30 votes
Accepted

Turning 'tvservice' on and off leaves screen blank

tvservice is not the best to turn off and on the screen. Much better way to do this (found after a day of searching) is using vcgencmd command (more on this here). vcgencmd display_power 0 turns off ...
lewiatan's user avatar
  • 713
13 votes
Accepted

PyQt5 on a Raspberry Pi

OK... I managed to get this to work. This is what I did. QT Core needs to be installed with sudo apt-get install qt5-default You'll need to copy over sip and PyQt5 to your Raspberry Pi (I used SFTP)...
CharlieHorse's user avatar
11 votes

PyQt5 on a Raspberry Pi

In Raspbian Stretch Lite the following worked for me: sudo apt-get update sudo apt-get install qt5-default pyqt5-dev pyqt5-dev-tools
Zeh's user avatar
  • 211
10 votes
Accepted

Qt applications don't work due to libEGL

It's a usual linux and Unix problem, nothing Pi-related. Here is the problem: your libs need to be symlinked. Do sudo -s and become a root for such an operation. And let's troubleshoot it! First, ...
Alexey Vesnin's user avatar
5 votes
Accepted

ImportError: No module named 'PyQt5'

Generally a good idea is to do a search on the Pi. apt-cache search pyqt5 Perhaps the command you need is sudo apt-get install python3-pyqt5 I suggest you always preferentially use apt-get rather ...
joan's user avatar
  • 71k
5 votes

Installing Qt on Raspberry Pi 3

Here is a working way to install Qt5. For Qt5 there is no need for dev-tools. So this command is not relevant: sudo apt-get install qt4-dev-tools The two commands needed to install Qt5 fully are: ...
Chandra's user avatar
  • 51
3 votes

PyQt5 on a Raspberry Pi

I can't leave a comment, not enough reputation, but thought I should mention this in case it helps anyone using VirtualEnv: In my case (Raspbian on a Raspberry Pi 3, Python 3 in a virtual environment)...
Moustache's user avatar
  • 131
3 votes

PyQt5 on a Raspberry Pi

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-qt4 So in your case ...
Yatish Prasad's user avatar
3 votes

Run Qt Application on Startup

I guess you are using Raspbian Stretch. This comes with systemd so you should start your qt project as service. First create a new service: rpi3 ~$ sudo systemctl edit --force --full my_qt_project....
Ingo's user avatar
  • 42.1k
2 votes

Which toolchain for Raspberry Pi 3 and Qt5

I'm going through the same thing. You need to use the 4.9.2 compiler: Look under arm-bcm2708 for the arm-rpi-4.9.3-linux-gnueabihf folder. I still haven't been able to cross-compile QT for Pi3, but ...
dayres's user avatar
  • 21
2 votes

Qt applications don't work due to libEGL

In my case this fixed the issue sudo ln -s /usr/lib/arm-linux-gnueabihf/libGLESv2.so.2 /usr/lib/arm-linux-gnueabihf/libGLESv2.so
Noufal's user avatar
  • 21
2 votes
Accepted

How to get qt4 runtime libraries

sudo apt-get install libqtgui4 worked for me. HTH
Flaschengeist's user avatar
2 votes
Accepted

Installing Qt on Raspberry Pi 3

Not particularly sure why you are trying to install that package, the App Note for installing Qt Creator on Raspberry Pi says to install sudo apt-get install qt4-dev-tools and sudo apt-get install ...
pfl's user avatar
  • 341
2 votes
Accepted

Qt Application crashing on Raspberry Pi 3 with Adafruit 2.8" PiTfT touchscreen

I found a way to avoid the crash: Compiling Qt with libinput support and using libinput instead of evdev.
maxwell's user avatar
  • 133
2 votes

Access RPi's camera stream in OpenCV C++ (Qt)

I found the answer here. Turns out the best scenario was available. OpenCV has a method for acquiring mjpeg streams. Perfect! Here is the same code, adapted to my setup: #include <stdio.h> #...
A. Vieira's user avatar
  • 141
2 votes

