Beaglebone Black and Qt 4.8.6



  • Hi guys,
    I'm trying since several days to get a acceptable GUI on my Beaglebone Black. I want to read accelerometer values via CAN bus and visualize them by a rotating disc or something like this (loaded via pixmap). I added this Pixmap to my scene and the scene to my GraphicsView.
    Unfortunately, especially when the disc rotates fast, there is some ugly flickering and fragmenting. Since GraphicsView should use double buffering inherently, I think there isn't much else I can do than trying to set an OpenGL viewport. But the Beaglebone Black doesn't support SGX/OpenGL ES with kernel v3.8, and with kernel 3.12 (from Robert C. Nelson) I don't get the EGL surface initialized with Qt 4 (Qt 5.1.1 works, but this isn't an option).

    So I hope you could help me with this problem. Maybe it isn't even neccessary to use OpenGL for better rotating (hacks are welcome ;-))?

    At last a quick summary of my text:

    • Beaglebone Black, Kernel v3.8 (due to better cape support)
    • Qt 4.8.6 (due to better embedded support, more than just window, etc.)
    • Fast / flickerfree rotation of Pixmaps
    • Either with SGX / OGLES or without (enable better buffering, or another tricks)

    Many many thanks in advance!

    Regards,
    Marcel

    Edit:
    I should say that I'm using Ubuntu 14.04 with a Linaro Toolchain for crosscompiling.



  • Hi, sorry for double post, but now I got the graphic drivers (SGX) running under kernel v3.8 - the demos (OGLES2EvilSkull, etc.) are running.

    Unfortunately Qt 4.8.6 still doesn't work. I've added these to patches https://github.com/prabindh/qt-configs/tree/master/qt4.8 first, and then this one: http://downloads.ti.com/dsps/dsps_public_sw/gfxsdk/4_10_00_01/exports/0001-Qt-4.x-patch-for-1.10DDK.patch

    Now, if I want to run an example application, it quits with error 0x3001:
    debian@beaglebone:~/hellogl_es2$ ./hellogl_es2 -qws -display powervr
    QEglContext::createSurface(): Unable to create EGL surface, error = 0x3001

    The Qt application opens up, but the OpenGL area remains green.

    Do you have any ideas? libpvrQWSWSEGL.so is configured as WindowSystem.

    Regards,
    Marcel


  • Moderators

    sorry i can't help you with your initial problem.
    But just out of curiosity: what is your hardware setup for reading the CAN data. Can you also share some code?


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