Qt-embedded Touch screen problem on IMX53 (SABRE tablet)

[winstonrodrigue]

Dear All,

        I have been working on a project based on  QT-embedded on linux on imx53 sabre platform.

• So far  i have installed qt-embedded on target,
• installed Qt cross compiler on host
• compiled an app which runs on imx53.

But the problem is qt app does not recognize the touch.... But the touch screen driver is installed

I verified it by doing

export TSLIB_TSDEVICE=/dev/input/ts0

export TSLIB_CALIBFILE=/etc/pointercal

export TSLIB_CONFFILE=/usr/etc/ts.conf

cat /dev/innput/event2 | hexdump

When i do that and touch the screen i get the hex output..... So touch screen is detected by linux.

I have configured the qt-embedded as following.....

./configure -embedded arm -xplatform linux-mxc-g++ -release -prefix /usr/local/Trolltech/Qt-4.6.0/ -no-opengl -glib -qt-gfx-linuxfb -qt-kbd-tty -qt-kbd-linuxinput -qt-mouse-linuxinput -qt-mouse-tslib -little-endian -qt-gfx-linuxfb -host-little-endian -v -opensource -confirm-license -force-pkg-config -no-phonon

so tslib is included.

so how can i make my application get the touch input.. ??

     Thanks and regards,

   Winston Rodrigues,

   Schiller Healthcare

   Bangalore

[LeonardoSandova · Accepted solution]

Hi Winston,

It may be the case that the GUI does not know how to interpret the touches. Can you check if the touchscreen driver can be configured/compiled to support SINGLE TOUCH?

Also, Freescale is working on YOCTO, the next BSP builder so I strongly suggest you to try it. It has QT, and the only thing you may  need to do is to add a recipe with your custom application. Please take a look at his page to start using it.

i.MX Yocto FAQ

[winstonrodrigue]

Dear Leonardo...

           I dont know exactly how to enable single touch support...

And YOCTO is replacement for LTIB ?

Where can i download the source ?

   Thanks,.,.

  Winston

[Yuri]

The enclosed general considerations may be helpful

[winstonrodrigue]

Dear Yuri Muhin,

     I have successfully compiled tslib. and I have set the

environmental variables properly. when I run ./ts_calibrate I can see

"TSLIB calibration Utility" screen on my board. and one crosshair on

top left corner. But when i touch it Nothing happens.

   I tried to do a little debugging by using printf statements in

ts_calibrate.c file just to know where exactly is the problem. It gets

struck in the function getxy();

   when i see the code of  getxy() in tests/testutils.c , it gets

struck at this point :

    do {

              printf("Inside do-getxy\n");

                 if (ts_read_raw(ts, &samp[0], 1) < 0) {

                      printf("Inside if-getxy\n");

                         perror("ts_read");

                         close_framebuffer ();

                         exit(1);

                 }

         } while (samp[0].pressure == 0);

  here it never comes out of the do-while loop. so i guess there is a

problem in ts_read_raw() function.

  when i run ./ts_print_raw it gives me:

root@freescale /mnt/buha/bin$ ./ts_print_raw

14224.983211:  22304  24288      0

14224.987890:  22304  24288      0

14224.992615:  22304  24288      0

14224.997350:  22304  24288      0

14225.002073:  22304  24288      0

14225.006804:  22304  24288      0

14225.011538:  22304  24288      0

14225.016271:  22304  24288      0

14225.020993:  22336  24272      0

14225.042071:  22432  24272      0

14225.043366:  22432  24272      0

14226.641742:  22544  23968      0

14226.646461:  22544  23968      0

14226.651188:  22544  23968      0

14226.655925:  22544  23968      0

14226.660646:  22544  23968      0

14226.665375:  22544  23968      0

  So i guess there is no problem with the touch screen driver.

It uses egalax capacitive touch screen.

    Thanks and Regards,

   Winston Rodrigues,