[hpsdr] What can we do with 2 cards [long]

[Lyle Johnson]

> I'm sorry, but I'm still back on the why not put the connectors on the JANUS
> 
> (a) DB-25 to mimic the Parallel port
> (b) use some higher density connectors for all the audio. Design a fanout cable like the D-44!

There are lots of potential solutions that will work.

Personally, I'd rather keep Janus focused on audio interface and let Ozy 
handle the digital interface, use standard cables and call it a day :-)

Then get on with other things!

And I really don't like the bulky adapter required by the Delta 44.  Of 
course, others really don't like the 3.5mm connectors.

> Then there is space on the OZY for the fiber connection back to the host computer to support higher data rates.
> Keep the USB-2 for control of the HPSDR, but use the fiber to ship the audio back and forth.

What is the protocol that the fiber would be implementing?  If it is 
audio stuff, like SP/DIF or AES3, then doesn't it logically belong on 
Janus where the ADC and DAC reside? If so, that puts the digital/control 
I/O right back on Ozy and the USB port.

But, we can easily stream reasonable bandwidths between Janus and Ozy, 
and Ozy via USB to a PC.  On a single USB port.  Works with non-optical PCs.

> I thought everyone was complaining about USB having bandwidth limits. USRP is complaining about that problem.

USRP was designed to do HDTV.  For that, they need lots of bandwidth. 
In the end, no matter how much bandwidth you have, it will not be enough 
because you will come up with an application that needs more.  Even if 
it doesn't need more, we will convince ourselves that it does.

I'm for trying to see what we can do in the bandwidth we have on our 
lowly USB port managed by an 8051 in the guise of an FX2.

***

In a previous life, I designed systems that would control large, open 
pit mines in real time.  The first system worked extremely well and used 
a 600 baud radio link to interface with the equipment operators, provide 
direction and gather status.  1978-1980.  We then went to 1200 bps and 
handled the largest mines on the planet, in real time. 1980s.

Then we wanted graphics displays and touch screens and convinced our 
customers that they wanted them, too.  And then color, and then...  We 
went to 9600 bps (1990s), then to distributed multi-megabit links 
(2000s).  The GUIs were fun -- and a source of continual frustration -- 
but the productivity of the mine never was significantly improved more 
than the old, 1200 bps stuff could deliver.

***

I find it interesting that there is already a USRP (Universal Software 
Radio Peripheral) and we're busy designing yet another Universal widget, 
complete with another Universal backplane and Universal cards that plug 
into it to provide generalized solutions :-)

Feel the Force, Luke...

73,

Lyle KK7P


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