USB connector not Mini-AB?

Stroller stroller at stellar.eclipse.co.uk
Mon Jul 28 13:12:58 CEST 2008


On 28 Jul 2008, at 10:44, Andy Green wrote:
> ...
>> Will the next Freerunner revision have a proper mini USB-AB
>> receptacle like the one at
>> http://www.cypressindustries.com/mini_usb_ab_connector.html ?
>
>
> How do you think what is on Freerunner right now differs from that?
> Seems to be what we got already.

If you look at the Freerunner its USB port is kinda trapezoid. Kinda  
"equilateral trapezoid" (??) with a "kink" in the shorter sides.
http://en.wikipedia.org/wiki/Trapeziod

If you compare the two they are clearly different:
    http://www.cypressindustries.com/products/images/ 
ccmusbb-32005-201.gif
    http://www.cypressindustries.com/products/images/ 
ccmusbab-32005-700.gif

The Freerunner's USB port is that widely used on other devices as a  
USB mini "B" connector.

I have here immediately to hand a Canon dSLR camera, a Sony PSP  
gameboy and Sony console joypad that all feature similar sockets (and  
at least charge with the same cable that the Freerunner uses).

If you look at the cypressindustries link that Charles posted you'll  
see it's a different shape - the metal "rim" has 6 straight sides. It  
reminds me of a firewire (400?) connector, although its aspect ratio  
is quite opposite.

I think the point is that the other devices I mentioned are *only*  
USB "B". They are connected to computers only as peripherals. You  
will not connect a keyboard or a mouse to a camera or joypad.

The Freerunner, on the other hand, may be connected to a computer as  
a peripheral (it is USB "B" for firmware flashing or if the FR were  
to pretend to be a solid-state storage device) or may have  
peripherals connected to it (the FR must behave as USB "A" if a  
keyboard or mouse is connected).

As I read this it the Cypress mini USB-AB receptacle Charles links to  
is intended to distinguish that it is *not merely* a USB "B" device,  
but capable of USB "A" functions also. I conjecture such a USB "AB"  
connector might be "split" in order to perform both A and B functions  
simultaneously, or provide other features not available merely  
"abusing" a USB "B" socket.

Stroller.





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