USB Hub on Beaglebone Black.

[anfederman@comcast]

Has anyone got more than two USB devices to connect to a beagle bone black running Ubuntu?   I have tried smart hubs and dumb ones, (externally powered, with the power (red) cut from the BBB host to the Hub.  Sometimes it sees the hub and the device but mostly in sees nothing  when I do lsusb.  I can connect single devices OK.

 

One out of three times I can get it to work by powering up the board with the USB hub connected.  (Reset never seems to work. Neither does trying to use a udev reset.)

Another clue -  dmesg reports a 'failure to enumerate" USB error when it fails.

 

 

If someone has figured out how to do this, I'd appreciate knowing how you did it.

 

Thanks.

 

 

On the software side I have both a UVC camera working with the hydro RBX1 code, and the ROS Arduino Bridge. No joy with the openni Kinect yet.  I might try the freenect stack, but it conflicts with Openni. 

 

Alan N. Federman, PhD
http://drbot.best.vwh.net
http://www.linkedin.com/in/alan1federman
(408)227-6106 Home
(408)826-1795 Mobile

[anfederman@comcast]

Can someone please explain how USB Hub (port expanders) work or don't work with Ubuntu?  I've tried both 'smart' and dumb powered hubs without success on both a BBB and a laptop without success.   The devices work fine when plugged directly into the computers.  On the dumb hub nothing is seen.  On the smart hub a UVC camera is never seen (the smart hub does show up in lsusb) I can see a FTDI device on an Arduino in lsusb.  However when I try to talk to it, It fails to connect.

 

Now I have heard there is a USB 3.0 vs 2.0 issue, but I don't understand this.   Getting a couple of USB ports would be very useful to many projects that use small ARM based CPUS to run robots, so I am hoping someone can explain to me what is going on.  Perhaps this is a kernel or driver issue?

 

The smart hub is a DUB-H7 from D-link. The dumb is a 4 port unpowered that I am feeding external power to. I've cut the red lead back to the computer so no power surge on the external ports can back propagate to the host.

 

[Chris Albertson]

On Wed, Jul 2, 2014 at 8:26 AM, anfederman@comcast
<anfed...@comcast.net> wrote:

> The smart hub is a DUB-H7 from D-link. The dumb is a 4 port unpowered that I
> am feeding external power to. I've cut the red lead back to the computer so
> no power surge on the external ports can back propagate to the host.

Cutting the power leads might not work. The host USB port always
tries to detect the amount of power used. A dead zero power draw
might indicate nothing is plugged in. The first thing a USB port
driver does is negotiate the amount of 5 volt it will allow the device
to use. The protocol is to allow a small amount and wait to see if it
asks for more.

A good test might be to plug your modified hub into a Windows PC or a
Mac and see if this OSes recognize it.


--

Chris Albertson
Redondo Beach, California