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

[sanjeet]

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

[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 :

configure Qt with -qt-mouse-linuxinput option and rebuild
find the device corresponding to my touch screen : on my board it was /dev/input/event1.
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.

[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 :

configure Qt with -qt-mouse-linuxinput option and rebuild
find the device corresponding to my touch screen : on my board it was /dev/input/event1.
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

[webquinty]

Hello,

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

Best regards.