MCU/DSP Combination

"Phil Martel" <p.martel@comcast.net> wrote in message news:<UcLCc.177199$Ly.42054@attbi_s01>...
> "Jaime Andres Aranguren Cardona" <jaime.aranguren@ieee.org> wrote in message
> news:14a86f87.0406241401.2aa44b4b@posting.google.com...
> > babs@eng.umd.edu (fulan) wrote in message
>  news:<e2bf6f14.0406230756.f020060@posting.google.com>...
> > > Thank you for the many replies.
> > >
> > > My specs dictate that I have a 14-16bit ADC converter, this can be
> > > internal to the processor or external.  The requirement is the ability
> > > to read at least 256 samples per second, ideally 512 samples per
> > > second. We would repeat the reading for approximately 8 seconds and
> > > perform some FFTs on the data.  The philips LPC2106 seems like a good
> > > option however it lacks an internal A/D.  Furthermore, are their A/D
> > > converters capable of acquiring that many points at that resolution
> > > that quickly?(internal or external).
> > >
> > > Moussa

This may sound silly bit I ask if you need a full FFT.  Do you want to
find the magnitudes of ALL frequencies in your range or just a few
frequencies of interest.  If it's the latter then you don't need FFT
just synchrronus demodulation and that's alot simpler.

I can point you int that direction if it would help.

George

Thanx for the reply George,

You are correct, the customer does not necessarily need a Full FFT, I
would be interested in finding out about synchronous demodulation.

Moussa.

P.S.: we will still give him the ability to perform a Full FFT,however
it should be interesting to finding out how that can be optmized.


george.martin@att.net (George) wrote in message news:<e9d879fa.0406250554.27d9bd17@posting.google.com>...
> "Phil Martel" <p.martel@comcast.net> wrote in message news:<UcLCc.177199$Ly.42054@attbi_s01>...
> > "Jaime Andres Aranguren Cardona" <jaime.aranguren@ieee.org> wrote in message
> > news:14a86f87.0406241401.2aa44b4b@posting.google.com...
> > > babs@eng.umd.edu (fulan) wrote in message
>  news:<e2bf6f14.0406230756.f020060@posting.google.com>...
> > > > Thank you for the many replies.
> > > >
> > > > My specs dictate that I have a 14-16bit ADC converter, this can be
> > > > internal to the processor or external.  The requirement is the ability
> > > > to read at least 256 samples per second, ideally 512 samples per
> > > > second. We would repeat the reading for approximately 8 seconds and
> > > > perform some FFTs on the data.  The philips LPC2106 seems like a good
> > > > option however it lacks an internal A/D.  Furthermore, are their A/D
> > > > converters capable of acquiring that many points at that resolution
> > > > that quickly?(internal or external).
> > > >
> > > > Moussa
> 
> This may sound silly bit I ask if you need a full FFT.  Do you want to
> find the magnitudes of ALL frequencies in your range or just a few
> frequencies of interest.  If it's the latter then you don't need FFT
> just synchrronus demodulation and that's alot simpler.
> 
> I can point you int that direction if it would help.
> 
> George