Can QSerialPort read more than 512 bytes of data?

Question

I want to use QSerialPort to read data transmitted from a device. The device transmits a frame of 4000 data bytes each time. I try with the following simple code

Answer 1

There's no limit, but you don't necessarily receive all data in single chunk. You have to keep listening until you have the number of bytes you're waiting for (or a timeout).

void MainWindow::serialReceived()
{
    receivedData.append(serialPort->readAll());
    if(receivedData.size() >= 4000) {
       // we're full
    }
}

Answer 2

You generally have to read out the data in a loop (to ensure you get it all), here is a snippet of example code this is equivalent to your serialReceived() function, except it emits the data using emit rxDataReady(newData); to whoever is listening...

void QSerialPortReader::handleReadyRead()
{
    QByteArray newData;

    // Get the data
    while (mp_serialPort->bytesAvailable())
    {
        newData.append(mp_serialPort->readAll());
    }
    emit rxDataReady(newData);
}

edit

Although I don't do any max size checking... but that is trivial to add if you need it (i.e. just use read(..., spaceAvail) instead of readAll and then decrement spaceAvail...