Searching \ for '[EE] USB multiplexer' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=usb+multiplexer
Search entire site for: 'USB multiplexer'.

Exact match. Not showing close matches.
PICList Thread
'[EE] USB multiplexer'
2008\02\01@064430 by Vasile Surducan

face picon face
Hi,

I need to build an 1 to 4 USB multiplexer. Does anyone did it before and tested
any analog multiplexer under  high speed (480Mbps) or at least under
full speed (12Mbps)?
I need to connect four identical web camera using the same software
for aquiring images.

thx,
Vasile

2008\02\01@073004 by Chris Emerson

flavicon
face
On Fri, Feb 01, 2008 at 01:44:08PM +0200, Vasile Surducan wrote:
> I need to build an 1 to 4 USB multiplexer. Does anyone did it before
> and tested any analog multiplexer under  high speed (480Mbps) or at
> least under full speed (12Mbps)?  I need to connect four identical web
> camera using the same software for aquiring images.

I may be misunderstanding, but it sounds like what you want is a USB 2.0
hub.

Cheers,

Chris

2008\02\01@073822 by Xiaofan Chen

face picon face
On Feb 1, 2008 7:44 PM, Vasile Surducan <spam_OUTpiclist9TakeThisOuTspamgmail.com> wrote:
> I need to build an 1 to 4 USB multiplexer. Does anyone did it before and tested
> any analog multiplexer under  high speed (480Mbps) or at least under
> full speed (12Mbps)?
> I need to connect four identical web camera using the same software
> for aquiring images.

A USB 2.0 Hub?

Xiaofan

2008\02\01@073925 by Vasile Surducan

face picon face
On 2/1/08, Chris Emerson <.....picKILLspamspam@spam@nosreme.org> wrote:
> On Fri, Feb 01, 2008 at 01:44:08PM +0200, Vasile Surducan wrote:
> > I need to build an 1 to 4 USB multiplexer. Does anyone did it before
> > and tested any analog multiplexer under  high speed (480Mbps) or at
> > least under full speed (12Mbps)?  I need to connect four identical web
> > camera using the same software for aquiring images.
>
> I may be misunderstanding, but it sounds like what you want is a USB 2.0
> hub.

No-no. A multiplexer not a hub. With a hub you can't use the same
software for N identical USB devices. Will stuck the software.

2008\02\01@075551 by Chris Emerson

flavicon
face
On Fri, Feb 01, 2008 at 02:39:03PM +0200, Vasile Surducan wrote:
> On 2/1/08, Chris Emerson <picspamKILLspamnosreme.org> wrote:
> > On Fri, Feb 01, 2008 at 01:44:08PM +0200, Vasile Surducan wrote:
> > > I need to build an 1 to 4 USB multiplexer. Does anyone did it before
> > > and tested any analog multiplexer under  high speed (480Mbps) or at
> > > least under full speed (12Mbps)?  I need to connect four identical web
> > > camera using the same software for aquiring images.
> >
> > I may be misunderstanding, but it sounds like what you want is a USB 2.0
> > hub.
>
> No-no. A multiplexer not a hub. With a hub you can't use the same
> software for N identical USB devices. Will stuck the software.

So you're trying to work around a particular programme which can't cope
with more than one webcam plugged in?

There's no reason well-written software can't make use of multiple
identical USB devices at the same time.

Cheers,

Chris

2008\02\01@080140 by Marc Nicholas

picon face
On Feb 1, 2008 7:39 AM, Vasile Surducan <.....piclist9KILLspamspam.....gmail.com> wrote:
> On 2/1/08, Chris Emerson <EraseMEpicspam_OUTspamTakeThisOuTnosreme.org> wrote:
> > On Fri, Feb 01, 2008 at 01:44:08PM +0200, Vasile Surducan wrote:
> > > I need to build an 1 to 4 USB multiplexer. Does anyone did it before
> > > and tested any analog multiplexer under  high speed (480Mbps) or at
> > > least under full speed (12Mbps)?  I need to connect four identical web
> > > camera using the same software for aquiring images.
> >
> > I may be misunderstanding, but it sounds like what you want is a USB 2.0
> > hub.
>
> No-no. A multiplexer not a hub. With a hub you can't use the same
> software for N identical USB devices. Will stuck the software.

Is that actually a legal implementation of USB?

-marc

2008\02\01@082111 by Hazelwood Lyle

flavicon
face
> > > > I need to build an 1 to 4 USB multiplexer. Does anyone
> did it before
> > > > and tested any analog multiplexer under  high speed
> (480Mbps) or at
> > > > least under full speed (12Mbps)?  I need to connect
> four identical web
> > > > camera using the same software for aquiring images.
> > >
> > > I may be misunderstanding, but it sounds like what you
> want is a USB 2.0
> > > hub.
> >
> > No-no. A multiplexer not a hub. With a hub you can't use the same
> > software for N identical USB devices. Will stuck the software.
>
> Is that actually a legal implementation of USB?

