Can't get touch event DM3730 on Linux 2.6.37 and QT

Hi Egor,

Have you verified that your touch screen is exported to QT, when you start, just like as show bellow in your QT start up

export TSLIB_TSDEVICE=/dev/input/touchscreen0

export QWS_MOUSE_PROTO=Tslib:/dev/input/touchscreen0

Thanks,

Sreenivas

Hi, Sreenivas.

Yes, these variables are exported, but it makes no sence(

I've also tried to disable x server:

root@devkit:~# update-rc.d -f gpe-dm remove
update-rc.d: /etc/init.d/gpe-dm exists during rc.d purge (continuing)
 Removing any system startup links for gpe-dm ...
  /etc/rc0.d/K20gpe-dm
  /etc/rc1.d/K20gpe-dm
  /etc/rc2.d/S99gpe-dm
  /etc/rc5.d/S99gpe-dm
  /etc/rc6.d/K20gpe-dm

and then execute

root@devkit:~# ./qte-example -qws

I really don't know why qtButtons can't be clicked?!!

please, help!

Hi,

Please find that your Qt source code has enabled touch screen event to accept as your widget needs to have "QT::WA AcceptTouchEvents" attribute set and then graphics items should have "acceptTouchEvents" attribute to true.

You are using an evdev input, and that is not (well) supported in Qt4, refer to below:

https://bugreports.qt-project.org/browse/QTBUG-25329

You might have better success if you can use tslib.

Alternatively, you can move to Qt5 where evdev as well as Tslib are well supported.

Sreenivas Kowtharapu said:

Please find that your Qt source code has enabled touch screen event to accept as your widget needs to have "QT::WA AcceptTouchEvents" attribute set and then graphics items should have "acceptTouchEvents" attribute to true.

I'm a beginner at QT (and at Embedded systems), so I don't quite understand where should i insert it. I'm followwing Derek Molloy tutorial http://www.youtube.com/watch?v=kP7uvOu9hoQ on BeagleBOne. But I have Technexion devkit. Beaglebone linux version is 3.2.34 and mine is 2.6.37.

Here is my test program main.cpp:

#include "mainwindow.h"
#include <QApplication>
#include <QTouchEvent>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    
    return a.exec();
}

and here is mainwindow.cpp:

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_pushButton_clicked()
{
    ui->lineEdit->setText("DevKit");
}

And in Derek's tutorial it works ok. Could you tell me how I can enable qt source code to accept touch screen events?

Prabindh Sundareson said:

You are using an evdev input, and that is not (well) supported in Qt4, refer to below:

https://bugreports.qt-project.org/browse/QTBUG-25329

You might have better success if you can use tslib.

Alternatively, you can move to Qt5 where evdev as well as Tslib are well supported.

I haven't mentioned evdev anywhere, only evtest. TsLib is installed on Technexion kit. And i think i'm using it, as there is TSLIB_TSDEVICE=/dev/input/touchscreen0 in environment variables.

Any suggestions?

Is it even possible to make a QT GUI application for this dev kit with touchscreen? What I'm doing wrong?

Yes, it is possible.

Cool) And what next? any advice?

Use QT5 for your code instead of QT4, where you can use evdev input ;)

I'd like to, but my Target device has Angstrom Linux with kernel version 2.6.37, which doesn't support qt5