[sdiy] usb keyboard protocol

[johnspeth at yahoo.com]

I recently finished building and coding a USB/MIDI converter so I paid my dues in learning all that stuff.  My device is a classic and simple one that provides basic MIDI over USB functionality.

You need the USB MIDI document which is a subclass document of the Audio class doc.  Most of the difficult stuff for USB/MIDI is in getting the descriptors correct for proper enumeration.  The data conveyance part is straightforward using one bulk in and one bulk out endpoint.  There is one key part of the USB/MIDI doc that explains how to encode and decode the MIDI data.  It's a very short part of the doc but it is key to understanding the data part of the interface.  You'd miss it if you paged through the paper quickly.  You can't explain it much simpler than what's there so I doubt you'll find another reference but please search and let us know if you do find it.

JJS


----- Original Message ----
> From: Mark Rivera <marr at lumin.us>
> To: Synth DIY <synth-diy at dropmix.xs4all.nl>
> Sent: Wed, November 11, 2009 2:34:40 PM
> Subject: [sdiy] usb keyboard protocol
> 
> Has anyone worked with USB keyboards before? I'm trying to find a
> concise document or book or chapter that explains the quickie version
> of the protocol (besides the USB/HID docs). I'd like to be able to use
> a keyboard as the input device for what amounts to a midi terminal.
> 
> Mark
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