Hey,

I used the OTG port to connect the GPRS modem and it did not work.

I did ground pins 4 and 5 of the OTG USB on the tobi board to ensure the gumstix acts as the master. This is because I did not have the OTG cable.

Regarding power, I think the only power is consumed by the connection of the USB device to my device only as the GPRS device itself is external powered. So, I dont think I am using more than 100mA either.

Bootlog is as follows:

[    4.828887] usbcore: registered new interface driver usbserial     
[    4.835174] USB Serial support registered for generic                       
[    4.840606] usbcore: registered new interface driver usbserial_generic      
[    4.847473] usbserial: USB Serial Driver core                               
                                                                               
reading boot.scr                                                                
[    4.972534] USB Serial support registered f)

Is there anything which I missed?

Thanks.

Chinab


On Fri, Oct 28, 2011 at 4:27 PM, Steve Modica <modica@small-tree.com> wrote:
The pins for using Full Speed mode are not all connected.  Further, the driver does not have the code to drive the chip in that mode either (it's different pins)

Steve

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.
>
> Alexander
>
>
> On Fri, Oct 28, 2011 at 2:17 PM, Chinab Chugh <chinab91@gmail.com> wrote:
>> 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
>> [http://gumstix.org/getting-started.html]
>> 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
>> hub?
>> Thanks a lot for helping! I am a bit lost so will appreciate any
>> suggestions.
>> Chinab
>
>
> --
> Alexander Thomas
> Research Engineer
>
> eSATURNUS NV
> T +32 16 40 12 82
> M +32 477 51 63 62
> http://www.esaturnus.com
>
> ------------------------------------------------------------------------------
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--
Steve Modica
CTO -  Small Tree Communications
www.small-tree.com







------------------------------------------------------------------------------
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demand for specialized networking skills is growing even more rapidly.
Take a complimentary Learning@Cisco Self-Assessment and learn
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http://p.sf.net/sfu/cisco-dev2dev
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Take care and enjoy the day!

Chinab :) :D :P