[libhid-discuss] Report Description Question (Not Matching lsusb)

[Charles Lepple]

On Oct 2, 2008, at 8:36 PM, Christopher Moore wrote:

> Hello,
>
> I'm trying to get some output from hid_dump_tree and I can't seem  
> to get
> anything meaningful out of it.  For example, in one of the older posts
> on this mailing list, I managed to see output like the following:
>
> TRACE: hid_dump_tree(): iterating the parse tree for USB device  
> 001/003[0]...
> parse tree of HIDInterface 001/003[0]:
>   path: 0x00010009.0x00010033; type: 0x80
>   path: 0x00010009.0x00010034; type: 0x80
> ...
>
> while, I can only recieve this:
>
> TRACE: hid_reset_parser(): resetting the HID parser for USB device  
> 002/005[3]...
>   TRACE: hid_prepare_parser(): dumping the raw report descriptor
>   TRACE: hid_prepare_parser(): 0x000: 0x05

Please try the C test_libhid.c program first - the Python interface  
is newer, and may have hidden bugs.

> -------------------
>
> the code being used (Python):
>
> hid_set_debug(HID_DEBUG_ALL)
> hid_set_debug_stream(sys.stderr)
> hid_set_usb_debug(0)
>
> ret = hid_init()
> if ret != HID_RET_SUCCESS:
>   sys.stderr.write("hid_init failed with return code %d.\n" % ret)
>
> hid = hid_new_HIDInterface()
> matcher = HIDInterfaceMatcher()
> matcher.vendor_id = 0x13b1
> matcher.product_id = 0x001d
>
> ret = hid_force_open(hid, 3, matcher, 3)
> ret = hid_dump_tree(sys.stdout, hid);
>
> ---------------------
>
> I'm after Interface #3 (the hid device).


I would also take a look at the hidwrap.py high-level wrapper around  
the SWIG-generated code. The hidwrap.py interface is more object- 
oriented, and hides some of the C heritage of the code.

-- 
Charles Lepple