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    Touch screen problem with 15,6" size

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    • M
      miki81 last edited by

      Hello,
      I use Raspberry Pi and I have problem with touch screen:

      First time I bought 14" touch screen from chalk-elec ("http://www.chalk-elec.com/?page_id=1283#!/14-HDMI-interface-LCD-with-capacitive-touchscreen/p/36248806/category=3094861":http://www.chalk-elec.com/?page_id=1283#!/14-HDMI-interface-LCD-with-capacitive-touchscreen/p/36248806/category=3094861). I connected it to Raspberry, run QML application and everything was perfect (without callibration, drivers, tslib plugins etc). Then I bought simple 15,6" LED screen and vandal proof touchpanel from CJTouch (exacly this one: "http://www.cjtouch.com/product-show.asp?id=688":http://www.cjtouch.com/product-show.asp?id=688). I calibrated touchpanel in xinput_calibrator application and in X11 server everything works perfect but I have problem with my QML application. The maximum cursor position in X dirrection is about 10 inch and Y maximym position is about 5.18 inch (25,5cm x 13cm) - the touchpanel is 13,58x7,67 inch (34,5x19,5cm). When I slide finger, cursor smoothly moves to the right, left top and down but in limited dimension. What should I do to make everything worked fine? In this forum I read about tslib, it is necessary? Why I did not have to use this plugin to 14" touch screen? I would be grateful for any suggestion

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      • SGaist
        SGaist Lifetime Qt Champion last edited by

        Hi and welcome to devnet,

        It depends on how your touchscreen identifies itself, some of them simply connect connects as mouse input.

        When you are saying you have a problem with your QML application, do you mean as a standalone application without X11 running ?

        Interested in AI ? www.idiap.ch
        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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        • M
          miki81 last edited by

          hi, thanks for reply.
          The 14" touch screen have USB cable directly from LVDS connector. The 15.6" touch panel have a box with USB cable. When I connect the 15.6" I have /dev/input/event2 and /dev/input/mouse0 device
          @
          I: Bus=0003 Vendor=24b8 Product=0001 Version=0110
          N: Name="HID 24b8:0001"
          P: Phys=usb-bcm2708_usb-1.3.2/input0
          S: Sysfs=/devices/platform/bcm2708_usb/usb1/1-1/1-1.3/1-1.3.2/1-1.3.2:1.0/input/input2
          U: Uniq=
          H: Handlers=mouse0 js0 event2
          B: PROP=0
          B: EV=1b
          B: KEY=70000 0 0 0 0 0 0 0 0
          B: ABS=100 3
          B: MSC=10
          @

          Yes I running my QML application without X11 server.

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          • SGaist
            SGaist Lifetime Qt Champion last edited by

            Did you check that your application has the same size as the touchscreen ? I mean pixel size

            Interested in AI ? www.idiap.ch
            Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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            • M
              miki81 last edited by

              I solved my problem by the weekend by another method. I reinstall Qt with tslib, calibrate screen by ts_calibrate on my raspberry and run aplication with "-plugin Tslib:/dev/input/event2" parameter. Works OK.

              Now I wondering how to hide mouse cursor :)

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              • F
                FreddeB last edited by

                Hi,

                You hide the cursor easily by setting the environment variable like..

                export QT_QPA_EGLFS_HIDECURSOR=1

                Regards
                Fredrik

                Regards
                Fredrik

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