Minilab mk II - USB transfer always 64 bytes

[tomasb]

Hi,

During some MIDI development using Arturia MiniLab mk II I have noticed, that data are always sent as 64 byte USB packet, even where there is only one MIDI Event to send.
Packet is then filled with zeroes, but anyway, this dummy events are overhead that has to be processed by the host application as it have to loop over all of them, even that it doesn't contain any information to process. According to my experience sending only valid events without need to pad whole packet is non problematic, so I was bit surprised to see this.

Is this something according to USB MIDI specs, or is it a small firmware bug?
In case of a bug, could it be fixed in some next firmware update?

Also could one change MIDI out channel of keyboard without app runing, i.e. MiniLab is running as standalone MIDI keyboard?
I'm trying to pres and hold shift and then pressing keys according to blue print over them, but notes are still transmitted on channel 1 only. Pads are transmitting on channel 10.
It does work in other than preset 1 (Analog Lab)

Thanks.
T.

[Germain.arturia]

Hi TomasB,
really interesting one.
Sure improvement could be done for this part.
i'll report this to dev colleagues, but don't really now what can be done for now.
thanks for your understanding,

best,

[tomasb]

Thanks for your reply.

From code perspective I don't expect huge issue. It seems just that wrong number is set to endpoint while sending it to USB peripheral. But to be honest, I haven't seen your code.
In any case fix would be welcome and patience is only approach in this case.

T.

[tomasb]

Hi, do we have any news on this? Now it seems to be bigger issue, as buffer for MIDI events need to be huge.

[Germain.arturia]

HI Tomasb,
sorry i have no news for this for now. But i can confirm this one is now known by the dev team, and will be considered on next minilab mkII update . Sorry i can't say more about this.