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How to append the serial read data on to the QPlaintext on qt gui window

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  • aha_1980A Offline
    aha_1980A Offline
    aha_1980
    Lifetime Qt Champion
    wrote on last edited by
    #5

    @veera said in How to append the serial read data on to the QPlaintext on qt gui window:

    if(serial.waitForReadyRead(20000)){

    That may be the cause of your problem.

    You will most likely use the readyRead signal and connect it to your slot where you read all the data.

    I have given you already the link to the terminal example in you other thread, please take that as reference.

    Qt has to stay free or it will die.

    1 Reply Last reply
    0
    • V veera

      I am reading a data as serial.readall()

       if(serial.waitForReadyRead(20000)){
                              //Data was returned
                             // QString ser_Buffer = serial.readAll();
                              qDebug()<<"Response: "<<serial.readAll();
                             //ui->ResWindow_plainTextEdit->appendPlainText(serial.readAll());
      
                              //QTextCursor cursor(plainTextEdit->document());
                              QTextCursor cursor(ui->ResWindow_plainTextEdit->document());
                              cursor.movePosition(QTextCursor::End);
                              //cursor.insertText(QString::fromUtf8(serialData));
                              cursor.insertText(QString::fromUtf8(serial.readAll()));
      
      
                             // ui->ResWindow_plainTextEdit->appendPlainText(serial.readAll());
                              usleep(200000);
                          }else{
                              //No data
                              qDebug()<<"Time out";
                          }
      
                          //I have finish alla operation
                          serial.close();
                      }else{
                          qDebug()<<"Serial ttyS4 not opened. Error: "<<serial.errorString();
                      }
      

      still not able to display on the QPlainText...

      VRoninV Offline
      VRoninV Offline
      VRonin
      wrote on last edited by VRonin
      #6

      after qDebug()<<"Response: "<<serial.readAll();, serial will empty its buffer so cursor.insertText(QString::fromUtf8(serial.readAll())); appends nothing.

      const auto serialData = serial.readAll();
      qDebug()<<"Response: "<<serialData;
      QTextCursor cursor(ui->ResWindow_plainTextEdit->document());
      cursor.movePosition(QTextCursor::End);
      cursor.insertText(QString::fromUtf8(serialData));
      

      "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
      ~Napoleon Bonaparte

      On a crusade to banish setIndexWidget() from the holy land of Qt

      1 Reply Last reply
      4
      • V Offline
        V Offline
        veera
        wrote on last edited by
        #7

        @VRonin

        i got this
        E�
        E�
        E�
        E�
        �
        E�
        E�
        E�
        E�
        �

        VRoninV 1 Reply Last reply
        0
        • V veera

          @VRonin

          i got this
          E�
          E�
          E�
          E�
          �
          E�
          E�
          E�
          E�
          �

          VRoninV Offline
          VRoninV Offline
          VRonin
          wrote on last edited by
          #8

          What does qDebug()<<"Response: "<<serialData; print?

          "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
          ~Napoleon Bonaparte

          On a crusade to banish setIndexWidget() from the holy land of Qt

          1 Reply Last reply
          1
          • V Offline
            V Offline
            veera
            wrote on last edited by
            #9

            yes its writing on plaintext window.......

            qDebug()<<"Response: "<<serialData; print?

            Response: "\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01"
            The portName is "ttyS4"
            currentPortName "ttyS4"
            Response: "\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01"

            VRoninV 1 Reply Last reply
            0
            • V Offline
              V Offline
              veera
              wrote on last edited by
              #10

              @VRonin
              I am getting the response as a hex bytes only so how to display onto the QPlainText ..

              aha_1980A 1 Reply Last reply
              0
              • T Offline
                T Offline
                Tirupathi Korla
                wrote on last edited by Tirupathi Korla
                #11

                @veera
                Hi,
                Serial.readall() returns QByteArray. Have you tried this?

                QString res(serialData);
                ui->ResWindow_plainTextEdit->appendPlainText(res);
                

                And one more question. Is that if(serial.waitForReadyRead(20000)) condition running inside any loop?

                -Tirupathi

                1 Reply Last reply
                0
                • V veera

                  @VRonin
                  I am getting the response as a hex bytes only so how to display onto the QPlainText ..

                  aha_1980A Offline
                  aha_1980A Offline
                  aha_1980
                  Lifetime Qt Champion
                  wrote on last edited by
                  #12

                  @veera said in How to append the serial read data on to the QPlaintext on qt gui window:

                  @VRonin
                  I am getting the response as a hex bytes only so how to display onto the QPlainText ..

