qt serial communication, readyRead not emitted

Question

I'm communicating with a CameraLink camera using the CameraLink internal virtual COM-Port. I wrote the following code:

serial=new QSerialPort(this);
connect(serial,SIGNAL(readyRead()),SLOT(readFPN()));
serial->setPortName(comPort);
serial->setBaudRate(QSerialPort::Baud9600);
serial->setStopBits(QSerialPort::OneStop);
serial->setParity(QSerialPort::NoParity);
serial->open(QIODevice::ReadWrite);

QString comm=QString("r gwbr\r"); //read red channel gain
serial->write(comm.toUtf8(),comm.size());

QString comm=QString("r gwbb\r"); //read blue channel gain
serial->write(comm.toUtf8(),comm.size());

... more serial commands

The readFPN function does nothing by now except appending the data read to a QByteArray:

void ts4control_calibrationdialog::readFPN()
{
    resp+=serial->readAll();
}

But the readFPN-function is never called. I set a breakpoint and the program steps over the write commands without calling the callback. The general communication with the device works in a COM-Port-terminal using the above settings.

What do I have to change to have the signal emitted? Or how can I find out why it isn't working? Any debugging-ideas?

Answer 1

完成编写串行命令后，请使用QSerialPort::flush()写入基础串行端口。

Answer 2

I had the same problem, read this, read a couple of other useless (for my case ) things, and then it finally ocurred to me, to look at one of the examples Qt provides abour QSerialPort (called terminal), in wich i saw the "connect" line was written differently Instead of:

connect(serial,SIGNAL(readyRead()),SLOT(readFPN()));

It would be:

connect( serial, &QSerialPort::readyRead, this, &ts4control_calibrationdialog::readFPN );

I'm pretty much a noob, but i hope this works for you!