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Multi serial port application

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  • 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

    1 Reply Last reply
    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

      1 Reply Last reply
      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
        0
        • V Offline
          V Offline
          veera
          wrote on last edited by
          #35

          sudo usermod -a -G dialout veera

          1 Reply Last reply
          0
          • V Offline
            V Offline
            veera
            wrote on last edited by
            #36

            in my desktop using two serial ports using right now may be in built its four i guess.....

            jsulmJ 1 Reply Last reply
            0
            • V veera

              in my desktop using two serial ports using right now may be in built its four i guess.....

              jsulmJ Offline
              jsulmJ Offline
              jsulm
              Lifetime Qt Champion
              wrote on last edited by
              #37

              @veera Make sure your user is member of dialout group

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

              1 Reply Last reply
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              • mrjjM Offline
                mrjjM Offline
                mrjj
                Lifetime Qt Champion
                wrote on last edited by
                #38

                Also if you are having ONLY 2 serial ports why are you then
                trying the /dev/ttyS4 port ???
                i would giess on
                /dev/ttyS0
                or
                /dev/ttyS1

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                • V Offline
                  V Offline
                  veera
                  wrote on last edited by
                  #39

                  i have verified with minicom slot machine cable is connected with ttyS4 so i am trying with this port

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                  • V Offline
                    V Offline
                    veera
                    wrote on last edited by
                    #40

                    i have tried ttyS0 and ttyS1 also it is not able to open the serial port....

                    mrjjM 1 Reply Last reply
                    0
                    • V veera

                      i have tried ttyS0 and ttyS1 also it is not able to open the serial port....

                      mrjjM Offline
                      mrjjM Offline
                      mrjj
                      Lifetime Qt Champion
                      wrote on last edited by mrjj
                      #41

                      @veera

                      ok. not sure what could be wrong with your linux if you have added
                      yourself (your username) to dial out group and you are sure that the port exists.

                      What linux are you using ?

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                      • V Offline
                        V Offline
                        veera
                        wrote on last edited by
                        #42

                        ubuntu 16.04 LTS ,i opened serial port now if i choose the run in terminal its opening please help how to set sudo password in qt instead of choosing run in terminal directly need to open

                        aha_1980A 1 Reply Last reply
                        0
                        • V veera

                          ubuntu 16.04 LTS ,i opened serial port now if i choose the run in terminal its opening please help how to set sudo password in qt instead of choosing run in terminal directly need to open

                          aha_1980A Offline
                          aha_1980A Offline
                          aha_1980
                          Lifetime Qt Champion
                          wrote on last edited by
                          #43

                          @veera said in multi serial port application:

                          ubuntu 16.04 LTS ,i opened serial port now if i choose the run in terminal its opening please help how to set sudo password in qt instead of choosing run in terminal directly need to open

                          If you need the sudo password than setting yourself into dialout group did not work!

                          Have your rebooted your PC after you put yourself into dialout?

                          Hint: call error() when opening the serial port fails to get more information about the error.

                          Qt has to stay free or it will die.

                          jsulmJ 1 Reply Last reply
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                          • aha_1980A aha_1980

                            @veera said in multi serial port application:

                            ubuntu 16.04 LTS ,i opened serial port now if i choose the run in terminal its opening please help how to set sudo password in qt instead of choosing run in terminal directly need to open

                            If you need the sudo password than setting yourself into dialout group did not work!

                            Have your rebooted your PC after you put yourself into dialout?

                            Hint: call error() when opening the serial port fails to get more information about the error.

                            jsulmJ Offline
                            jsulmJ Offline
                            jsulm
                            Lifetime Qt Champion
                            wrote on last edited by
                            #44

                            @aha_1980 @veera Reboot is not needed: just log off and on again after adding yourself to the group.

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

                            aha_1980A 1 Reply Last reply
                            1
                            • V Offline
                              V Offline
                              veera
                              wrote on last edited by
                              #45

                              yes i have rebooted system now opened successfully ......Thank you so much

                              1 Reply Last reply
                              0
                              • V Offline
                                V Offline
                                veera
                                wrote on last edited by
                                #46

                                how to write and read the hexbytes such as unsigned char ch1[] = {0X01,0X04,0X0F} etc from serial port......

                                mrjjM 1 Reply Last reply
                                0
                                • V veera

                                  how to write and read the hexbytes such as unsigned char ch1[] = {0X01,0X04,0X0F} etc from serial port......

                                  mrjjM Offline
                                  mrjjM Offline
                                  mrjj
                                  Lifetime Qt Champion
                                  wrote on last edited by
                                  #47

                                  @veera
                                  Hi
                                  Hex is a notation and not a format.
                                  The bytes are still just bytes.
                                  QByteArray has
                                  QByteArray::fromHex
                                  http://doc.qt.io/qt-5/qbytearray.html#fromHex
                                  and
                                  http://doc.qt.io/qt-5/qbytearray.html#toHex

                                  1 Reply Last reply
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                                  • jsulmJ jsulm

                                    @aha_1980 @veera Reboot is not needed: just log off and on again after adding yourself to the group.

                                    aha_1980A Offline
                                    aha_1980A Offline
                                    aha_1980
                                    Lifetime Qt Champion
                                    wrote on last edited by
                                    #48

                                    @jsulm I know :) But it does not hurt either and before explaining what logging out an in again means...

                                    Qt has to stay free or it will die.

                                    1 Reply Last reply
                                    2
                                    • V Offline
                                      V Offline
                                      veera
                                      wrote on last edited by
                                      #49

                                      @mrjj ,
                                      Okay thanks i will try it now....

                                      1 Reply Last reply
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