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Multi serial port application

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  • mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by
    #15

    @veera said in multi serial port application:

    void Dialog :: open_serialport()
    {
    QSerialPort serial; <<<< WRONG ! its local variable

    make it a class member of Dialog

    1 Reply Last reply
    3
    • V Offline
      V Offline
      veera
      wrote on last edited by
      #16

      @mrjj ,
      just now declared a QSerialPort as data members of the dialog class in dialog.h still also i am getting same error...

      here is the declaration of the QSerialPort

      #ifndef DIALOG_H
      #define DIALOG_H

      #include <QDialog>
      #include <stdio.h>
      #include <QtSerialPort/QSerialPort>
      
      
      namespace Ui {
      class Dialog;
      }
      
      class Dialog : public QDialog
      {
          Q_OBJECT
      
      public:
          QSerialPort serial;
      
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      0
      • mrjjM Offline
        mrjjM Offline
        mrjj
        Lifetime Qt Champion
        wrote on last edited by
        #17

        Super
        but what error ?

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        0
        • V Offline
          V Offline
          veera
          wrote on last edited by
          #18

          can not able to open the serial port..what was the type its receiving whether its ttyS4 or /dev/ttyS4?

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          0
          • V Offline
            V Offline
            veera
            wrote on last edited by
            #19

            @mrjj ,
            I am directly assigning the portname from gui qcombox is it correct way for accessing the port name ?

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            • mrjjM Offline
              mrjjM Offline
              mrjj
              Lifetime Qt Champion
              wrote on last edited by
              #20

              Hi
              normally its ttyS4
              for
              serial->setPortName(p.name);

              Did you see the sample
              http://doc.qt.io/qt-5/qtserialport-terminal-example.html

              Its available directly in Creator and you can use to test.

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              0
              • V Offline
                V Offline
                veera
                wrote on last edited by
                #21

                yes i have refer that example only.....

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                • V Offline
                  V Offline
                  veera
                  wrote on last edited by
                  #22

                  i have tried both the things not able to open the port .....

                  mrjjM 1 Reply Last reply
                  0
                  • V veera

                    i have tried both the things not able to open the port .....

                    mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by mrjj
                    #23

                    @veera

                    so are you sure PC has that port ?

                    if using a serial usb adapter, it has other name.

                    If you cannot open port using the Terminal sample then
                    something is wrong outside Qt.

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                    0
                    • V Offline
                      V Offline
                      veera
                      wrote on last edited by
                      #24

                      yes having two ports only ttyS4 and ttyS5 i am not using any usb to serial converter i am directly connecting with serial port only .....i have tried terminal example its giving the permission error means sudo permission .....

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                      • V Offline
                        V Offline
                        veera
                        wrote on last edited by
                        #25

                        permission is denied error while opening the port in Terminal Sample...

                        jsulmJ 1 Reply Last reply
                        0
                        • V veera

                          permission is denied error while opening the port in Terminal Sample...

                          jsulmJ Offline
                          jsulmJ Offline
                          jsulm
                          Lifetime Qt Champion
                          wrote on last edited by
                          #26

                          @veera What does

                          ls -lh /dev/ttyS4
                          

                          say?

                          https://forum.qt.io/topic/113070/qt-code-of-conduct

                          1 Reply Last reply
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                          • mrdebugM Offline
                            mrdebugM Offline
                            mrdebug
                            wrote on last edited by
                            #27

                            Are you in dialout group?

                            Need programmers to hire?
                            www.labcsp.com
                            www.denisgottardello.it
                            GMT+1
                            Skype: mrdebug

                            1 Reply Last reply
                            1
                            • V Offline
                              V Offline
                              veera
                              wrote on last edited by
                              #28

                              i tried using this command on the qt project path also not able to open the serial ports.....

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                              0
                              • V Offline
                                V Offline
                                veera
                                wrote on last edited by
                                #29

                                yes i am in dialout group....

                                1 Reply Last reply
                                0
                                • V Offline
                                  V Offline
                                  veera
                                  wrote on last edited by
                                  #30

                                  crw-rw---- 1 root dialout 4, 68 Dec 11 13:22 /dev/ttyS4

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                                  0
                                  • V Offline
                                    V Offline
                                    veera
                                    wrote on last edited by
                                    #31

                                    @jsulm said in multi serial port application:

                                    ls -lh /dev/ttyS4

                                    crw-rw---- 1 root dialout 4, 68 Dec 11 13:22 /dev/ttyS4

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                                    0
                                    • mrdebugM Offline
                                      mrdebugM Offline
                                      mrdebug
                                      wrote on last edited by
                                      #32

                                      Are you sure you really have 4 serial ports? Which kind of machine have you got?
                                      In some case, with a beaglebone board for example, you have to enable the third and fourth serial port with a special kernel parameter.

                                      Need programmers to hire?
                                      www.labcsp.com
                                      www.denisgottardello.it
                                      GMT+1
                                      Skype: mrdebug

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                                      1
                                      • mrjjM Offline
                                        mrjjM Offline
                                        mrjj
                                        Lifetime Qt Champion
                                        wrote on last edited by
                                        #33

                                        Hi
                                        Often you have to add your user to the dialout group to be allowed to use it

                                        usermod -a -G dialout MY_USER_NAME

                                        as @mrdebug asks/says

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                                        0
                                        • V Offline
                                          V Offline
                                          veera
                                          wrote on last edited by
                                          #34

                                          @mrdebug
                                          I have only two serial ports i am connecting slot machine to my desktop computer.....need to connect from desktop to slot machine i am struggling to open the serial port please help me i have added like this

                                          1 Reply Last reply
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