On Mar 11, 3:17=A0am, Mark Piffer <mark.pif...@chello.at> wrote:
> Hi c.a.e,
> I was =A0asked to implement a bidirectional communication via USB (on an
> AVR32, which is OTG capable) between two identical devices. After some
> time of searching I couldn't even come up with a definitive answer if
> this is possible at all. Effectively this connection should work like
> a RS232, i.e. when you connect the two devices with a cable they
> should start talking to each other without an exterior trigger just by
> sensing that there is a device on the other end. While I found the HNP
> (host negotiation protocol) for OTG stacks, it remains unclear to me
> if this works with symmetrical devices. Is it possible to switch the
> stacks from device to host mode forth and back in a random pattern so
> that finally the two can connect =A0or is this even solved by the
> protocol itself? I didn't find anything about two hosts competing for
> the host role. Can anyone please enlighten me?
>
> regards,
> Mark

http://www.lvr.com/embedded_host.htm

>Hi c.a.e,
>I was  asked to implement a bidirectional communication via USB (on an
>AVR32, which is OTG capable) between two identical devices. After some
>time of searching I couldn't even come up with a definitive answer if
>this is possible at all. Effectively this connection should work like
>a RS232, i.e. when you connect the two devices with a cable they
>should start talking to each other without an exterior trigger just by
>sensing that there is a device on the other end. While I found the HNP
>(host negotiation protocol) for OTG stacks, it remains unclear to me
>if this works with symmetrical devices. Is it possible to switch the
>stacks from device to host mode forth and back in a random pattern so
>that finally the two can connect  or is this even solved by the
>protocol itself? I didn't find anything about two hosts competing for
>the host role. Can anyone please enlighten me?
>
>regards,
>Mark

Do a search for ID-pin on http://en.wikipedia.org/wiki/USB_On-The-Go

This pin tells the OTG node whether it is acting as a host or device.
	   
					
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Posted through http://www.EmbeddedRelated.com

Hi c.a.e,
I was  asked to implement a bidirectional communication via USB (on an
AVR32, which is OTG capable) between two identical devices. After some
time of searching I couldn't even come up with a definitive answer if
this is possible at all. Effectively this connection should work like
a RS232, i.e. when you connect the two devices with a cable they
should start talking to each other without an exterior trigger just by
sensing that there is a device on the other end. While I found the HNP
(host negotiation protocol) for OTG stacks, it remains unclear to me
if this works with symmetrical devices. Is it possible to switch the
stacks from device to host mode forth and back in a random pattern so
that finally the two can connect  or is this even solved by the
protocol itself? I didn't find anything about two hosts competing for
the host role. Can anyone please enlighten me?

regards,
Mark