On Oct 28, 2011, at 7:35 AM, Alexander Thomas wrote:
> Hi Chinab,
> There is no way at all to get the USB host port to work in anything
> but high-speed mode. Stop trying to do it, you'll only waste your time
> (been there, done that). Although the OMAP35xx does support USB 1.1 on
> the host port, it requires a separate USB 1.1 PHY chip which is not
> present on the Gumstix boards.
> The good news is that the OTG port in host mode does support low- and
> full-speed. But if your device draws more than 100mA, you will still
> need the powered hub.
> On Fri, Oct 28, 2011 at 2:17 PM, Chinab Chugh <email@example.com
>> Hey All,
>> I have a overo earth+tobi interface running 2.6.39 kernel. I want to use a
>> 2.0 USB 12MBPS GPS modem device with my gumstix as a host.
>> I tried to connect it to the USB host, but it never worked directly unless
>> it was connected via a USB hub (non-external powered).
>> To understand why this is the case, I read on the Gumstix website
>> that: Gumstix "Host" = USB High speed (480Mbit/s ONLY). You will need a hub
>> to connect to most USB -> Serial adapters
>> But why is it '480Mbps ONLY'? The OMAP35x Technical Manual mentions that the
>> USB host subsystem complies with USB 2.0 12 or 1.5 or 480 Mbps signals. Also
>> it states that it complies with both EHCI and OHCI.
>> So how do I get my Gumstix to be configured to making such a USB connection
>> to work... I did try to add the OHCI module in the kernel but it did not
>> help. Is there any pin on the omap or a register value which I can use to
>> ensure that OHCI is used instead?
>> It is interesting that many people provide the solution as using a USB hub.
>> I know that is a solution, but I am a bit confused as to why I have to use
>> it in the first place...
>> Furthermore, I don't mind using the OTG port - will it work there without a
>> Thanks a lot for helping! I am a bit lost so will appreciate any
> Alexander Thomas
> Research Engineer
> eSATURNUS NV
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