Main Site Documentation

Feature Report on USB Client


#1

Hello,
I have created a custom HID device which uses an Interrupt In endpoint to the host. The report descriptor specifies an Input and “feature report”.

  1. How can I access the raw data on the device side. The USB host API in the .net micro framework has the capability, but not the client as far as I can see.

  2. How can I see the Feature report descriptors sent from the host in the device side, since I cant see the raw data of the control pipe. That is the host updates the HID Feature report, and the device should be able to see the update.

I am currently using .net micro framework 4.1 / 4.2, with a GHI electronics Cobra board. I have found plenty of documentation to access the raw data on the host side and the feature report, but not the client/device side.

Any help would be appreciated.

Thanks,

Tim


#2

The question is not very clear are you using USB client or USB Host on your FEZ? I think Client but not sure.

Now, on client side, what are you trying to accomplish at the end?


#3

Correct, I have created, a custom HID USB Client.

The USB client design only uses a “interrupt in” endpoint, and the host side communicates to the Client
via HID feature reports Example below:

db 00ah,011h,002h ; USAGE -
db 0xxh,081h ; REPORT_ID (0x81)
db 0xxh,008h ; REPORT_SIZE (8)
db 095h,001h ; REPORT_COUNT (1)
db 0b1h,003h ; FEATURE (Cnst,Var,Abs)

Note: The host does not use output reports.

To clarify: How can I access the Feature report updates on the client side?
Also, it will be required to access the raw data on the client side. Is there a way to do so?

Thanks for your help.


#4

Why not use CDC or stream? Should be easier.


#5

Thanks for the reply, I am using the “CreateUSBStream (writeEndpoint, 0)” Is that what you meant by “stream”?

I do not have the choice as far as the host, this is an emulation of another device, and will be unable to change the requirements. (input report and feature report).

CDC is the serial to USB interface? Can that be used for HID USB communication?


#6

I do not think you can use EP0, that is the control EP, which is used internally by the system.


#7

Thanks,

Is there a “GetFeatureReport” method for the client? or is there currently no support.

Also, what is the endpoint ATTRIBUTE for data for? MS.Configuration.Endpoint.ATTRIB_Data

I am interested in paid support, does TinyCLR, or GHI electronics offer this?
Or how would I go about requesting a purchased custom API for the FEZ Cobra system, or is there a board that allows access to EP0?


#8

I think GetFeatureReport is part of HID, not a generic USB feature.

Yes GHI offers consulting service. Please email/phone us with your your needs. Please include information about the device you are trying to emulate. The more we understand what you need the easier it is ti implement, which will save you some money at the end.