From: Tim R. <ti...@pr...> - 2011-10-26 16:33:23
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Kustaa Nyholm wrote: > Hmmm, exposing my ignorance here: would a 2nd interface require an > other set of end points separate from the keyboard-HID interface? Possibly, but HID reports can also be sent via the control endpoint. Your second interface wouldn't necessarily need an endpoint. > The hardware only supports four end points and two are already in use > by the HID and two by UVC. At least that is what I think, I'm > skating on thin ice here, maybe I've got my interfaces and end points > mixed... Why does your UVC interface need two endpoints? In virtually every case, you can get by with just the isochronous endpoint. The sync endpoint is more trouble than it's worth, unless you absolutely need to maintain sync with your own UAC stream. > So we would need to use the existing HID out end point for our > control transfer, or what? Are there issues there if we just > 'extend' that mechanism. You can't have one endpoint in two interfaces. Your device has N endpoints, and the interfaces are just a way to group those endpoints. Except for the "select interface" request, interfaces are never mentioned in USB wire transfers. All addressing is done by endpoint. -- Tim Roberts, ti...@pr... Providenza & Boekelheide, Inc. |