Dell monitor touchscreen and QT tslib

Hello there,
I have a E2014T dell touch monitor and I am trying to use it in pair with BeagleBone Black. The touch module is connected using usb cable.
I have read in this tutorial:
How to enable the tslib and touchscreen. But I think, that this reffers to a touchscreen not connected to the usb, because it doesnt work.

Without adding those variables to enviroment:
$ sudo nano /etc/environment
→ add the following lines
→ Save (Ctrl + O) and exit (Ctrl + X)
$ sudo reboot

Touchscreen works out of the box, but it is not even close to being calibrated. The offset is really big and it changes when my finger is in different part of the display. After enabling the:


Touchscreen stops working. I feel like its not event0 at all.
When I run ts_calibrate and try to press the crosshair, it doesnt work. It feels like touchscreen is off for the ts_calibrate program.

Does anyone has any expirience in such usb touchscreens and BeagleBone Black? I Would really aprichiate some help.

Which version of Qt are you using?
Debian or Angstrom On the Bone?
Is there any other event in /dev/input?

I am using debian. I cant tell the exact qt version now, as i dont have the hardware on me. I remember that there are inputa from 0 to 3 though. I tried all of them I think. The touch screen only barelly works with none of them selected and they appear only after i connect the monitor through usb... Weird.

I have just realised one thing- When I connect the monitor to the BeagleBone Black using USB, there appears 3 input entries (input0, 1 and 2). What I forgot to mention is that I had an usb dongle connected to the monitor itself, because it also server as a usb hub. In this scenarion then a USB dongle (keyboard + mouse) is connected to the USB hub in the monitor and then the monitor itself is connected to the BeagleBone Black. I wil have to check what input number is the touchscreen exacly when i get the hardware again. But even though- I tried to use all of them in /etc/enviroment

W dniu piątek, 6 marca 2015 20:07:47 UTC+1 użytkownik James S napisał:

Hello there,
I am using QT 4.8.6.

this is the de/input/ dir without any additional peripherals connected:
root@beaglebone:/dev/input# ls
by-id by-path event0 event1 mice mouse0

I have managed to calibrate the screen, the proper device was event1 as i checked through expirience. But even though the screen was calibrated, my QT application still has the same offset. Its like the calibration didnt have any effect. Do you know maybe what else can I check?

W dniu piątek, 6 marca 2015 20:07:47 UTC+1 użytkownik James S napisał: