India

I'd say the code related to I2C. Do you have any other processes that are consuming files on your target ?

@sgaist thanks . I upgraded jessie to stretch, then to buster. The Qt Creator version remains same, which has sorted my problem

@shubham-singh-rao said in Qt Source code of Jessie Image not working in Buster Image?: Why its not running basic libraries of Qt in buster? Did you installed all needed parts of Qt on buster? Also, if you have copied the build directory delete it, run qmake and rebuild.

thanks a lot for your respond@Pradeep-Kumar i have solved that error .i.e. just by copying that libraries to my path /usr/local/Trolltech/QtEmbeddedQtEmbedded-4.8.6-arm/lib and build it successfully!!!!!

@tomasz3dk This should be the correct and accepted answer :)

@Sivamani-V said in How to connect to mysql server in ubuntu 16.04?.: QMYSQL Driver not loaded. Available drivers: QMYSQL QSQLITE QMYSQL3 This gets asked so many times, here & elsewhere. Googling for your message will bring up many hits. Under Linux/Ubuntu it's usually libmysqlclient or libqt5sql5-mysql or similar which is missing/has dependencies missing/wrong version.

@SHUBHAM-SINGH-RAO you need to be more specific. But I can say with a high certainty that you're doing stuff wrong, or at the very least not what you want to do. What is transferred via serial port? Is it ascii characters representing hex values or can it be any arbitrary byte ?

@SHUBHAM-SINGH-RAO said in Unable to fetch complete data using [ int serialDataAvail (int fd)]: I am using wiring pi library for serial communication Well, this is a Qt forum, only few people will know about wiring pi here. You should get better answers in a Raspberry/Wiring Pi forum. That said, why don't you use QtSerialPort?

Code can be improved for performance. But if you are fine then it's good. Because this for sure, will call MainWindow::on_pushButton_clicked() a lot of time. Edit: Also if it works can you mark it as SOLVED.

@Maaz-Momin https://forum.qt.io/topic/97741/query-related-to-waiting-timer-class

@SHUBHAM-SINGH-RAO said in How to use QTimer in Qt Creator to get data from an external peripheral device for a specific time interval only?: timer.start(10000); manager->get(QNetworkRequest(QUrl("http://www.google.com"))); loop.exec(); Don't do this! Local event loops are advanced stuff, and can easily lead to problems. Use QNetworkRequest as it is designed with signals&slots. In your timeout slot, you can close() or abort() the QNetworkReply, like described here: https://stackoverflow.com/questions/14535502/how-to-stop-qnetworkaccessmanager-from-getting-a-reply-c

Welcome! @aavi said in Qt 5: why we use this in ui header in qt? The short answer is this: The UI files make it easy to automatically generate C++ code for your GUI. I believe @SGaist is talking about the chapter at http://doc.qt.io/qt-5/designer-using-a-ui-file.html

Hi and welcome to devnet, @Pradeep-Kumar might know something about that. You can also take a look at the Online Communities wiki page. Hope it helps

Keyboard and mouse (or touch screen) are not the same. So which one are you currently using and what is you exact goal ?

One more question: are you using Qt 4 by any chance?

Exactly. There is no use of the friend function over here

Hi, You don't connect classes, you connect instances of them. You have all the details in the Signals And Slots chapter of Qt's documentation.