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QSerialPort

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  • SGaistS SGaist

    Hi,

    Is it expected that you read only one line ?
    You should rather get everything from the serial port, accumulate in a buffer and then process the data once you have a full frame (or more).

    T Offline
    T Offline
    Tomaz
    wrote on last edited by
    #4

    @SGaist Hi SGaist. Everytime is good to read your replies. Yes. I control what is being red and it is one line from arduino loop (simple sensor data). Thomas

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    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #5

      Can you share also the thread related code ?

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      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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      • Pl45m4P Pl45m4

        @Tomaz

        What do you expect from emitting a signal in a while(1) loop?!
        It will never get processed

        Edit:
        Ah havent seen your comment. You only emit once when the loop has ended.

        Have a look at the synchronous and asynchronous QSerialPort examples here:

        • https://doc.qt.io/qt-6/qtserialport-blockingreceiver-example.html
        • https://doc.qt.io/qt-6/qtserialport-terminal-example.html
        T Offline
        T Offline
        Tomaz
        wrote on last edited by Tomaz
        #6

        @Pl45m4 Hi.
        I am sorry but the code is correct on syntax, semantic and semiotic/pragmatic level. The creation of and object has to happen inside the working loop I concluded; (in run loop). I think it has to do with usb port access on low level (QSerialPort c/c++ Qt code). I think. The error is gone now.

        I got it from one of SGaist comments/replies.

        Perhaps SGaist could give us more enlightenment why it has to be inside run loop (or custom loop like I have)? Perhaps because it is made on heap?

        regards, Thomas

        T 1 Reply Last reply
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        • T Tomaz

          @Pl45m4 Hi.
          I am sorry but the code is correct on syntax, semantic and semiotic/pragmatic level. The creation of and object has to happen inside the working loop I concluded; (in run loop). I think it has to do with usb port access on low level (QSerialPort c/c++ Qt code). I think. The error is gone now.

          I got it from one of SGaist comments/replies.

          Perhaps SGaist could give us more enlightenment why it has to be inside run loop (or custom loop like I have)? Perhaps because it is made on heap?

          regards, Thomas

          T Offline
          T Offline
          Tomaz
          wrote on last edited by
          #7

          @Tomaz No it is not the heap problem. Perhaps of the scope object is living in?

          K 1 Reply Last reply
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          • T Tomaz

            @Tomaz No it is not the heap problem. Perhaps of the scope object is living in?

            K Offline
            K Offline
            kuzulis
            Qt Champions 2020
            wrote on last edited by
            #8

            @Tomaz

            Right now everything is wrong in your code.

            Christian EhrlicherC 1 Reply Last reply
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            • K kuzulis

              @Tomaz

              Right now everything is wrong in your code.

              Christian EhrlicherC Offline
              Christian EhrlicherC Offline
              Christian Ehrlicher
              Lifetime Qt Champion
              wrote on last edited by
              #9

              Where is readttyUSB0 instantiated / is it moved to a thread somewhere? If yes then you forgot to move sPort (btw: very strange name for a member var) as it has no parent.

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              • Christian EhrlicherC Christian Ehrlicher

                Where is readttyUSB0 instantiated / is it moved to a thread somewhere? If yes then you forgot to move sPort (btw: very strange name for a member var) as it has no parent.

                T Offline
                T Offline
                Tomaz
                wrote on last edited by Tomaz
                #10

                @Christian-Ehrlicher Hi. Sorry for my late reply. Well it is in mainwindow constructor. This is in constructor.

                rttyUSB0->moveToThread(threadttyUSB0);
                connect(threadttyUSB0,SIGNAL(started()),rttyUSB0,SLOT(doWork()));
                connect(rttyUSB0,SIGNAL(usb0Data(QString)),this,SLOT(readSerialCom(QString)));
                threadttyUSB0->start();```
                

                Declared in .h file in private part.

                What I do in readSerialCom(QString) is not important.

                I let this loop to run for a week with no problem. No compile error. Should be ok.

                Thomas

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                • SGaistS SGaist

                  Can you share also the thread related code ?

                  T Offline
                  T Offline
                  Tomaz
                  wrote on last edited by
                  #11

                  @SGaist Hi. SGaist. One question. What is the best way (board?) to boot Linux into Qt graphic App (I need access to /dev- USB) in max 2 to 3 seconds? But to be on open source non commercial side. I tried raspberry Pi and eglfs but it needs 10 seconds. regards Thomas

                  Ronel_qtmasterR SGaistS 2 Replies Last reply
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                  • T Tomaz

                    @SGaist Hi. SGaist. One question. What is the best way (board?) to boot Linux into Qt graphic App (I need access to /dev- USB) in max 2 to 3 seconds? But to be on open source non commercial side. I tried raspberry Pi and eglfs but it needs 10 seconds. regards Thomas

                    Ronel_qtmasterR Offline
                    Ronel_qtmasterR Offline
                    Ronel_qtmaster
                    wrote on last edited by
                    #12

                    @Tomaz if you are using yocto, you can disable certain services at start or change the boot order by prioritising your app

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                    • T Tomaz

                      @SGaist Hi. SGaist. One question. What is the best way (board?) to boot Linux into Qt graphic App (I need access to /dev- USB) in max 2 to 3 seconds? But to be on open source non commercial side. I tried raspberry Pi and eglfs but it needs 10 seconds. regards Thomas

                      SGaistS Offline
                      SGaistS Offline
                      SGaist
                      Lifetime Qt Champion
                      wrote on last edited by
                      #13

                      @Tomaz hi,

                      It depends on what your device has to do, which services are required, etc.

                      Based on that you can optimize some things to reduce boot time.

                      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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