opening of serial port

[Nimika]

how to open the serial port outside Qt?
I have written my code in qt, it is opening but whenver I am writing or reading in that port its showing device not open.
Is there any solution??
I am using MOXA card for serial communication.

[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);

[Nimika]

@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();
}

[Nimika]

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

[jsulm]

@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);

[jsulm]

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

[Nimika]

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

[mrjj]

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

[Nimika]

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

[mrjj]

@Nimika
Ok. Just checking.

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

[Nimika]

@mrjj
Its not working with any case.

[mrjj]

@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 :)

[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.

[jsulm]

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

[Nimika]

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

[SGaist]

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 ?

[Nimika]

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!