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Read data RS232 without pooling

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  • M Offline
    M Offline
    mehdi.nine
    wrote on last edited by
    #1

    i read data from RS232 in a for loop.this has no good performance.i want don't have a for loop instead of that there was a thing like event that when data is receiving it fire. is this possible? for example when data is receiving from COM16 event firing.

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    • M Offline
      M Offline
      MuldeR
      wrote on last edited by
      #2

      You give absolutely no info what API you are currently using to read from COM port.

      Anyway, if that API has a blocking call, that will not return before new data is available, you can simply use that one, in a loop, and put that loop into a background thread. Then send a signal as soon as new data is available.

      Like:
      @MyThread::run()
      {
      forever
      {
      readDataFromComPort_blocking();
      emit newDataAvailable();
      }
      }@

      My OpenSource software at: http://muldersoft.com/

      Qt v4.8.6 MSVC 2013, static/shared: http://goo.gl/BXqhrS

      Go visit the coop: http://youtu.be/Jay...

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      • M Offline
        M Offline
        mehdi.nine
        wrote on last edited by
        #3

        thanks for your reply. how can i have blocking call for that? i can't implement
        @
        readDataFromComPort_blocking();
        @
        function.

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        • M Offline
          M Offline
          MuldeR
          wrote on last edited by
          #4

          Tell us what API you are using to read from the COM port, if you expect an answer on this ;-)

          My OpenSource software at: http://muldersoft.com/

          Qt v4.8.6 MSVC 2013, static/shared: http://goo.gl/BXqhrS

          Go visit the coop: http://youtu.be/Jay...

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          • D Offline
            D Offline
            DerManu
            wrote on last edited by
            #5

            I'm using QExtSerialPort very successfully in an application that doesn't poll, either.
            http://code.google.com/p/qextserialport/

            It makes this possible by emitting a readyRead signal, as soon as data is available.

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            • K Offline
              K Offline
              kuzulis
              Qt Champions 2020
              wrote on last edited by
              #6

              You can also use official "QtSerialPort":http://qt-project.org/wiki/QtSerialPort addon.

              See documentation about API and examples "here":http://doc-snapshot.qt-project.org/qt5-stable/qtserialport/qtserialport-index.html.

              Therefore there is no need of use of your custom code.

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