How to write bytes read from serial port to a QFile

[high_flyer]

some comments:
1. why do you allocate the serial port on the stack?
make it a member, this way you don't need to allocate it in every method, and better on the heap.
It is dengeraus to do it the way you do.
2. why don't you use QDataStream on the serial port?
3. you want to use isOpen() not open() :

if(sp.isOpen()) //here
    {
    qWarning("port still open after closing");
    }

if(sp.isOpen()) //here
    {
    qWarning("port still open after closing");
    }

To copy to clipboard, switch view to plain text mode 

It could well be that once you fix these points, the problem will go away, if not, posts again.

Another point:
You don't need to use Posix_QexSerial port, it is not portable.
Use QextSerialPort, and give the _TTY_POSIX_ flag in the make file.
This way your code will compile on windows as well.

[shamik]

why do you allocate the serial port on the stack?
make it a member, this way you don't need to allocate it in every method, and better on the heap.

how to allocate it on heap??
all i have done is made it a global member like this --->

Posix_QextSerialPort *sp = new Posix_QextSerialPort("/dev/ttyS0");

Posix_QextSerialPort *sp = new Posix_QextSerialPort("/dev/ttyS0");

To copy to clipboard, switch view to plain text mode 

but its still not working. the error is the same.

[high_flyer]

why global? why not make it a member?
And yes, use 'new' to allocate on the heap, and don't forget to use 'delete' when you don't need the object anymore (or just give it Qt object parent).