Re: [pyusb-users] "Other error' reply to set_configuration

[Xiaofan C. <xia...@gm...>]

On Thu, Feb 25, 2016 at 1:31 PM, Xiaofan Chen <xia...@gm...> wrote:
> I am not so sure if pyusb will allow you to reach the full potential.

Since this ticker is still open.
https://github.com/walac/pyusb/issues/63

> In order to have better speed, increase the transfer size, use async I/O
> and then use an external HUB.
>
> libusb async I/O: http://libusb.sourceforge.net/api-1.0/group__asyncio.html
>
> I think you will have a good idea by reading the answers from Tsuneo here.
> +++++++++++++++++++++++
> http://www.microchip.com/forums/tm.aspx?m=417509
> ...
> ++++++++++++++++++++++
>

Another advise from another USB expert: Tim Roberts.

++++++++++++++++++
Repeating a speech I give relatively often, remember that USB traffic is
all scheduled in advance.  The whole frame is laid out ahead of time,
and the schedule is sent to the hardware.  So, the only requests that
will be present in a frame are those that were already pending when the
host controller driver started to create the schedule.  After it is
submitted, any new requests will be scheduled into the NEXT frame.

A full-speed frame can transfer about 1200 bytes.  If you expect to be
able to transfer that much data, then you must submit 1200 bytes worth
of requests before the frame begins.
++++++++++++++++++



-- 
Xiaofan