[jack_umidi] baud rate when writing MIDI messages from USB to jack_umidi

[Marcel Bonnet]

Em qua, 29 de mai de 2019 17:58, Hans Petter Selasky <hps at selasky.org>
escreveu:

> On 2019-05-29 16:52, Marcel Bonnet wrote:
> > On Wed, 29 May 2019 at 11:27, Hans Petter Selasky <hps at selasky.org>
> wrote:
> >
> >> On 2019-05-29 16:15, Marcel Bonnet wrote:
> >>> Hello.
> >>>
> >>> I'm making a MIDI controller with Arduino UNO and I though somebody
> could
> >>> help me on clarify if I should set a specific baud rate when writing
> MIDI
> >>> messages from Arduino (from USB port) that are target to jack_umidi.
> >>>
> >>> I realize that whem I'm writing chars (debug messages) they are
> >> interpreted
> >>> as random MIDI notes. But when I turn debug off and write something
> like:
> >>>
> >>>         Serial.write(0x90);
> >>>         Serial.write(0x30);
> >>>         Serial.write(0x7F);
> >>>         Serial.flush();
> >>>
> >>> no MIDI message is received (I used jack_midi_dump to check, it is
> >> empty) .
> >>>
> >>> So I'm not asking about Arduino itself, but maybe it is something
> related
> >>> to the baud rate?
> >>>
> >>
> >> The USB protocol use a classification byte. Every USB MIDI command is
> >> always 4-bytes long.
> >>
> >> Regular MIDI is using 64000 baud I think.
> >>
> >> --HPS
> >>
> >>
> > Thanks a lot HPS!
> >
> > BTW, I looked at
> > http://www.gweep.net/~prefect/eng/reference/protocol/midispec.html : it
> > states 31250 baud for MIDI.
> >
> > I'm opening the arduino USB device as:
> > $ jack_umidi -S -B -C /dev/cuaU0
> >
> > In this case, 9600 baud is too slow? Should I set to 31250 next time?
> >
> > Thanks in advance,
> >
>
> I've never tested jack_umidi like this :-)
>
> Maybe you'll need to patch it to set the baud rate.
>
> --HPS
>

Now I see why it was not working as expected.

And this discussion led me to another approach: I'll write a program to
read the serial USB (/dev/cuaU0) from Arduino (I can use the term library
to sync the baud rate) and dispatch the data as a jack client to the MIDI
device and/or applications involved. ;-)

Thank you, HPS.

>