[hpsdr] Blackfin

[Philip Covington]

On 7/12/07, Chris Albertson <chrisalbertson90278 at yahoo.com> wrote:
> ***** High Performance Software Defined Radio Discussion List *****
<snip>
> The cost of these DSP processors is getting to be lower than the cost
> of
> building a high speed interface.  What does the current HPSDR's USB
> interface cost?  The Blackfin is $14.51.   You can still have the same
> amount of flexibility too.  Then the front end is turned on it conects
> to
> the PC type computer - maybe even an Apple Mac Mini and downloads
S> software into the local DSP.  Because the software lives on the PC's
> disk drive it's easy to change, no flashing of eeproms involved.
>
> Now that ucLinux is on the Blackfin, the blackfin looks acts and
> smells like a PC and does most everything a PC can do but only
> it's an inch square and costs $15.  So really the idea, if you buy my
> "Blackfin becomes PC" idea is to put the PC inside the RF front end
> thereby making the need for a high speed interface moot.   One
> then uses his desktop PC is if it were a dumb terminal to access
> SDR software running on the Blackfin "PC".
>
>
> Chris Albertson
>   Home:   310-376-1029  chrisalbertson90278 at yahoo.com
>   Office: 310-336-5189  Christopher.J.Albertson at aero.org
>   KG6OMK/AG

Unfortunately it does not cost only $15.  There is a lot of support
circuitry that must go around that chip and when you start adding all
the costs up you into the $150-$250 range (in parts cost alone) for a
board that has the necessary hardware on it to support SDR
applications.

Then there is the DSP performance issue.   Until I see a working stand
alone SDR system based on one of these $15 chips, I am suspicious that
you are not going to be happy until you are into a much higher
end/higher cost BGA DSP chip.

I still think that a mini-ITX (or nano or pico when they become
available with decent performance) is the way to go for a stand alone
radio.   Then just hook up an Ethernet cable to the mini-ITX DSP
processor and use any PC to display the GUI running locally there.  If
you separate the GUI (and run it on an external PC when you want it)
from the DSP processing (running on the mini-ITX board)  then I don't
think you will need a high end CPU to get the job done.  You won't
necessarily compete with a Blackfin or TI DSP based board in power
consumption, but I think you'll out pace the performance of those
chips unless you go to the really high end/high cost DSPs.

Of course, designing a DSP board based on one of these chips would be
interesting. :-)

73 Phil N8VB

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