@J-Hilk said in Serial terminal disconnecting unexpectedly: of course not, and there is no guarantee that 20ms will be enough each and every time! If new data arrives readyread will signal again. Your job as a programmer is to store the data, identify if all is arrived, and only then do your processing. Thank you so much for your quick reply. I store the data in an array and wait for the entire data to come. Now there is no problem with serial communication.

Thanks, @kuzulis for giving me a reference to look at the device side. The problem is solved by adding line coding settings to the CDC buffer on the STM. It is related to the hardware. STM users should bind USBD_CDC_LineCodingTypeDef data structure to CDC_Control_FS function. In ready-made examples, this binding does not exist. Users who do not add this binding can face the same problem in long term tests. Maybe it can help people who face the same problem. Regards

To be continued at bugreports.qt.io https://bugreports.qt.io/browse/QTBUG-73965

@douglas Take a look at http://doc.qt.io/qt-5/linux-deployment.html And the question is: which version do you actually want to use?

Solved. The missing libQt5SerialPort.so.5 error on the target device was because that library effectively was not present. On the host side I added that library in the package list of the image and rebuild the image itself.

I am able to compile the project with serialport now after reinstalling qt5 > sudo apt-get install qt5-default But I've got different error now which I think is a different issue altogether. Unable to query physical screen size, defaulting to 100 dpi. To override, set QT_QPA_EGLFS_PHYSICAL_WIDTH and QT_QPA_EGLFS_PHYSICAL_HEIGHT (in millimeters). QOpenGLShaderProgram: could not create shader program QOpenGLShader: could not create shader Could not link shader program: "" QOpenGLShaderProgram: could not create shader program QOpenGLShader: could not create shader QOpenGLShaderProgram::uniformLocation( texture ): shader program is not linked

Thanks! It worked!

Probably it is a bug of QWinOverlappedIoNotifier : https://bugreports.qt.io/browse/QTBUG-48653 Let's wait for more info about..

AWESEOME! Thank you very much. 2) did the trick. I found a file /var/lock/LCK..ttyS3. After removing it the code posted above works fine. I will now try 1) or implement a patch myself. Thanks a lot. You made my day. Phillip

You're welcome ! Since you have it working now, please update the thread title prepending [solved] so other forums users may know a solution has been found :)

Ok, following the wiki worked.

Workaround: Start an application (QProcess) that pipes the serialport to a localhost socket.

@Leonardo said: nections, the parameters must be of types that are known to Qt's meta-object system, because Qt needs to copy the arguments to store them in an event behind the scenes. ... Call qRegisterMetaType() to register the data type before you establish the connectio Wow, that really helps! Thank you so much! I will try it right now

@koahnig Not really sure though.... But the problem was solved as soon as I installed Qt Creator from Software Centre, while keeping the libraries for QtSerialPort from .run file downloaded from the website. I really guess that this is about the 64-bit and 32-bit version problem. Thank you very much for your attention! :D Regards, Gen

@Digits Hi He has not been online for 2 years so its unlike he return to answer this. Maybe you can use this https://github.com/QkThings/qkloader IT implements XMODEM in a more cpp friendly way using QSerialPort