[libhid-discuss] Report Descriptors

[Charles Lepple]

Wesley Revens wrote:
> The (nulls) in the report descriptor lsusb ouput and the hid_dump_tree
> data look strange. I believe that the device firmware is incorrect
> however is there anything else that I could be doing wrong?

'lsusb' is a bit more authoritative on what is broken and what isn't - the
"usage paths" ending in 0x00000000 are an unresolved problem in the libhid
HIDParser module, and they generally occur whenever a byte in a report is
represented by a range of usage codes (as seen in keyboards, for instance,
where they specify usages by a minimum and maximum usage code).

I don't know what else to tell you, except that there are a few tools
freely available for Windows (binary only, though) that will let you
construct a HID descriptor that you could load into some test firmware to
see if it is a build problem.

Can you explain a little more about the device firmware? Is it being
written in-house? Has it been tested with Windows or another USB stack?

-- 
Charles Lepple
clepple at ghz.cc