[PyQt] Using QSerialPort() instead of pyserial

Florian Bruhin me at the-compiler.org
Mon Nov 20 08:33:58 GMT 2017


On Mon, Nov 20, 2017 at 06:02:57PM +1000, Phil wrote:
> The pyserial and QSerialPort code supplied was an example of what worked and
> what didn't.

Yes, but it was code which didn't run at all, so it can't possibly be the code
you did *actually* run. Having code which actually runs makes things easier to
debug ;-)

> Anyway, after a good night's sleep and a bit of experimentation I now have a
> working solution as follows:
>         if self.serial.canReadLine():
>             data = self.serial.readLine()
>             print(data)
> I'm not sure what happens, at the moment, if there isn't and serial date to
> read

That block would just be skipped.

> One thing I haven't sorted out is how to convert a QBytearray, "data" in
> this case, to a string. The following converts the mytext QString to a byte
> array but I cannot see how to convert a byte array to a string.

(I'm assuming Python 3 here)

I usually do bytes(data).decode('ascii').
That converts the QByteArray to a Python bytes object, and then decodes that.

You could probably do str(data, encoding='ascii') too, though.

> byte = bytes(mytext, encoding='ascii')

FWIW the more idiomatic way this is usually done is  mytext.encode('ascii')


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