Issues 179505

[Hans Petter Selasky]

On 06/21/13 20:17, Mike Meyer wrote:
> Sorry 'bout the extra emphasis there.
>
> Anyway, the problem is not *simply* the sketch code. It could be
> something in the Arduino bootloader violating a USB spec that Linux
> doesn't care about and FreeBSD does. But mucking about with the user
> code on the Arudino (i.e. - sketches) doesn't change anything: I get
> the same behavior whether it's running a trivial Blink demo (pretty
> much no libraries used at all) or a complete interactive shell:
>
> It works as expected when connected to Linux running on a VBox VM,
> with the umodem device always being present.
>
> If I don't connect it to the VM, the umodem device appears when the
> board is plugged in or reset, then disappears before the sketch starts
> running.

Hi,

I think I have one of these devices at work. I can have a look if I have 
time next week. Possibly the Arduino needs a fix. Look for so-called 
spurious VBUS pullup toggling in the software of the Arduino.

--HPS