Problems with external 5V supply
hakan.pm.berg at gmail.com
Wed Apr 4 04:51:49 UTC 2012
Patrik: I have tried only USB2 devices. Mouse and keyboard direct and also
via dongle. I have also used an 8 GB memory-stick, and it worked fine as
well. So high-speed USB works, but I have not tried Ultra-Speed.
Jacques: Regarding OTG power detection, I suppose you are rigth. I probably
means that the detection somehow fails.
Since I heard something about wardware error causing the USB problems I
asked a guy at ST-Ericsson and got an explanation. The ground wiring for
the power and USB parts was not done properly on the Snowball, causing
ground level noise. This could have a huge impact when connecting and
disconnecting a cable at the OTG port if current goes in either direction
of the +5V lead, since that also means the same current goes through the
Den 2 april 2012 17:00 skrev Richard Curnow <richard.curnow at stericsson.com>:
> Hi Kalle,
> On 04/02/2012 03:47 PM, Kalle Vahlman wrote:
>> But yes, there's a funny discrepancy on behavior with OTG power and
>> "wall power" wrt bootup, mainly due to flashing I guess.
> OK, that makes sense.
>> Another way to reset the board is to press the blue button for 10s
>> (yes, that long) to shut it down and then press it again to boot up.
> That works for me. Apart from the delay, I think it's preferable, because
> the switch feels a lot more resilient than the other one.
> users mailing list
> users at igloocommunity.org
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