How do I build Qt's mysql-plugin on Raspbian Buster

I found a solution although this is not the straightforward way to compile all at once. First I compiled and installed Qt 5.12.4 without the MySQL driver plugin as described in the tutorial ...
elnacho's user avatar
  • 43
2 votes

installing qt on raspberry pi 4

I update Raspbian Buster and the problem was solved. From the original Author.
MatsK's user avatar
  • 2,791
2 votes

Updating text file with sensor datas from three different threads

Maybe a Queue could work for you? Link. Queues are FirstInFirstOut so you could have your threads putting stuff in it and then have, I don't know, a fourth thread that will be grabbing stuff from the ...
papatrexas's user avatar
2 votes
Accepted

autostart application on raspberry pi 4 (systemd)

You created a configuration which is impossible to resolve: application_one.service must start after graphical.target (G before A) graphical.target requires multi-user.target (M before G) multi-user....
Dmitry Grigoryev's user avatar
2 votes
Accepted

install qtcreator kit on raspberry pi 4b - 64 bit

The qtcreator package from apt only installs Qt Creator without any Qt installation. To use Qt Creator for development on Raspberry Pi, you must install Qt separately. I found this guide that explains ...
uraihan's user avatar
  • 46
1 vote

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

The important stuff happens in step 6 of the sysprogs tutorial: There the libraries and headers of your Raspberry Pi get synced over to your Windows PC. However, it looks like some required -dev ...
Matthias Lüscher's user avatar
1 vote

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

To start a script or program in the desktop as a normal user (not as root), you can make a desktop file in the ~/.config/autostart folder: Adafruit: adding vncserver autostart
Jot's user avatar
  • 123
1 vote

PyQt5 on a Raspberry Pi

You can try steps mentioned below. It will take some time to make and make install. Please be patient. sudo apt-get install qt5-default wget https://www.riverbankcomputing.com/static/Downloads/sip/4....
Raj's user avatar
  • 11
1 vote
Accepted

Variables dont get initialized

This is a general Python question, not specific to the Raspberry Pi. When using class variables within class functions in Python you need to use self. So for x in range(self.step_count*2): and GPIO....
joan's user avatar
  • 71k
1 vote

How can I move my normal c++ main() function code to qt main function?

you can add test_encoder.cpp in mainwindow.cpp and should create a pointer of class in mainwindow.h like this: #ifndef MAINWINDOW_H #define MAINWINDOW_H #include <rotary_encoder.h> #include <...
isan's user avatar
  • 19
1 vote
Accepted

Jessie: libEGL warning: DRI2: failed to authenticate

As far as I know now, these issues are unrelated. After some serious debugging of code I was reusing for the data acquisition, I noticed that there were some problems with process spawning that was ...
bearoplane's user avatar
1 vote
Accepted

Disable default bluetooth dialog box for accept pairing in raspberry pi3

As in the discussion in the comments, the pop up is associated with the default blue-man application in Raspberry Pi. Just right click on the BT icon in the tray and remove and your default ...
Mahesh Mohandasan's user avatar
1 vote

Raspbian or Raspbian Lite for Cross Compiling Qt

If you intend to run Qt without X11 Raspbian Lite is perfect. If you intend to run on X11 then you're probably better off using Raspbian.
Luca Carlon's user avatar
1 vote
Accepted

Host errors after cross-compilation of Qt 5.9.2

Looks like you resolved the problem by upgrading and doing a clean build? This Qt 5.9 bug sounds strikingly similar and appeared to affect all cross-compilation targets including Raspberry Pi. ...
jdonald's user avatar
  • 2,904
1 vote

QT segmentation fault when using BCM2835 for SPI

I had the same problem and I discovered that was my fault, I mean you have to check the return value of a function and manage it in case of error. In this case the function bcm2835_spi_begin(); ...
omotto's user avatar
  • 111

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