USB is designed to deal with devices being connected or
disconnected at any time. HOWEVER.. that connection begins
an enumeration process that is a bit lengthy. Also, some
OS's are better at dealing with frequent reconnects than others.

Which leads to the next question: How fast are you planning on
switching this "multiplexer"? And after how many switching
events will your OS or software get buggy and give up?

It would make more sense to switch your video signals before
they are digitized, but most webcams are probably straight to
digital, so that option probably won't go.

There must be a better way than multiplexing.

Lyle

2008\02\01@082624 by Tamas Rudnai

face picon face
> Is that actually a legal implementation of USB?

Of course not - it could be implemented as a very special hub though. All
the descriptors are coming from the first device only, OUT and SETUP packets
goes to all devices while IN packets are only from the first one - not sure
if that can be done? Maybe not that easy, have to send the ACK to the device
otherwise it can be stuck in a state... Maybe the hub can contain a host
controller and acts like a device on the other side, so it collects all the
descriptors and puts them together as one fat composite device - but then
the host machine will see them as separate devices, same as it was used then
in a normal hub, so there is no advantage over it.

I think to modify that software to handle more than one device, or write one
with an identical functionality is easier and more robust solution here. If
this is not possible then having many machines (even virtual machines)
running the software dealing with only one device by each, and a script
(scripting language or AutoIt or something like that) so that the task can
be done parallel and synchronized if necessary...

Tamas


On Feb 1, 2008 1:01 PM, Marc Nicholas <geekythingspamspam_OUTgmail.com> wrote:

{Quote hidden}

> -

2008\02\01@090728 by Xiaofan Chen

face picon face
On Feb 1, 2008 7:44 PM, Vasile Surducan <RemoveMEpiclist9TakeThisOuTspamgmail.com> wrote:
> Hi,
>
> I need to build an 1 to 4 USB multiplexer. Does anyone did it before and tested
> any analog multiplexer under  high speed (480Mbps) or at least under
> full speed (12Mbps)?
> I need to connect four identical web camera using the same software
> for aquiring images.

Google finds these from the leading vendors (ADI and Maxim).
www.analog.com/IST/SelectionTable/?selection_table_id=242
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/5233

Xiaofan

2008\02\01@094352 by Bob Axtell

face picon face
Vasile Surducan wrote:
> Hi,
>
> I need to build an 1 to 4 USB multiplexer. Does anyone did it before and tested
> any analog multiplexer under  high speed (480Mbps) or at least under
> full speed (12Mbps)?
> I need to connect four identical web camera using the same software
> for aquiring images.
>
> thx,
> Vasile
>  
I'm skeptical about semiconductor switches doing this reliably. I'd use
tiny latching relays at 12V.

--Bob

2008\02\01@124629 by Vasile Surducan

face picon face
On 2/1/08, Hazelwood Lyle <spamBeGoneLHazelwoodspamBeGonespammfgnc.com> wrote:
{Quote hidden}

There isn't so far. Imagine four identical devices (not OEM ) which
can be manufactured by any producer. Leak of documentation.
Proprietary software. However I need to use four devices and I can't
even I have 6 USB ports...Why the hell they are manufacturing
computers with 6 or 8 USB ports if can't be used properly ?

2008\02\01@124655 by Vasile Surducan

face picon face
On 2/1/08, Xiaofan Chen <TakeThisOuTxiaofancEraseMEspamspam_OUTgmail.com> wrote:
> On Feb 1, 2008 7:44 PM, Vasile Surducan <RemoveMEpiclist9spamTakeThisOuTgmail.com> wrote:
> > Hi,
> >
> > I need to build an 1 to 4 USB multiplexer. Does anyone did it before and tested
> > any analog multiplexer under  high speed (480Mbps) or at least under
> > full speed (12Mbps)?
> > I need to connect four identical web camera using the same software
> > for aquiring images.
>
> Google finds these from the leading vendors (ADI and Maxim).
> www.analog.com/IST/SelectionTable/?selection_table_id=242
> http://www.maxim-ic.com/quick_view2.cfm/qv_pk/5233


That's looking good. thx.

2008\02\02@025524 by Cedric Chang

flavicon
face
{Quote hidden}

Vasile
Are you planning to use these for full speed ?
Cedric

More... (looser matching)
- Last day of these posts
- In 2008 , 2009 only
- Today
- New search...