Re: DSP System


"Nico Coesel" <nico@xxxxxxxxxxx> wrote in message
news:46a1c026.1050243920@xxxxxxxxxxxxxxxxx
"David L. Jones" <altzone@xxxxxxxxx> wrote:

On Jul 20, 6:05 pm, "Jon Slaughter" <Jon_Slaugh...@xxxxxxxxxxx> wrote:
"David L. Jones" <altz...@xxxxxxxxx> wrote in
messagenews:1184912759.591055.253980@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx



On Jul 20, 1:55 pm, "Jon Slaughter" <Jon_Slaugh...@xxxxxxxxxxx> wrote:
How hard is it to actually implement a DSP system?

I've been looking at the TMS320C6720 and some conversion devices and
it
seems I can gather all the components needed but I really don't have
a
good
idea about how to go and implement something like that. The pdf's
I've
looked at on TI's don't really go into detail about how to actually
put
something together(atleast the one's I've seen).

All I want to do is take an analog signal, add some digital
filtering(well,
whatever I want once I get into the software side), and output the
signal.

The digital conversion's seems pretty straight forward and I was plan
on
using something like the PCM1741 and PCM1807 or something similar for
the
conversion(although I ultimately want to go to 192khz).

I think all I'll need is the converters, memory, and the dsp? (I
don't
think
I'll need a controller?) Is it going to be much harder than just
hooking
all
these up together and then downloading some code to the dsp?

At this point I do not need anything fancy and just want to apply
some
effects like reverb and chorus to a signal for a start. The biggest
problems
at this point is the IC packaging for these devices as most are out
of my
reach(BGA, for example) for prototyping.

Is such a conceptually simple project out of my ability as a
hobbyist? Do
I
need to come up with some prototyping schematic and get some pcb's
made
for
prototyping? I'm really not sure how to go about this and I can't
find
any
documents online that can give me some details about the process ;/

Any ideas?
Thanks,
Jon

What you need is a DSP development board. They will usually contain
all you need to get a project like this off the ground - the DSP chip,
any required memory, a few ADC inputs and DAC outputs etc, many are
targeted specifically for audio use. It's already done for you.
TI have a complete range of them:
http://focus.ti.com/dsp/docs/dspsupporttnp.tsp?sectionId=3&tabId=2079...

They aren't particularly cheap, but it can save you weeks of mucking
around with hardware, when really a project like this is all about the
software.

There is nothing really special about DSP's, they are essentially just
a microprocessor with specilised hardware making them faster at math
and signal processing functions than a regular microprocessor or
microcontroller.

I've looked at that but I can justify the expense. Its got, what, about
20-30$ worth of components and another 20-30$ for the pcb (if that) yet
they
want 400 for just a starter? If theres something I'm missing that makes
it
worth it then please let me know about it but it seems like its not
worth
it.

Jon

You are paying for the convenience, it's called "starter" for reason,
it gets you started with no with fuss and no wasted effort, productive
from day one.
You might be able to build it for less, but how much is your time
worth?
You have to design your board and get it made, and all the research
that goes along with that. Get the parts in one-off qty that aren't
always available as such. Then you have to sort out the software tools
and libraries etc etc

If you are going to build your own circuit you'll have to get your
hands dirty and go through all that anyhow. A starter kit is nice, but
the limits are usually reached quite soon (like having no room for
surface mounted components). I mostly design my own starter kits
(based on diagrams from existing starter kits) which only contain what
I really need to evaluate.


Have you done anything like this and if so how did you start? The thing I'm
worried about is all the trouble to set it up then miss something. As far as
I see it, its mainly just routing and there are few little things like the
power supply and power issues involved but because I can't seem to find
anything on how to do even a basic dsp I'm worried I'll easily miss a lot of
things ;/ The datasheets only seem to talk about very specific things but
really how to connect the different components. (I do understand most of its
routing but I guess I just need to see what someone else has done and what
works)

Thanks,
Jon


.

Loading