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
votes
0answers
831 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
votes
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 ...
-1
votes
1answer
30 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
168 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
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 ...
1
vote
1answer
669 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
790 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
643 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
vote
0answers
160 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
votes
1answer
323 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
vote
0answers
65 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
11k 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 ...
2
votes
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
394 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 ...
3
votes
4answers
25k 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
vote
0answers
208 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 ...
8
votes
2answers
22k 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
545 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
votes
0answers
134 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
votes
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
votes
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
votes
0answers
456 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
11k 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 ...
6
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 ...
