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opening of serial port

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  • jsulmJ jsulm

    @Nimika "it is opening but whenver I am writing or reading in that port its showing device not open" - are you sure you opened the port? Did you check it like this:

    qDebug() << serial.open(QIODevice::ReadWrite);
    
    N Offline
    N Offline
    Nimika
    wrote on last edited by VRonin
    #3

    @jsulm
    i just checked it and it is showing false.
    I wrote this program.

    #include <QCoreApplication>
    #include <QSerialPort>
    #include <QDebug>
    
    QSerialPort serial;
    int main(int argc, char *argv[])
    {
        QCoreApplication a(argc, argv);
        serial.setPortName("ttyM");
        serial.setBaudRate(QSerialPort::Baud115200);
        serial.setDataBits(QSerialPort::Data8);
        serial.setStopBits(QSerialPort::OneStop);
        serial.setParity(QSerialPort::NoParity);
        serial.setFlowControl(QSerialPort::NoFlowControl);
       serial.open(QIODevice::ReadWrite);
       qDebug() << "port connected";
       qDebug() << serial.open(QIODevice::ReadWrite);
       serial.write("hello");
    QByteArray bb = serial.readAll();
    qDebug() << bb ;
       serial.close();
        return a.exec();
    }
    
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    • N Offline
      N Offline
      Nimika
      wrote on last edited by
      #4

      @jsulm
      where am I lacking I don't understand.
      Or maybe this is the problem in MOXA port.

      jsulmJ 2 Replies Last reply
      0
      • N Nimika

        @jsulm
        where am I lacking I don't understand.
        Or maybe this is the problem in MOXA port.

        jsulmJ Offline
        jsulmJ Offline
        jsulm
        Lifetime Qt Champion
        wrote on last edited by
        #5

        @Nimika
        That's wrong:

        serial.open(QIODevice::ReadWrite);
        qDebug() << "port connected";
        qDebug() << serial.open(QIODevice::ReadWrite);
        

        do it like this (do not call open twice!):

        qDebug() << "port connected";
        qDebug() << serial.open(QIODevice::ReadWrite);
        

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

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        • N Nimika

          @jsulm
          where am I lacking I don't understand.
          Or maybe this is the problem in MOXA port.

          jsulmJ Offline
          jsulmJ Offline
          jsulm
          Lifetime Qt Champion
          wrote on last edited by
          #6

          @Nimika If it still not able to open the connection then check all the connection parameters you're specifying.

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

          N 1 Reply Last reply
          0
          • N Offline
            N Offline
            Nimika
            wrote on last edited by
            #7

            Ok but still it is not working when I am using the single open function.

            mrjjM 1 Reply Last reply
            0
            • N Nimika

              Ok but still it is not working when I am using the single open function.

              mrjjM Offline
              mrjjM Offline
              mrjj
              Lifetime Qt Champion
              wrote on last edited by
              #8

              @Nimika
              Hi are you 100% sure about portname ?
              serial.setPortName("ttyM");
              I would expect a number ttyM0

              N 1 Reply Last reply
              0
              • mrjjM mrjj

                @Nimika
                Hi are you 100% sure about portname ?
                serial.setPortName("ttyM");
                I would expect a number ttyM0

                N Offline
                N Offline
                Nimika
                wrote on last edited by
                #9

                @mrjj
                Oh sorry by mistake I have written that but I am using ttyM0 only.

                mrjjM 1 Reply Last reply
                1
                • N Nimika

                  @mrjj
                  Oh sorry by mistake I have written that but I am using ttyM0 only.

                  mrjjM Offline
                  mrjjM Offline
                  mrjj
                  Lifetime Qt Champion
                  wrote on last edited by
                  #10

                  @Nimika
                  Ok. Just checking.

                  Did you try with minicom or any other serial programs if it will open it ?

                  N 1 Reply Last reply
                  0
                  • mrjjM mrjj

                    @Nimika
                    Ok. Just checking.

                    Did you try with minicom or any other serial programs if it will open it ?

                    N Offline
                    N Offline
                    Nimika
                    wrote on last edited by
                    #11

                    @mrjj
                    Its not working with any case.

                    mrjjM 1 Reply Last reply
                    0
                    • N Nimika

                      @mrjj
                      Its not working with any case.

                      mrjjM Offline
                      mrjjM Offline
                      mrjj
                      Lifetime Qt Champion
                      wrote on last edited by
                      #12

                      @Nimika

                      Well if minicom or friends dont like it either, my guess would be

                      Its brand new, you never gave anyone (user) permissions to ttyMX

                      its a monday one and broken :)

                      1 Reply Last reply
                      0
                      • jsulmJ jsulm

                        @Nimika If it still not able to open the connection then check all the connection parameters you're specifying.

                        N Offline
                        N Offline
                        Nimika
                        wrote on last edited by Nimika
                        #13

                        @jsulm
                        Well I have checked all the specifications still let me check it again.

                        @mrjj
                        What do you mean by "monday one and broken"??
                        Please clarify it thank you.

                        jsulmJ 1 Reply Last reply
                        0
                        • N Nimika

                          @jsulm
                          Well I have checked all the specifications still let me check it again.

                          @mrjj
                          What do you mean by "monday one and broken"??
                          Please clarify it thank you.

                          jsulmJ Offline
                          jsulmJ Offline
                          jsulm
                          Lifetime Qt Champion
                          wrote on last edited by
                          #14

                          @Nimika "made on Monday" :-)
                          Usually people are not fully operable on Monday after weekend and do more mistakes and produce more broken products :-)

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

                          N 1 Reply Last reply
                          1
                          • jsulmJ jsulm

                            @Nimika "made on Monday" :-)
                            Usually people are not fully operable on Monday after weekend and do more mistakes and produce more broken products :-)

                            N Offline
                            N Offline
                            Nimika
                            wrote on last edited by
                            #15

                            @jsulm
                            Lol!
                            but I think I am nowhere lacking in this regard.

                            1 Reply Last reply
                            0
                            • SGaistS Offline
                              SGaistS Offline
                              SGaist
                              Lifetime Qt Champion
                              wrote on last edited by SGaist
                              #16

                              Hi,

                              Looks like you're on linux, wouldn't that be /dev/ttyM0 ?

                              One other thing: do you have the rights to access the serial port ?

                              Interested in AI ? www.idiap.ch
                              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                              1 Reply Last reply
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                              • N Offline
                                N Offline
                                Nimika
                                wrote on last edited by
                                #17

                                Hello all thank you for your replies.
                                I sorted out my problem, its there in installation.
                                Now all ports are working fine.

                                @SGaist
                                Yeah I have used /dev/ttyM0 only.
                                Thank you!

                                1 Reply Last reply
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