[solved] QSerialPort error - "is a directory"

beakie

This code gives an error of "Is a directory" when open() is called. I assume it's permissions or something but I can't find a single instance ANYWHERE online of someone else getting this error?

[code]
#include <QCoreApplication>
#include <QDebug>
#include <QtSerialPort/QSerialPort>
#include <QtSerialPort/QSerialPortInfo>

int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
QSerialPortInfo serialPortInfo("/dev/ttyUSB0");
QSerialPort serialPort(serialPortInfo);

QByteArray byteArrayRequest;
byteArrayRequest.resize(2);
byteArrayRequest[0] = 0x01;
byteArrayRequest[1] = 0x01;

if (serialPort.open(QIODevice::ReadWrite))
{
    serialPort.setBaudRate(QSerialPort::Baud38400);
    qDebug() << "Writing\n";
    serialPort.write(byteArrayRequest);
    serialPort.close();
}
else
{
    qDebug() << serialPort.errorString();
    qDebug() << "Problem opening port\n";
}

return a.exec(&#41;;

}

[/code]

Can anyone please advise?

Thanks

SGaist

Hi,

What does ls -la /dev/ttyUSB0 return ?

beakie

[quote author="SGaist" date="1393630095"]What does ls -la /dev/ttyUSB0 return ?[/quote]

If the device IS NOT plugged in:
ls: cannot access /dev/ttyUSB0: No such file or directory

If the device IS plugged in:
crw-rw---- 1 root uucp 188, 0 Mar 1 21:27 /dev/ttyUSB0

SGaist

Are you member of the uucp group ?

beakie

[quote author="SGaist" date="1393714479"]Are you member of the uucp group ?[/quote]

I have run my code as root.

beakie

OK, so I figured I must be referencing the port incorrectly.

This post was useful -> http://qt-project.org/forums/viewthread/28942

I changed the hardcoded reference to /dev/ttyUSB0 in my code and loaded it in the same way as the posts do and it worked fine!

Thanks :)

SGaist

You're welcome !

Since you have your serial port talking now, please update your thread title prepending [solved] so other forum users may know a solution has been found :)