How to open more than once SerialPort

erytcg

I don't understand good with this QVector. I don't know how acces to one of port and close one port not all.

mrjj

@erytcg
Hi
its a list of comports.

so v[index] gives a QSerialPort *

But you will have to answer what app does.

Currently you open all comports available on device.

Should closeSerialPort() close them all again?

to close one you would do
QSerialPort * Cur=v[0];
Cur->close();
or even
v[0]->close();

Notice i use 0 for closing the first.

So to help you , i need to understand what app does as its uncommon to open ALL comports :)

erytcg

So I need more functions, one for add aviable ports to vector and one to open specific port? For close functions I want close only one port.

mrjj

@erytcg

close functions I want close only one port.

But which one?

erytcg

Choosing from:
QList<QListWidgetItem*> items = ui->listWidget->selectedItems();
foreach(QListWidgetItem * item, items)
{
delete ui->listWidget->takeItem(ui->listWidget->row(item));
}

mrjj

Hi
if you move
QVector<QSerialPort *> v;
to the MainWindow.h (in the class)
and remove serialPort variable also!

then you could do

void MainWindow::closeSerialPort( int index)
{
QSerialPort * serialPort = v[index];
if (serialPort->isOpen())
{
serialPort->close();
..

and close the one u want with
closeSerialPort( some number)

mrjj

Oh u posted while i was writing

Can you use the row index directly to the V list ?

erytcg

yes I want to add opened COMports to ListWidget and close selected ports

mrjj

@erytcg

If there is a 1 to 1 to the V list ( please rename to comports or something :)

Then you can just use the
void MainWindow::closeSerialPort( int index)
{
QSerialPort * serialPort = v[index];
...

and call it from
foreach(QListWidgetItem * item, items) {
int index= ui->listWidget->row(item); //
closeSerialPort( index);

erytcg

Hey can you look at code? Now it's ok? :)

void MainWindow::addAvailableSerialPorts()
{
    QVector<QSerialPort *> v;
    Q_FOREACH(QSerialPortInfo port, QSerialPortInfo::availablePorts())
        {
           QSerialPort* serialPort = new QSerialPort();
           serialPort->setPort(port);
           serialPort->setBaudRate(QSerialPort::Baud9600);
           serialPort->setDataBits(QSerialPort::Data8);
           serialPort->setParity(QSerialPort::NoParity);
           serialPort->setStopBits(QSerialPort::OneStop);
           serialPort->setFlowControl(QSerialPort::NoFlowControl);
           v.append(serialPort);
        }
}
void MainWindow::openSerialPort(int index)
{         
    QSerialPort * serialPort = v[index];
    if (serialPort->open(QIODevice::ReadWrite)) 
     {
         showStatusMessage(tr("Connected to %1 : OK").arg(p.name));
     } 
    else 
    {
         QMessageBox::critical(this, tr("Error"), serialPort->errorString());
         showStatusMessage(tr("Open error"));
    }
}

mrjj

@erytcg said in How to open more than once SerialPort:

Almost but one fatal error !

void MainWindow::addAvailableSerialPorts()
{
QVector<QSerialPort *> v; <<<< This is a local var. It should be in class. windows .h. should not be defined here. only used.

So in
void MainWindow::openSerialPort(int index)
{
QSerialPort * serialPort = v[index]; <<< what v is this . it cannot be the one from addAvailableSerialPorts as that was local.

erytcg

ok I add *QVector<QSerialPort > v; to private: mainwindow.h
I have problem with close function port chooseing from list widget

mrjj

@erytcg

you need to use the row int as index

foreach(QListWidgetItem * item, items) {
int index= ui->listWidget->row(item); //
closeSerialPort( index);

erytcg

Hey it's good idea to recall to function

void MainWindow::on_connectAction_clicked()
{
    openSerialPort(ui->serialPortInfoListBox->currentIndex());
}

I think it's not MVC

mrjj

@erytcg
Hi
Im not sure what you talk about.
MVC= model, view , controller?

Is there a question ?

What you mean recall ?
Do you open it in addAvailableSerialPorts ?

erytcg

Yes I talk about model, view , controller.
I add all avaibleports to vector in addAvailableSerialPorts ()
i open in openSerialPort(int index) / index=QComboBox->currentIndex();
and close in closeSerialPort(int index) / index=QListWidget->currentRow()+1;

and all works fine I think, but if I want show received data on QCustomPlot widget.
I don't know how to convert QByteArray to QVector<double>.
My received data from qDebug() - "\x0B"
Thanks a lot for help :)

mrjj

@erytcg
Nope a list of Class * is not really MVC.

Do you really need to convert QByteArray to QVector<double> ?
Why not convert to doubles when you read and add directly to QVector instead?

Also who sends the doubles? Its not trivial to send doubles over serial as they dont map
nicely to chars and there can be a difference in byteorder and precision loss.

erytcg

I need convert because QCustomPlot func need doubles

void 	addData (const QVector< double > &keys, const QVector< double > &values, bool alreadySorted=false)
or
void 	addData (double key, double value)

mrjj

@erytcg
Yes, i understand CustomPlot wants QVector<double> but i was wondering
instead of storing all values in ByteArray and then convert, if it would be more easy
to store directly in QVector when reading them off the serial port.

Anyway, how do u know how many indexes one double will take in ByteArray ?
double is normally 8 bytes (32 bit). Do you know the byte order from the sender?

mrjj

Hi
You can test with this sample
Uses QDataStream which should be good and fast.

int main(int argc, char *argv[])
{

QByteArray byteArray;

//generate ten random float value
QVector<float> v;
for (int i =0; i < 10;++i)
{
v << 100. * qrand()/RAND_MAX;
}
//ouput vector
qDebug() << v;

//write float value to array
{
QDataStream out (&byteArray,QIODevice::WriteOnly);
foreach(float f,v)
{
out << f;
}
}

//read all float from array
QVector<float> v2;
{
QDataStream in(byteArray);
while (!in.atEnd())
{
float f;
in >> f;
v2 << f;
}
}
//ouput vector
qDebug() << v2;

return 0;
}

From here
http://www.qtcentre.org/archive/index.php/t-24744.html