Re: [pyusb-users] Errno 2 - Entity Not Found

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

On Sun, Jun 10, 2018 at 1:46 PM, Xiaofan Chen <xia...@gm...> wrote:
> On Wed, May 16, 2018 at 9:35 PM, Roland King <ro...@ro...> wrote:
>> .. my first post ..
>>
>> I have a device (Atmel running their vendor development USB stack).
>>
>> It has one configuration, one interface two alternates as they use an
>> isochronous endpoint and you can’t have that in the default configuration.
>> With the simplest example I can come up with I get ‘Errno 2  - entity not
>> found’ on any access to any endpoint on the device.
>
> I think pyusb may not work well with isochronous transfer. I have never
> tried myself.

It seems that you are not using isoc transfer but bulk so it should work.
On the other hand, I am not so sure if device understand this command.
    dev.write(0x83,'test')

And you may want to specify the time out value.

> You may want to try out using C first to see if the device works under
> plain libusb under Mac OS X.
>
> You can also try this. It claims to support isochronous transfer.
> https://github.com/vpelletier/python-libusb1


-- 
Xiaofan