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

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  • 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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