Re: [Gumstix-users] USB Host & USB OTG application questions

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I think the current limit is hub defined, but I'm not sure. If that is
true, connecting a powered usb hub could help. My USB flash, when
connected there, does not get enumerated by the driver because of the
current limit(it says so on dmesg).

HID devices work fine, so far I've tested mouse and joystick. For some
reason, on my overo, only the OTG port supported HID devices. Could be a
driver configuration issue on the host port driver...
> Hi Victor,
> 
>   Will self powered usb hub can be connected with usb otg host like
> configuration.  And connect usb flash device on that ?
>   Will that work ?
> 
>   Will HID devices work with otg?
> 
> Thanks and regards,
> Ananth.
> 
> On Thursday 23 December 2010 04:12 PM, Victhor wrote: 
> > Em Qui, 2010-12-23 às 00:30 -0800, nordmanb escreveu:
> >   
> > > Thanks for the answer.
> > > 
> > > To be sure I well understood : 
> > > 1- I can't connect a computer to the USB Host port, because it can't exist
> > > two host at the same time.
> > >     
> > Correct.
> >   
> > > 2- I can't connect a USB flash drive to the USB OTG port, because it doesn't
> > > supply enough current.
> > >     
> > Correct.
> >   
> > > But, I'm not sure to understand these sentences:
> > >     
> > You did understand the sentences. :)
> >   
> > > Victhor Foster wrote:
> > >     
> > > > What you want to do is connect the Overo to the computer with the OTG
> > > > port, and the flash drive on the Host port. It does not work vice-versa as
> > > > :
> > > > ...
> > > > 
> > > >       
> > > Do you mean, it is impossible to connect a computer and a USB flash drive at
> > > the same time even if I switch the ports?
> > > Actually, I didn't really understand the "It doesn't work vice-versa" (sorry
> > > I'm French ;) )
> > > 
> > > If I consider the OVERO Fire COM as a computer (it has an embedded OS, so
> > > it's not ridiculous to think like this), couldn't I plug the USB Flash drive
> > > on the USB Host port and cofigure the USB OTG as a device and plus the
> > > computer?
> > > 
> > > Am I wrong?
> > > 
> > > Thanks again.
> > > 
> > > Victhor Foster wrote:
> > >     
> > > > USB OTG port can be configured as host or device. The kernel that ships
> > > > with the stock Fire is configured to use the OTG port as a host only, so
> > > > you'll have to change that setting. The USB Host port, as its name says,
> > > > can only be used as a host. What you want to do is connect the Overo to
> > > > the computer with the OTG port, and the flash drive on the Host port. It
> > > > does not work vice-versa as:
> > > > 1. The host port does not support operation in device mode, thus you
> > > > can't connect the Overo to a computer with this port;
> > > > 2. The OTG port has a current limit of 100 mA, which makes it unsuitable
> > > > for use with a flash drive(I've tried).
> > > >       
> > > > > Hi!
> > > > > 
> > > > > I would like to make an extension card to connect to the OVERO Fire COM
> > > > > (OFC). This card would use the USB Host and the USB OTG buses.  One of
> > > > > these
> > > > > connections would be used to talk with a computer and the other one with
> > > > > a
> > > > > standard USB flash drive. Sadly, I don't really know which connections
> > > > > will
> > > > > match the best with each of them.
> > > > > 
> > > > > Let me explain.
> > > > > I read that the USB OTG is made to allow two peripherals to talk to each
> > > > > other without requiring a computer. So, I think it would be better to
> > > > > connect it with the USB flash drive.
> > > > > 
> > > > > Furthermore, I read that with the standard USB protocol, the computer
> > > > > have
> > > > > to be the host. The second USB connection, however, make the OFC be the
> > > > > host. 
> > > > > I didn't find any information about two hosts talking to each others at
> > > > > the
> > > > > same time, but I'm almost sure it can't be possible anyway. So, I can't
> > > > > connect a computer to this connection, then I also have to use the USB
> > > > > OTG.
> > > > > 
> > > > > But I couldn't connect the USB flash drive to the USB Host because it's
> > > > > not
> > > > > an OTG. The question would be: what could we connect on this connection?
> > > > > 
> > > > > Maybe I made a mistake and I didn't really understand how it works. If
> > > > > that
> > > > > so, I'll be glad to have some explanation.
> > > > > 
> > > > > Thanks! And merry Christmas!
> > > > >         
> > > > 
> > > > 
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> > > > 
> > > >       
> > > -- 
> > > View this message in context: http://old.nabble.com/USB-Host---USB-OTG-application-questions-tp30512833p30520056.html
> > > Sent from the Gumstix mailing list archive at Nabble.com.
> > > 
> > > 
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> to consolidate database storage, standardize their database environment, and, 
> should the need arise, upgrade to a full multi-node Oracle RAC database 
> without downtime or disruption
> http://p.sf.net/sfu/oracle-sfdevnl
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