                  If you want to show the hex bytes in the text edit, you can use (modified @VRonin's example (the change is the toHex() in the first line):

                  const auto serialData = serial.readAll().toHex();
                  qDebug()<<"Response: "<<serialData;
                  QTextCursor cursor(ui->ResWindow_plainTextEdit->document());
                  cursor.movePosition(QTextCursor::End);
                  cursor.insertText(QString::fromUtf8(serialData));
                  

                  Note that you could replace QString::fromUtf8() with QString::fromLatin1() in that case.

                  Qt has to stay free or it will die.

                  1 Reply Last reply
                  0
                  • V veera

                    yes its writing on plaintext window.......

                    qDebug()<<"Response: "<<serialData; print?

                    Response: "\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01"
                    The portName is "ttyS4"
                    currentPortName "ttyS4"
                    Response: "\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01"

                    VRoninV Offline
                    VRoninV Offline
                    VRonin
                    wrote on last edited by
                    #13

                    @veera said in How to append the serial read data on to the QPlaintext on qt gui window:

                    Response: "\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01"

                    \x01 is not printable. What did you expect to see?

                    "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
                    ~Napoleon Bonaparte

                    On a crusade to banish setIndexWidget() from the holy land of Qt

                    1 Reply Last reply
                    0
                    • V Offline
                      V Offline
                      veera
                      wrote on last edited by
                      #14

                      okay fine ...but response is coming what i am expecting i am writing some data for serial port like
                      unsigned char rteenab[] = {0X01,0X0E,0X01,0X45,0XD1}; i am trying to print input and output onto the QPlaintext ......

                      J.HilkJ 1 Reply Last reply
                      0
                      • V veera

                        okay fine ...but response is coming what i am expecting i am writing some data for serial port like
                        unsigned char rteenab[] = {0X01,0X0E,0X01,0X45,0XD1}; i am trying to print input and output onto the QPlaintext ......

                        J.HilkJ Offline
                        J.HilkJ Offline
                        J.Hilk
                        Moderators
                        wrote on last edited by
                        #15

                        @veera
                        You'll have to create a formated QString out of your Qbytearray for that. @VRonin and @aha_1980 showed you how to do it, heres a 3rd Way(I prefere a seperation and a more readable String):

                        const auto serialData = serial.readAll()
                        qDebug()<<"Response: "<<serialData;
                        
                        QString formatedText;
                        for(int i(0); i<serialData .size(); i++)
                            formatedText.append(QString::number((serialData.at(i),16).toUpper().rightJustified(2,'0')+ QChar(0x20));
                        
                        QTextCursor cursor(ui->ResWindow_plainTextEdit->document());
                        cursor.movePosition(QTextCursor::End);
                        cursor.insertText(formatedText);
                        

                        Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                        Q: What's that?
                        A: It's blue light.
                        Q: What does it do?
                        A: It turns blue.

                        aha_1980A 1 Reply Last reply
                        1
                        • J.HilkJ J.Hilk

                          @veera
                          You'll have to create a formated QString out of your Qbytearray for that. @VRonin and @aha_1980 showed you how to do it, heres a 3rd Way(I prefere a seperation and a more readable String):

                          const auto serialData = serial.readAll()
                          qDebug()<<"Response: "<<serialData;
                          
                          QString formatedText;
                          for(int i(0); i<serialData .size(); i++)
                              formatedText.append(QString::number((serialData.at(i),16).toUpper().rightJustified(2,'0')+ QChar(0x20));
                          
                          QTextCursor cursor(ui->ResWindow_plainTextEdit->document());
                          cursor.movePosition(QTextCursor::End);
                          cursor.insertText(formatedText);
                          
                          aha_1980A Offline
                          aha_1980A Offline
                          aha_1980
                          Lifetime Qt Champion
                          wrote on last edited by
                          #16

                          @J.Hilk: Note that for Qt 5.9 I added an overload of QByteArray::toHex(char separator) [1] where you can do something like

                          QByteArray hexData = data.toHex(' '); directly :)

                          [1] http://doc.qt.io/qt-5/qbytearray.html#toHex-1

                          Qt has to stay free or it will die.

                          J.HilkJ 1 Reply Last reply
                          4
                          • aha_1980A aha_1980

                            @J.Hilk: Note that for Qt 5.9 I added an overload of QByteArray::toHex(char separator) [1] where you can do something like

                            QByteArray hexData = data.toHex(' '); directly :)

                            [1] http://doc.qt.io/qt-5/qbytearray.html#toHex-1

                            J.HilkJ Offline
                            J.HilkJ Offline
                            J.Hilk
                            Moderators
                            wrote on last edited by J.Hilk
                            #17

                            @aha_1980 oO, I should read the change logs more thoroughly! Makes my life easier ;-) thanks!


                            Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                            Q: What's that?
                            A: It's blue light.
                            Q: What does it do?
                            A: It turns blue.

                            1 Reply Last reply
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