BBB custom USB 4 Port Hub Expansion (NEW DESIGN)

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1

I have been developing a 4 PORT USB Hub specifically designed for the “quirks” of the BBB.

It takes a regular BBB, extends it by only 16mm and increases the number of HISH SPEED (480mbps) USB host ports to 4.

It looks like this when attached:
http://imgur.com/kxBbbZR
http://imgur.com/pMsLCIL
http://imgur.com/gF6ZV62

And this is what it looks like stand alone:
http://imgur.com/8RVfd3F

It works great, and lines up with the mounting holes on the end of the board near the existing USB Host port. When screwed to those mounting holes it is as structurally rigid as if the PCB was just longer. It also has hardware which is NON STANDARD for a normal USB HUB but which has been added to the HUB to correct for deficiencies in the BBB Host Port Power design. Which means that the problems of hubs appearing and disappearing and just generally misbehaving with the BBB do not occur with this hub.

The reason for this post is to let people know this thing exists.

I am currently working on the logistics of producing a batch of these boards, part of the unknown is if there is anyone who would be interested in buying it, and if so how many people that is. Volume has a direct impact on my ability to produce these at any reasonable price. So please dont ask me how much i will sell it for, my aim is to sell it as cheaply as reasonably possible.

Prototypes of this board are currently being used by a few Replicape developers with no reported faults.

It can be run either SELF Powered, or BUS Powered from the BBB.

A special non USB Compliant but useful mode is BUS Powered, but reporting to the BBB as SELF Powered. This is very handy for the use case where there are multiple devices and the sum total of their reported power consumption exceeds 500ma, but in use only one device is active at a time, so the average draw is only 500ma. Obviously, this mode is only intended for experienced people who really understand what the implications are.

If you have any questions I am happy to expand, if this device is of interest to you please let me know so I can try and work out what sort of volume i should produce, or if i should produce it at all.

Strontium

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Looks good, but whats the BOM cost ?

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I would be very interested in this board. I have multiple BBB boards and my interest would be for more than
one. Please keep me/the list informed.
Thanks
Don

4

Looks very cool. I’d be interested. Is there a schematic available?

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For what it’s worth, he sent me one of the early pre-production units - I use it every day and it works with zero issues hooked up to my Replicape+BBB 3d printer. I use the on-board power setup (proper USB standard at 0.5A), and it works flawlessly with a USB wifi dongle and webcam connected. I’ve had no brownout or power issues with it, and I have been very pleased with it.

What’s the saying? “The best products just work and you don’t notice them because they’re never a problem”? That pretty much sums up my experience. It’s near perfect - my unit was mildly fussy about how I installed it because of the cape’s power pins etc possibly causing a short so I needed to tape and hot-glue some metallic surfaces to avoid magic smoke escaping, but that was a pre-production unit :slight_smile:

As far as I could tell from my last conversation with Steven, BOM cost is dependent on the size of the production run - unit price goes down the more you make…

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Yes and no. For now, No, but the intention is for this to be OS hw, so once I commit to the design I will be making the design files available under an appropriate license.

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Thanks, I am pleased with it so far. As for BOM cost... well I hand built the first 6 boards myself and at that qty BOM cost is prohibitive.

Also the board is small, I know there will be an expectation its cheap. The problem is that expectation is based on people being able to buy 4 port hubs retail for $5. Buy a million of my hub and I can probably build them for that too.

So BOM cost is an issue I'm working on. As is production cost. All of which are difficult to solve at low volumes. That said I wouldn't announce this board if I didn't have a plan to build it economically. So bear with me and after I work out all the details I hope to announce a shipped price that is acceptable to most.

A secondary consideration is being able to produce it at the same/similar price for the forseable future. Thats also an issue for me. Too many projects are single runs because they can not get enough volume for a 3rd or 4th batch. If my plan works out that shouldn't be a problem for this board.

