USB on DSP

hi,
i am totally new to DSP programming. i have done simple image processing
using labview and a webcamera. i would like to know if is it possible to
dump the code on to a blackfin processor and make it work. (i mean the
computer has all drivers for usb communication and also webcam drivers.
how can i specify a usb communication using DSP). 
please help on this matter..

vishal patel

vkp_patel wrote:

> hi,
> i am totally new to DSP programming. i have done simple image processing
> using labview and a webcamera. i would like to know if is it possible to
> dump the code on to a blackfin processor and make it work. (i mean the
> computer has all drivers for usb communication and also webcam drivers.
> how can i specify a usb communication using DSP). 
> please help on this matter..
> 
> vishal patel
> 
> 
You could theoretically have the DSP manage the USB communication with 
the webcam.  The problem is that your DSP would have to be a USB master, 
and would have to drive the webcam.  Since the machine codes are 
completely incompatible you'd have to come up with these drivers yourself.

I would consider alternatives before I jumped on this:

1.  Use a single-board computer with USB for communications.
   1a.  Using the SBC for DSP, also
   1b.  Using a separate DSP chip.
2.  Use firewire.  There are good firewire webcams out there (at
     least there _were_), and while a firewire node is much harder
     to program than a  USB slave, it should be much easier to
     program than a USB master plus driver.

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google?  See http://cfaj.freeshell.org/google/

"Applied Control Theory for Embedded Systems" came out in April.
See details at http://www.wescottdesign.com/actfes/actfes.html

"vkp_patel" <vkp_patel@yahoo.com> wrote in message 
news:FOKdnR_mEZP_l5vYnZ2dnUVZ_qudnZ2d@giganews.com...
> hi,
> i am totally new to DSP programming. i have done simple image processing
> using labview and a webcamera. i would like to know if is it possible to
> dump the code on to a blackfin processor and make it work. (i mean the
> computer has all drivers for usb communication and also webcam drivers.
> how can i specify a usb communication using DSP).
> please help on this matter..

That is a huge question. If you want to do isochronous streaming video you 
need to have a very good background in USB and the streaming mode that it 
provides unless you happen to be lucky enough to find a convenient reference 
design. There are no good texts I've found on this subject. The basic texts 
for USB are http://www.usb.org/developers/docs/usb_20_05122006.zip, and the 
much more readable http://www.lvr.com/usbc.htm that sadly almost completely 
ignores streaming USB.

If all you want to achieve is a bit bang between PC and embedded device, 
consider some of the many off the shelf devices like 
http://www.ftdichip.com/Products/FT245BM.htm

Believe me, writing your own firmware and host OS drivers to support your 
isochronous USB streaming device is an extremely time consuming and complex 
job.

Regards, Howard 

Tim Wescott wrote:

> vkp_patel wrote:
> 
>> hi,
>> i am totally new to DSP programming. i have done simple image processing
>> using labview and a webcamera. i would like to know if is it possible to
>> dump the code on to a blackfin processor and make it work. (i mean the
>> computer has all drivers for usb communication and also webcam drivers.
>> how can i specify a usb communication using DSP). please help on this 
>> matter..
>>
>> vishal patel
>>
>>
> You could theoretically have the DSP manage the USB communication with 
> the webcam.  The problem is that your DSP would have to be a USB master, 
> and would have to drive the webcam.  Since the machine codes are 
> completely incompatible you'd have to come up with these drivers yourself.
> 
> I would consider alternatives before I jumped on this:
> 
> 1.  Use a single-board computer with USB for communications.
>   1a.  Using the SBC for DSP, also
>   1b.  Using a separate DSP chip.
> 2.  Use firewire.  There are good firewire webcams out there (at
>     least there _were_), and while a firewire node is much harder
>     to program than a  USB slave, it should be much easier to
>     program than a USB master plus driver.
> 
I forgot to mention -- of course you'd have to do a bunch of hardware 
work, too.

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google?  See http://cfaj.freeshell.org/google/

"Applied Control Theory for Embedded Systems" came out in April.
See details at http://www.wescottdesign.com/actfes/actfes.html