Touch Screen Calibration

Hello everyone,
We are having trouble with sensitivity and calibration on the touch panel.

It triggers a release event when we click on a specific point and move our finger without lifting it. It makes a big problem when we have to press two button together.

In addition, even when touching hard at any point, it receives as other pixels are touching. It says multiple points are pressed.

Touch event comes from cat /dev/input/event2 doesnt come from cat /dev/input/touchscreen0. Shouldn’t the Touch commands come from there?

Could you help about to solve this problem?
Thank you for your help.

Dear @sevginurb

Do you use EGLFS on top of Qt? And do you use Qt touch events? Unfortunately, I think it is not possible to calibrate the touchscreen. That the events don’t come from /dev/input/touchscreen0 is expected it would be used if a restive touch is used.

Regards,
Stefan

We have the same problem with the iMX8. We checked with two different Touchscreen from different manufacturers. Same problem: the touch point is about 1cm off.
Any solution to this?

Hello @MikesCo

If it’s only an offset you might be able to do just regular touchscreen calibration:
https://developer.toradex.com/knowledge-base/touch-screen-calibration-torizon

However, normally capacitive touch screen should normally already be pre-calibrated by the manufacturer. Can you maybe try to contact them and ask if they have production issues?

Regards,
Stefan