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Just some context for this. The Replicape is an awesome 3D printer cape,
and I originally designed this Hub because I wanted more USB ports to use
on my 3d printer with the Replicape.
SEE: http://www.thing-printer.com/product/replicape/

However, like my board, the Replicape pushes the envelope and is a bit
longer than a regular cape, further, the part that is longer contains these
nice pluggable terminal blocks, which have large through hole pins to deal
with the current requirements of the Replicape. My Hub extends directly
under this area of the Replicape. Its a nice match in one way because its
about the same length, BUT the tops of the USB A connectors are metal, so
if the pins of the pluggable terminal blocks short out on the tops of the
USB A connectors, well i am sure you can imagine the possible results.
However, it isn't really a big issue, putting a small shim to elevate the
board, or a barrier between the two neatly solves the problem, which is
what Jon is talking about. For a standard size cape this would not be an
issue.

http://imgur.com/eVW48in Here you can see the USB hub and replicape
together, I solved the problem by trimming the pins and using hot melt as
an insinuative layer.

Further my USB Hub is elevated from the BBB, by design, it lets me mount to
the mounting holes, reduces the overall length AND still allows cables to
connect underneath the BBB to the HDMI port, and easy access to the sdcard.

Bonus Picture: http://imgur.com/hjDOrX6

The fat red wire in that picture is SELF powering the BBB USB 4 hub,
tapping directly from the 5V power input on the BBB. A single wire is all
it takes (no extra external power supply for the hub). The GND return is
through the USB port on the BBB. This lets the hub easily drive a full
500ma on each USB port provided the power supply of the BBB is sufficient
for the task. Doing this is not required, if 500ma is enough, then just
plug in the hub and go, but if you want more power, this is a very easy and
neat mod to achieve it.

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Actually, I suppose BOM is not so important to me, with the way that I'm
thinking. But where i was going with this is that the BBG's come with 4 USB
ports already, so for one off designs it might behoove a hobbyist to just
buy a BBG. However, for a production system that needs to meet more than a
few 10's of boards, I can see where this could ideal. But then the question
would be does one really need HDMI, and whatever else the beagleobne black
offers over the green ?

So I suppose the question should be: What does this offer that one can not
achieve by using a BBG ?

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Of course quantities available ( of the various BB types ) could be a very real deciding factor too.

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The BBG only has one USB port, as far as I can tell.

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https://beagleboard.org/green-wireless

4 ports

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Yeah I guess I was remembering the BBGW and thinking of the BBG.

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We’ll be happy to stock it as alternate to existing proven USB Hub solution:
https://specialcomp.com/beaglebone/#21300

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Well, as you yourself pointed out it means one can use the HDMI output of the BBB and wired Ethernet. This board was designed with the BBB in mind, I was aware of the other BB variants (including the Enhanced) when i designed it.

For example, in the case of the 3d printer use, the Black may be a better option than the Green. It is for me, because it does have a HDMI output and that lets me have a local display easily attached to the printer. For example : http://www.thing-printer.com/product/manga-screen/ and wired ethernet.

As far as USB implementation goes, I just checked the BBG USB Schematics and make the following observations.

The 4 port USB hub of the BBG all share the same USB power output, and are limited to 1.7A total (0.425 per port equal share). A short or power fault on any USB port will render the other USB ports of the BBG inoperable.

My hub has independent 500ma power control for each port (2A total) And, yes this costs more, but is more robust and is a more compliant solution. A fault on any one port is isolated from the other ports and can be reported upstream to the BBB.

It all depends on your use case, which is the main reason I made this announcement to determine if there was enough interest in this board to explore producing it in volume for wider accessibility then just for me and a couple of people I know.

From the replies I have read so far, I am guessing there probably is, and so I am now doing the work to plan a production run and squeeze the production cost as much as possible so that its economic to produce.

Steven

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It all depends on your use case, which is the main reason I made this announcement to determine if there was enough interest in this board to explore producing it in volume for wider accessibility then just for me and a couple of people I know.

From the replies I have read so far, I am guessing there probably is, and so I am now doing the work to plan a production run and squeeze the production cost as much as possible so that its economic to produce.

Not arguing, just helping you make your case as to why, and when your USB board would be needed.

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Hello Steve

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Hello Steve,

The board looks pretty cool. How can I purchase 5 of these boards? How long will it take? How much and where do I send the check?

Regards,
Steve Mansfield
stephen.k.mansfield@gmail.com