QIODevice::write: device not open

[Matthacker]

Hi

I have a problem with setting up my connection to a COM port have been stuck for awhile now hope you can help me.

Do I have to have my mbed controller connected for it to work ?

when i run my code it says:

bq.
Serial NOT Opened
error code = 1
error string = "No such file or directory"
QIODevice::write: device not open

the code I have is:
@

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "modify_scenario.h"
#include <QSerialPort>
#include <QDebug>
#include <QPushButton>
#include <QWidget>

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{

 ui->setupUi(this);

 serial = new QSerialPort(this);
 serial->setPortName("COM2");
 if(serial->open(QIODevice::ReadWrite))
 {
     qDebug("Serial Opened");
     serial->setBaudRate(QSerialPort::Baud9600);
     serial->setDataBits(QSerialPort::Data8);
     serial->setParity(QSerialPort::NoParity);
     serial->setStopBits(QSerialPort::OneStop);
     serial->setFlowControl(QSerialPort::NoFlowControl);
 }
 else
 {
     qDebug ("Serial NOT Opened");
     qDebug() << "error code = " << serial->error();
     qDebug() << "error string = " << serial->errorString();
 }

 connect(serial,SIGNAL(readyRead()),this,SLOT(serialReceived()));

@

for the connect: (serialReceived())

@
void MainWindow::serialReceived()
{
QByteArray ba;
ba = serial -> readAll();
ui->label->setText(ba);
qDebug() << ba;
}
@

and in the header I have in private slots

@

void serialReceived();
@

and in private

@

private:
Ui::MainWindow *ui;
Modify_Scenario *modify;
int counter;
QSerialPort *serial;
@

really hope you can help me :)

Regards Alex.

[kuzulis]

This means that COM2 is not exists on your PC (you can check it in Device Manager).

[Matthacker]

Hi Kuzulis

Yes that is correct, checked it already.

does that mean I have to setup a virtual com port?
and how do I do that ?

if I input my device to my computer, then my computer detects a COM port, but wanted to test it without the device.

Alex.

[SGaist]

Hi and welcome to devnet,

Do you mean that you would like to make your code run even when there's no serial port available ?

[Matthacker]

used Eltima's virtual COM port to setup a virtual port and tested it with tera term and it works now :)