Re: [Libusb-devel] Control transfers

[Nuno S. <ns...@ed...>]

Well,

What i'm doing is:

r = libusb_control_transfer(handle, 0x40, 0x12, 0, 0, &data, 1, 1000);

Where 0x40 means that I want to send a packet from the host to the 
device (OUT), bit 7 =0, and that the requst is a vendor specific (10), 
and that it is directed to the device (00000).

My request number is 0x12 which was what I defined in the event handler 
in the device firmware.

The result is a -9 error which is  a LIBUSB_ERROR_PIPE 
<http://libusb.sourceforge.net/api-1.0/group__misc.html#ggb2323aa0f04bc22038e7e1740b2f29ef1406e98370900156484f5fe609270837>

But now, i don't know for sure if the request should be directed to the 
device, or to a determined endpoint or interface! :)

Nuno

Alan Stern wrote:
> On Mon, 6 Jul 2009, Nuno Santos wrote:
>
>   
>> Hi,
>>
>> Today I was doing some experiments on control transfers with libusb. I  
>> was setting a custom request to process on the device side,
>> and then invoking a control transfer on the host side to activate that  
>> request.
>>
>> I was getting pipe error on the transaction.
>>
>> My device is only composed by a unique custom endpoint but I was  
>> assuming the use of the default control endpoint.
>>
>> Why could this not be working? What can possibly be the most direct  
>> cause?
>>     
>
> Passing an incorrect pipe value to the library seems like the most 
> obvious possibility.
>
> Alan Stern
>
>