Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. Mobile and Embedded
  4. Qt executables run without error, but nothing displays
Forum Updated to NodeBB v4.3 + New Features

Qt executables run without error, but nothing displays

Scheduled Pinned Locked Moved Mobile and Embedded
zynqzedboardubuntu 14.04qt 4.7.3vmwarehello worldcross compilearmxilinxlibraries
12 Posts 2 Posters 6.7k Views 2 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • S SGaist
    1 Sept 2015, 19:50

    Hi and welcome to devnet,

    Did you try starting your application from the command line ? That might give you some additional clues about what is happening.

    Hope it helps

    J Offline
    J Offline
    jkern
    wrote on 1 Sept 2015, 19:54 last edited by
    #3

    @SGaist Yes, I would run the executables from the command line. For example:

    $ ./HelloWorld -qws

    1 Reply Last reply
    0
    • S Offline
      S Offline
      SGaist
      Lifetime Qt Champion
      wrote on 1 Sept 2015, 19:58 last edited by
      #4

      And there's nothing showing up ? Or is the screen blacked ?

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

      J 1 Reply Last reply 1 Sept 2015, 19:59
      0
      • S SGaist
        1 Sept 2015, 19:58

        And there's nothing showing up ? Or is the screen blacked ?

        J Offline
        J Offline
        jkern
        wrote on 1 Sept 2015, 19:59 last edited by
        #5

        Right, there's no additional windows that pop up and the command line just moves on to the next prompt line.

        1 Reply Last reply
        0
        • S Offline
          S Offline
          SGaist
          Lifetime Qt Champion
          wrote on 1 Sept 2015, 20:12 last edited by
          #6

          That's strange, it should not do that.

          Are you sure app.exec() is called properly ?

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

          1 Reply Last reply
          0
          • J Offline
            J Offline
            jkern
            wrote on 1 Sept 2015, 20:15 last edited by jkern 9 Jan 2015, 20:15
            #7

            I literally haven't read anything about developing Qt programs yet. But as a trivial example, I created a Qt Widgets Application and just kept the default code. As a test, I compiled it with Qt 5.2.1 on my host machine, and it comes up with an empty window. So you would expect this same code is working on the target if cross-compiled correctly.

            1 Reply Last reply
            0
            • S Offline
              S Offline
              SGaist
              Lifetime Qt Champion
              wrote on 1 Sept 2015, 20:19 last edited by
              #8

              Good thinking, did you check that you have all the necessary rights to access the devices e.g. the frame buffer ?

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

              1 Reply Last reply
              0
              • J Offline
                J Offline
                jkern
                wrote on 1 Sept 2015, 20:20 last edited by
                #9

                No, how do you do that? (I'm new to Linux as well...)

                1 Reply Last reply
                0
                • S Offline
                  S Offline
                  SGaist
                  Lifetime Qt Champion
                  wrote on 1 Sept 2015, 20:22 last edited by
                  #10

                  groups to know the groups your user is a member of.
                  ls -la /dev/fb0 or ls -la /dev/fb/0 to see what permissions are set

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

                  1 Reply Last reply
                  0
                  • J Offline
                    J Offline
                    jkern
                    wrote on 1 Sept 2015, 20:25 last edited by
                    #11

                    groups shows:
                    analog adm dialout cdrom audio dip video plugdev admin

                    ls -la /dev/fb0 shows:
                    crw-rw---- 1 root video 29, 0 Jan 1 00:00 /dev/fb0

                    1 Reply Last reply
                    0
                    • S Offline
                      S Offline
                      SGaist
                      Lifetime Qt Champion
                      wrote on 1 Sept 2015, 20:28 last edited by
                      #12

                      Looks good.

                      Then, you should use gdb to debug your application

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

                      1 Reply Last reply
                      0

                      12/12

                      1 Sept 2015, 20:28

                      • Login

                      • Login or register to search.
                      12 out of 12
                      • First post
                        12/12
                        Last post
                      0
                      • Categories
                      • Recent
                      • Tags
                      • Popular
                      • Users
                      • Groups
                      • Search
                      • Get Qt Extensions
                      • Unsolved