[libhid-discuss] Multiple duplicate interfaces?

[Charles Lepple]

On Oct 2, 2010, at 9:52 PM, Frank Rizzo wrote:

> JACKPOT!  I'm using hid_interrupt_read on ep 0x81, and getting the  
> key data 1 key at a time, in scan codes.  (Which is FINE with me!  
> I'm an old DOS programmer, I'm used to scan codes).
>
> I used usbsnoop to capture a couple of transactions, and have a  
> complete list of the scan codes for the numbers, and the <CR>.  I  
> should now have no problem whipping up a quick app that does exactly  
> what I need.

Glad that works.

At this point, the value-add of libhid is about nil, since the Usage  
path for this device is just one level deep. hid_force_open() is  
simply a wrapper for the libusb_detach_kernel_driver_np(), and  
hid_interrupt_read() is just some parameter conversion and error  
checking for libusb_interrupt_read():

http://libhid.alioth.debian.org/doc/hid__opening_8c-source.html#l00241

http://libhid.alioth.debian.org/doc/hid__exchange_8c-source.html#l00332

You could probably implement what you need in a dozen lines or so by  
calling libusb directly. I haven't tried HIDAPI that Peter mentioned,  
but it sounds like it might offer a more portable solution.