Total power from USB
tiagomnm at gmail.com
Sun Apr 25 04:52:15 EDT 2010
It's an Iomega 160GB, which has a seagate drive inside, not sure which one.
As I said in the previous e-mail, the drive works fine, it just doesn't do
so when I have other devices plugged, which I understand may be normal given
the total power I am pulling of the XO 1.5. I just wanted to know if you
were are of that(and that SD cards take a toll on that power), because it
could be some kind of design flaw that wasn't detected. If it is a known
"problem", then it's all good :)
On Sat, Apr 24, 2010 at 11:19 PM, Paul Fox <pgf at laptop.org> wrote:
> tiago wrote:
> > I forgot to mention that's not my case since even if I plug the two USB
> > it still can't power up.
> on either XO model the extra cables won't make a difference -- all the
> power (1A available total) is available to any port. does your drive
> work on an XO-1? do you have power consumption specs for your drive?
> > Best regards,
> > Tiago
> > On Sat, Apr 24, 2010 at 7:42 PM, Sameer Verma <sverma at sfsu.edu> wrote:
> > > On Sat, Apr 24, 2010 at 4:55 PM, Tiago Marques <tiagomnm at gmail.com>
> > > > Hi all,
> > > > I've ran into something on the 1.5 B2 I have here, which I'm in
> doubt if
> > > may
> > > > or may not be relevant for OLPC's hardware people(it seems not), so
> > > > reporting it anyway.
> > > > All three USB ports can deliver enough power to an USB 2.5" HDD, no
> > > problem.
> > > > They cannot in the following conditions:
> > > > - An extra SD card is plugged in
> > > > - Another USB device is plugged in one port, even one of lower
> > > like a
> > > > flash drive. (sometimes it only takes one, sometimes it takes two,
> > > card
> > > > power also seems to be an issue)
> > > > When I try to plug in the 2.5" HDD, it doesn't have enough power to
> > > spindle
> > > > at enough speed and sits there trying to start itself.
> > > > When plugging in an USB device or SD card after the 2.5" HDD is
> > > > working, it suffers a loss of power and enters the restarting state.
> > > is
> > > > true if the SD card is plugged in instead(with another USB device
> > > present),
> > > > which suggests me that the power is shared.
> > > > No other plugged devices seem to be rendered temporarily
> unaccessible due
> > > to
> > > > the power failure on the high power device.
> > > > Best regards,
> > > > Tiago
> > > > _______________________________________________
> > > > Devel mailing list
> > > > Devel at lists.laptop.org
> > > > http://lists.laptop.org/listinfo/devel
> > > >
> > >
> > > I see a similar issue with a Lacie drive on my Dell desktop. This
> > > drive actually comes with a cable that has two USB cables to draw
> > > power from two ports. With two ports, the platter spins without any
> > > problem. With one port, the disk clicks on the Dell.
> > >
> > > On a XO-1 G1G1, XO-1.5 B2 and XO-1.5 C2 I am able to power the same
> > > drive via one port only both with a SD card and without a SD card. The
> > > issue may very well be the USB drive power draw. I am using a LACIE
> > > Design by FA Porsche http://bit.ly/9HD5uI
> > >
> > > This will be important for XS-on-XO scenarios, where we would
> > > piggyback the /library partition onto an external drive.
> > >
> > > cheers,
> > > Sameer
> > >
> > > --
> > > Dr. Sameer Verma, Ph.D.
> > > Associate Professor, Information Systems
> > > Director, Campus Business Solutions
> > > San Francisco State University
> > > http://verma.sfsu.edu/
> > > http://cbs.sfsu.edu/
> > > http://is.sfsu.edu/
> > >
> > part 2 text/plain 129
> > _______________________________________________
> > Devel mailing list
> > Devel at lists.laptop.org
> > http://lists.laptop.org/listinfo/devel
> paul fox, pgf at laptop.org
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