Arduino Leonardo issues?

[Mike Meyer]

Hello,

I'm using FreeBSD for arduino development, and trying to use the newer
boards (most notably the Leonardo) has uncovered a problem. In
particular, this board uses the ATMega 32u4 as both the main processor
and the USB interface, rather than having a dedicated processor for
USB.

The Arduino software (in this case, actually avrdude) expects to use a
tty device to program the controller, and communicate with the
software installed on it later. This all works fine on the earlier
versions of the arduino hardware, which uses either an ftdi or ulpcom
device. With the Leonardo, this devices appears when I plug in or
reset the card, but vanishes when the card switchs from running the
bootloader to running my code. This is particularly annoying when said
code expects to communicate with my freebsd box via that usb port!

Since I don't see this behavior if I connect the Leonardo to a VM
running Linux - the /dev/tty* device is always present - I assume it's
either an issue with my FreeBSD configuration, or a problem in the
FreeBSD USB code.

Searching both google and the arduino forums don't turn up anything
useful. I checked with the maintainer of the Arduino port, and
upgraded my system from a 9.1-prerelease to the latest 9.1-releng (svn
rev 250692).  While this is better - the arduino boards now identify
themselves properly - I'm still seeing the same behavior.

Can anyone provide a pointer as to what I might look at? Or
information I can provide that might help diagnose the problem?

Thanks,
<mike