USB OTG cable

Hi,

After some struggle (a summary here - http://openology.blogspot.com/2009/01/usb-otg-brief.html), I had modified a USB-A male to USB-miniB male cable - connected ID pin to GND - to make it a USB-A male to USB-miniA cable. Now, when connected, Beagle becomes does become a host.

I used this cable to connect to a hub, to which I connected my peripherals - keyboard, mouse and USB ethernet adapter.

Which ever distro I booted (Angstrom/ Debian/ Ubuntu), I had the same problem with my ethernet adapter - the connection always got dropped and dhcp ran into problems very often than not. One thing I had noticed that this ethernet adapter was always recognized as a low speed USB device.

I had recently come across another USB cable - which I was told was a high speed USB cable - the difference between the cable I had modded earlier and this high speed one was - one - high speed cable had a shield and - two - the caps of the connectors were connected via a fifth wire. Guess that’s what makes the cable high speed capable.

I have modified this cable to connect the ID pin to GND on the mini USB connector. I am now hoping that my devices (especially USB ethernet adapter) will all be recognized as high speed devices, and I wouldn’t run into the problems I have been seeing earlier.

Can someone please help confirm that this cable is OK to be used with Beagle - especially that the caps of the connectors were both connected through a fifth wire? Would this config be OK with Beagle? Or will I run into problems if I use this cable?

I wanted to confirm from experts in the group before I actually connect this cable. Please help!

I used this cable to connect to a hub, to which I connected my peripherals
- keyboard, mouse and USB ethernet adapter.

Which ever distro I booted (Angstrom/ Debian/ Ubuntu), I had the same problem
with my ethernet adapter - the connection always got dropped and dhcp ran into
problems very often than not. One thing I had noticed that this ethernet adapter
was always recognized as a low speed USB device.

I had recently come across another USB cable - which I was told was a high speed
USB cable - the difference between the cable I had modded earlier and this high
speed one was - one - high speed cable had a shield and - two - the caps of the
connectors were connected via a fifth wire. Guess that's what makes the cable
high speed capable.

In case you have connected the BeagleBoard to a High-speed HUB all communication between this and the Beagle will be high-speed. The HUB will in case needed do the speed translation from high-speed to low/full speed for connected devices.

In case your Ethernet device shows up as a full speed device I see three different possibilities:
1) Either the Ethernet device is actually a full-speed device – Believe it or not, but the cheaper ones only supports USB full speed although they support 100Mbit/s Ethernet.

2) The HUB you are using is only full-speed capable. You won’t be able to see this on the mouse and keypad (since they are normally only low- and full-speed compatible anyway). If the hub is only full speed capable the Ethernet device will fall back to full speed mode as well

3) You cable isn’t high-speed capable (I assume it isn’t, since it isn’t shielded and have the wrong colors) thereby corrupting high-speed data transfers all from the beginning. The protocol will then fallback and try to enumerate the HUB as a full speed device, which succeeds – From here the same description as in 2).

AFAIR a high-speed cable is required to be shielded. Secondly it has a requirement on the cable wire colors. Data wires need to be white and green. According to the picture at http://openology.blogspot.com/2009/01/usb-otg-brief.html your cable is not following this convention – and thereby at least can't be USB 2.0 certified…

In your case I would go ahead double check that your devices (HUB and Ethernet dongle) are actually high speed capable (i.e. connection them to a PC asn testing). In this case I would give the other cable a try…

Best regards - Good luck
  Søren

Soren,

Thanks for the reply!

I had modified another cable - a high speed one - it has shielding and the correct colors and don’t see the problems that I saw on the network adapter any more.

The network now works like a charm and so do the other peripherals.

Needless to say, will update my blog post with my learnings and images of the new cable.

Thanks again for all the patience and replies!