Inaccurate touchscreen coordinates

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Inaccurate touchscreen coordinates

1,067 Views
Jamier
Contributor III

I've got a system built with Yocto Kirkstone using a 720x1280 display with a focaltouch capacitive display. The display is driven using the weston-imx layer. The display is portrait native, and we are rotating it 90deg in the weston.ini file

I find the touching near the edges gives inaccurate coordinates. I took some measurements of position and found that the touch points on x axis are linearly displaced as if there is a calibration error. (slope 0.7, offset -103)

I am certain the device try defines the focaltech display coordinates correctly:

focaltech,display-coords =  <0 0 720 1280>;

 

I wanted to see if the weston-touch-calibrator could be used to fix this, but it appears it is not included in my build, and it isn't obvious how to include it.

Does anyone have some tips on how to either investigate/fix the inaccuracy or include weston-touch-calibrator in the build? 

I've attached dmesg in case that helps.

Thanks.

 

 

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Jamier
Contributor III

In working with the touch panel manufacturer, Leadtek, it appears to be a firmware problem with the touch controller. They've made a change that  helps the accuracy when in non-native landscape mode. Still testing but so far it's helped.

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912 Views
Jamier
Contributor III

In working with the touch panel manufacturer, Leadtek it appears to be a firmware problem with the touch controller. They've made a change that appears to help the accuracy when in non-native landscape mode. Still testing but so far it's helped.

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Jamier
Contributor III

We are using a custom board based on imx8mm and a custom BSP based on Yocto Kirkstone.

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Rita_Wang
NXP TechSupport
NXP TechSupport

When your system boot up, you can go to the /dev/input directory to see if there is event exist , to see if the touch screen have the interrupt or not.

 

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Rita_Wang
NXP TechSupport
NXP TechSupport

Which board and which version BSP are you using?

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