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Cannot output a value using QSerialPort

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  • Christian EhrlicherC Christian Ehrlicher

    @mrjj said in Cannot output a value using QSerialPort:

    You call setBaudRate, setDataBits etc AFTER you open port. that is wrong.

    I already said this some days ago: https://forum.qt.io/topic/112346/cannot-output-a-value-using-qserialport/23 but it is simply ignored...

    mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by
    #46

    @Christian-Ehrlicher
    Indeed and also @jsulm also noted to check open which seems to be forgotten also.

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    • K Offline
      K Offline
      kuzulis
      Qt Champions 2020
      wrote on last edited by
      #47

      @mrjj said in Cannot output a value using QSerialPort:

      You call setBaudRate, setDataBits etc AFTER you open port. that is wrong.
      must be before open!

      This is not true. You can configure QSP in any time.

      mrjjM Pablo J. RoginaP 2 Replies Last reply
      1
      • K kuzulis

        @mrjj said in Cannot output a value using QSerialPort:

        You call setBaudRate, setDataBits etc AFTER you open port. that is wrong.
        must be before open!

        This is not true. You can configure QSP in any time.

        mrjjM Offline
        mrjjM Offline
        mrjj
        Lifetime Qt Champion
        wrote on last edited by
        #48

        @kuzulis
        Ok
        thank you for clarifying that.
        Over the years I have not had huge success with that without close and reopen the port but its
        good to know QSerialPort does support it :)

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        0
        • K kuzulis

          @mrjj said in Cannot output a value using QSerialPort:

          You call setBaudRate, setDataBits etc AFTER you open port. that is wrong.
          must be before open!

          This is not true. You can configure QSP in any time.

          Pablo J. RoginaP Offline
          Pablo J. RoginaP Offline
          Pablo J. Rogina
          wrote on last edited by
          #49

          @kuzulis said in Cannot output a value using QSerialPort:

          This is not true. You can configure QSP in any time.

          Are you saying that you can change the settings once a connection has been established?

          Upvote the answer(s) that helped you solve the issue
          Use "Topic Tools" button to mark your post as Solved
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          Don't ask support requests via chat/PM. Please use the forum so others can benefit from the solution in the future

          mrjjM 1 Reply Last reply
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          • Pablo J. RoginaP Pablo J. Rogina

            @kuzulis said in Cannot output a value using QSerialPort:

            This is not true. You can configure QSP in any time.

            Are you saying that you can change the settings once a connection has been established?

            mrjjM Offline
            mrjjM Offline
            mrjj
            Lifetime Qt Champion
            wrote on last edited by
            #50

            @Pablo-J-Rogina

            Yes seems so and he should know as he wrote it :)

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            • K Offline
              K Offline
              kuzulis
              Qt Champions 2020
              wrote on last edited by
              #51

              @Pablo-J-Rogina said in Cannot output a value using QSerialPort:

              Are you saying that you can change the settings once a connection has been established?

              Of course, after open() you can do what you need.

              Pablo J. RoginaP 1 Reply Last reply
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              • K kuzulis

                @Pablo-J-Rogina said in Cannot output a value using QSerialPort:

                Are you saying that you can change the settings once a connection has been established?

                Of course, after open() you can do what you need.

                Pablo J. RoginaP Offline
                Pablo J. RoginaP Offline
                Pablo J. Rogina
                wrote on last edited by
                #52

                @kuzulis but changing the settings once you open the port, does impact on the ongoing connection?
                I mean, does the other side need to update the settings as well? And if so, won't the connection be interrupted?

                Upvote the answer(s) that helped you solve the issue
                Use "Topic Tools" button to mark your post as Solved
                Add screenshots via postimage.org
                Don't ask support requests via chat/PM. Please use the forum so others can benefit from the solution in the future

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                • K Offline
                  K Offline
                  kuzulis
                  Qt Champions 2020
                  wrote on last edited by kuzulis
                  #53

                  @Pablo-J-Rogina said in Cannot output a value using QSerialPort:

                  @kuzulis but changing the settings once you open the port, does impact on the ongoing connection?
                  I mean, does the other side need to update the settings as well? And if so, won't the connection be interrupted?

                  The serial communication has no "connection" things. About what "connection" do you speak?

                  PS: In reality (on a low level), any device configurations always changes after a device has been opened! This belongs to any device.

                  Pablo J. RoginaP 1 Reply Last reply
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                  • K kuzulis

                    @Pablo-J-Rogina said in Cannot output a value using QSerialPort:

                    @kuzulis but changing the settings once you open the port, does impact on the ongoing connection?
                    I mean, does the other side need to update the settings as well? And if so, won't the connection be interrupted?

                    The serial communication has no "connection" things. About what "connection" do you speak?

                    PS: In reality (on a low level), any device configurations always changes after a device has been opened! This belongs to any device.

                    Pablo J. RoginaP Offline
                    Pablo J. RoginaP Offline
                    Pablo J. Rogina
                    wrote on last edited by
                    #54

                    @kuzulis said in Cannot output a value using QSerialPort:

                    About what "connection" do you speak?

                    An ongoing transmission

                    Upvote the answer(s) that helped you solve the issue
                    Use "Topic Tools" button to mark your post as Solved
                    Add screenshots via postimage.org
                    Don't ask support requests via chat/PM. Please use the forum so others can benefit from the solution in the future

                    1 Reply Last reply
                    1
                    • K Offline
                      K Offline
                      kuzulis
                      Qt Champions 2020
                      wrote on last edited by kuzulis
                      #55

                      @Pablo-J-Rogina said in Cannot output a value using QSerialPort:

                      An ongoing transmission

                      In this case an ongoing data stream just will be transferred with a new parameters (speed, parity ant etc).

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