How can i calibrate touch screen for ARM based iMX25(freescale) board on Linux

Hi,

I have configured Qt-4.7.3 for ARM based iMX(from freescale) target board under Linux 2.6.31
On my host PC there is fedora-14.
I have deployed Qt library and ts library to board(/usr/lib directory). All the environments variable
i have exported.
I am able to run my application( or touch example provided by Qt) on board, even touch screen responding, but touch screen event not responding in proper way.
If i am touching(or pressing or moving) the screen, corresponding event occurs somewhere else in touch screen area. That means, suppose that i have to do action on top left area then this event
occurs by touching the bottom right area or somewhere else. And also i am not able to close, maximize or minimize the application by pressing(touching) the corresponding button on dialog(top right corner on dialog or main window).
Whereas i have analyze this is the calibration problem. Is it calibration problem ?
If it's calibration problem then how can i calibrate ???

Or, what else the problem ? Can you suggest me any solution ?

Regards,
Sanjeet

Have you look to http://doc.qt.nokia.com/4.7-snapshot/qws-mousecalibration.html. I use this example to calibrate my touch screen and it works fine.

But if calibration doesn't work, maybe you have a problem with the touch screen or better with the qt driver you use. I had some problems to use my touch screen too, calibration doesn't seem to work, cursor move in a very strange way with an error in position not linear and not really predictive. I realized I was using the default driver for pointing device which simply not work with my device.

I have to follow those steps to make it works :

1. configure Qt with -qt-mouse-linuxinput option and rebuild
2. find the device corresponding to my touch screen : on my board it was /dev/input/event1.
3. export QWS_MOUSE_PROTO=LinuxInput:/dev/input/event1 on my board before running the QWSServer.

After that my touch screen works fine.
Hope it can solve your problem too.

Quote:

---

Originally Posted by nix

Have you look to http://doc.qt.nokia.com/4.7-snapshot/qws-mousecalibration.html. I use this example to calibrate my touch screen and it works fine.

But if calibration doesn't work, maybe you have a problem with the touch screen or better with the qt driver you use. I had some problems to use my touch screen too, calibration doesn't seem to work, cursor move in a very strange way with an error in position not linear and not really predictive. I realized I was using the default driver for pointing device which simply not work with my device.

I have to follow those steps to make it works :

1. configure Qt with -qt-mouse-linuxinput option and rebuild
2. find the device corresponding to my touch screen : on my board it was /dev/input/event1.
3. export QWS_MOUSE_PROTO=LinuxInput:/dev/input/event1 on my board before running the QWSServer.

After that my touch screen works fine.
Hope it can solve your problem too.

---

Hi nix,

Thanks first of all for suggesting me.

I have sort out the problem, now my touch screen working properly.
Actually it's was calibration problem, i was not calibrating in proper way.
I have done google-search got idea for calibration.

Thanks & Regards,
Sanjeet

Hello,

there is an example in qt sources how to make a calibration.

Best regards.