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Inconsistent behavior of QSerialPort on Debian

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qtserialportlinuxescpos
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  • S Offline
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    SGaist
    Lifetime Qt Champion
    wrote on 30 Jan 2016, 20:15 last edited by
    #9

    No QSerialPort and QextSerialPort are two different things.

    My question wasn't about having two applications running at the same time. Just if you had the possibility to test the communication with your printer with another application to ensure that the port parameters are correct and the port is working correctly.

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    • H Offline
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      Hjunior
      wrote on 31 Jan 2016, 10:33 last edited by Hjunior
      #10

      Hmm, I see. Since it is a RS232 based printer i have no other program by this way. But it has linux driver to work with CUPS. I can test with it tomorrow and will post the results.

      Actually, i want to ask you about my design. I have a BaseSerialDevice class and QSerialPort is a private pointer stored in BaseSerialDevice.h and created in createPort@BaseSerialDevice.cpp.
      Then I have an EscPos class which extends BaseSerialDevice and calls createPort in constructor. I have 2 more classes extending the same BaseSerialDevice as same as EscPos. They working without any issue. At a time all of the 3 ports must be open and work. The other 2 has no problem. I checked the IRQs and tried several things but nothing changed. One more idea is they are all attached to MainWindow so they are in same thread. May this be the issue? Or is the setup issue? Or has QSerialPort a hidden bug?

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      • S Offline
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        SGaist
        Lifetime Qt Champion
        wrote on 31 Jan 2016, 20:40 last edited by
        #11

        From your description, are you opening the same port 3 times ?

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        • H Offline
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          Hjunior
          wrote on 1 Feb 2016, 07:48 last edited by Hjunior 2 Jan 2016, 10:17
          #12

          No friend they use base same class. The instances are set to use DIFFERENT PORTS as ttyS1,ttyS4,ttyS6

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          • S Offline
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            SGaist
            Lifetime Qt Champion
            wrote on 3 Feb 2016, 22:05 last edited by
            #13

            All of them physical ports of your computer or converter like usb to serial ?

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            H 1 Reply Last reply 4 Feb 2016, 12:50
            0
            • S SGaist
              3 Feb 2016, 22:05

              All of them physical ports of your computer or converter like usb to serial ?

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              Hjunior
              wrote on 4 Feb 2016, 12:50 last edited by
              #14

              @SGaist Yes all of them are phsical ports of my computer. NO usb to serial.

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              • S Offline
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                SGaist
                Lifetime Qt Champion
                wrote on 4 Feb 2016, 20:29 last edited by
                #15

                Does it also happen if you change devices e.g. exchange the devices from ttyS1 and ttyS6.

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                H 1 Reply Last reply 15 Feb 2016, 08:12
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                • S SGaist
                  4 Feb 2016, 20:29

                  Does it also happen if you change devices e.g. exchange the devices from ttyS1 and ttyS6.

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                  Hjunior
                  wrote on 15 Feb 2016, 08:12 last edited by
                  #16

                  @SGaist No difference.

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                  • S Offline
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                    SGaist
                    Lifetime Qt Champion
                    wrote on 15 Feb 2016, 21:50 last edited by
                    #17

                    Does the devies need the DTR to be set ?

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                    H 1 Reply Last reply 21 Feb 2016, 14:05
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                    • S SGaist
                      15 Feb 2016, 21:50

                      Does the devies need the DTR to be set ?

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                      Hjunior
                      wrote on 21 Feb 2016, 14:05 last edited by
                      #18

                      @SGaist Yes the device uses Hardware flow control and in the technical manual says it uses DTR/DSR.

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                      • S Offline
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                        SGaist
                        Lifetime Qt Champion
                        wrote on 21 Feb 2016, 20:37 last edited by
                        #19

                        Silly question but, did you set DTR in your application ?

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                        • H Offline
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                          Hjunior
                          wrote on 12 May 2016, 14:23 last edited by
                          #20

                          Hello again,

                          I finally figured out how this occurs.

                          BaseSerialDevice.cpp

                          class BaseSerialDevice : public QObject
                          {
                              Q_OBJECT
                          ....
                          protected:
                              QSerialPort *serial;
                          ....
                          

                          Problematic.cpp

                          class Problematic : public BaseSerialDevice
                          {
                              Q_OBJECT
                          ...
                          

                          MainWindow.h

                          ...
                          private:
                              Problematic worksLikeACharm;
                          

                          Everything works as expected if defined as a NON-POINTER but if;
                          MainWindow.h

                          ...
                          private:
                              Problematic* notWorksSo;
                          

                          then in MainWindow.cpp's constructor:

                          notWorksSo = new Problematic(parent()); 
                          or 
                          notWorksSo = new Problematic(NULL); 
                          or 
                          notWorksSo = new Problematic;
                          

                          the problem occurs as defined at the start of this topic. And same situation occurs if we use QSocket as same architecture.

                          I tested it from scratch at least 6 times. Im sure of that case.

                          And Cant believe and cant understand why?

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                          • S Offline
                            S Offline
                            SGaist
                            Lifetime Qt Champion
                            wrote on 12 May 2016, 20:04 last edited by
                            #21

                            And if you build it with Problematic(this) ?

                            When you don't pass it a parent, do you delete it in the destructor of your MainWindow ?

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                            H 1 Reply Last reply 13 May 2016, 06:34
                            0
                            • S SGaist
                              12 May 2016, 20:04

                              And if you build it with Problematic(this) ?

                              When you don't pass it a parent, do you delete it in the destructor of your MainWindow ?

                              H Offline
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                              Hjunior
                              wrote on 13 May 2016, 06:34 last edited by
                              #22

                              @SGaist Hi.

                              I am tried with Problematic(this) no change. In case of no parent arg i tried with delete, but nothing changed.

                              I tried making it static as
                              MainWindow.h

                              static Problematic* notWorksSo;
                              

                              MainWindow.cpp

                              Problematic* MainWindow::notWorksSo = 0;
                              

                              then in constructor

                              notWorksSo = new Problematic(this); 
                              

                              NOTHING CHANGED.

                              Any ideas?

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                              • S Offline
                                S Offline
                                SGaist
                                Lifetime Qt Champion
                                wrote on 13 May 2016, 20:04 last edited by
                                #23

                                Without seeing the implementation of these classes I can't tell.

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