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FM Demodulation to extract Doppler Shift

Started by Chris87 October 22, 2010

Tim Wescott wrote:

> On 10/22/2010 10:40 AM, Vladimir Vassilevsky wrote: > >> >> >> Tim Wescott wrote: >> >>> On 10/22/2010 09:38 AM, Vladimir Vassilevsky wrote: >> >> >>> > FM at 4.8kHz ? A 8 bit microcontroller would do. >> >> >>> Good point -- I should have _thought_ about what the frequency >>> implied. And if an 8-bit micro will do, then one can easily do this >>> with floating point in a DSP. >> >> >> No. A 8-bit microcontroller would do in the floating point. > > > I didn't say it wouldn't, although it'd have to be a new one: > shoe-horning it into the 0.5MIPS machines that were available when I > graduated would be a challenge.
When you graduated, you accomplished what you needed with that 0.5 MIPS 6811 thing that you had. Nobody thought it could be possible. Nowadays a moron with dual core Pentium don't have enough brains to do some basic processing at 4.8kHz.
> Trying to do the job using the FFT, as the OP proposed, may bring it out > of the 8-bit class and firmly into DSP territory, however.
That could be 8-bit deal also as it doesn't have to chase the real time.
> The OP's post has "senior project" written all over it, in which case > one of his customer (i.e. advisor) requirements could well be "use this > here eval board".
There is a paradox which I can't understand: despite of the miracles of Google and Wikipedia, and public libraries with so many good books, why there are so many clueless folks around? VLV
On 10/22/2010 08:12 PM, Vladimir Vassilevsky wrote:
> > > Tim Wescott wrote: > >> On 10/22/2010 10:40 AM, Vladimir Vassilevsky wrote: >> >>> >>> >>> Tim Wescott wrote: >>> >>>> On 10/22/2010 09:38 AM, Vladimir Vassilevsky wrote: >>> >>> >>>> > FM at 4.8kHz ? A 8 bit microcontroller would do. >>> >>> >>>> Good point -- I should have _thought_ about what the frequency >>>> implied. And if an 8-bit micro will do, then one can easily do this >>>> with floating point in a DSP. >>> >>> >>> No. A 8-bit microcontroller would do in the floating point. >> >> >> I didn't say it wouldn't, although it'd have to be a new one: >> shoe-horning it into the 0.5MIPS machines that were available when I >> graduated would be a challenge. > > When you graduated, you accomplished what you needed with that 0.5 MIPS > 6811 thing that you had. Nobody thought it could be possible. > Nowadays a moron with dual core Pentium don't have enough brains to do > some basic processing at 4.8kHz. > >> Trying to do the job using the FFT, as the OP proposed, may bring it >> out of the 8-bit class and firmly into DSP territory, however. > > That could be 8-bit deal also as it doesn't have to chase the real time. > >> The OP's post has "senior project" written all over it, in which case >> one of his customer (i.e. advisor) requirements could well be "use >> this here eval board". > > There is a paradox which I can't understand: despite of the miracles of > Google and Wikipedia, and public libraries with so many good books, why > there are so many clueless folks around?
I remember being markedly clueless when I was young, and often when I venture into areas that I've never been, or haven't been for a while, I find that I'm still clueless (or at least suffering from hypoclueness). You're only 100% competent if you're not pushing yourself. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" was written for you. See details at http://www.wescottdesign.com/actfes/actfes.html
Tim Wescott <tim@seemywebsite.com> writes:
> [...] > You're only 100% competent if you're not pushing yourself.
On that we can agree on! Confidence is a sign of lingering too long in your comfort zone. -- Randy Yates % "Rollin' and riding and slippin' and Digital Signal Labs % sliding, it's magic." mailto://yates@ieee.org % http://www.digitalsignallabs.com % 'Living' Thing', *A New World Record*, ELO

Randy Yates wrote:

> Tim Wescott <tim@seemywebsite.com> writes: > >>[...] >>You're only 100% competent if you're not pushing yourself. > > > On that we can agree on! Confidence is a sign of lingering too > long in your comfort zone.
//-------- "A man goes to knowledge as he goes to war: wide-awake, with fear, with respect, and with absolute assurance. Going to knowledge or going to war in any other manner is a mistake, and whoever makes it might never live to regret it." Carlos Castaneda //-------- VLV
On Fri, 22 Oct 2010 22:12:13 -0500, Vladimir Vassilevsky
<nospam@nowhere.com> wrote:

      [Snipped by Lyons]
> >There is a paradox which I can't understand: despite of the miracles of >Google and Wikipedia, and public libraries with so many good books, why >there are so many clueless folks around? > >VLV
Hi Vladimir, IF DSP were easy, they'd call it a sport. See Ya', [-Rick-]