ComputerVoltageSources

Hi Eric

Thanks for the info & analysis...very enlightening

--- In ComputerVoltageSources@yahoogroups.com, Eric Brombaugh
<ebrombaugh@...> wrote:
 
> I agree that implementing a digital tracking PLL in
> the AtomPro code would be significant hassle.
>

if the code is written with with sync implemented from the ground up
it's less onerous- not easy , mind youbut less of a pain in the @$$.
  But modding synch into existing code (especially if linear or curved
gestures are produced) is... well... let's just say , it's not well
suited for a volunteer effort or even a 'reasonably priced' effort...
;'> 
also...
 designing-in the sync scheme demands that the sync conventions be
carved reliably in GRANITE before one begins to frame out the code...
i once stepped into an industrial control design project wherein the
user wanted to be able to drive the system with un-specified ,
'future' , timing references. Suffice to say it never even got as far
as a prototype.

 
> Probably the easiest hardware solution would be to
> remove the clock resonator from the AtomPros and run
> all of them from a common clock oscillator. That would
> probably mean building up a separate clock source with
> multiple outputs.
> 
> Unfortunately, the H8/3664 that the AtomPro is based
> on doesn't have an on-chip PLL like many MCUs
> available today do. This means that the clock source
> has to be full rate, rather than a lower frequency
> reference.
> 

whoa! that's a barrier, at those speeds all kinds of physical factors
 bear hard on the design.  

> Probably a bit more hackery than most folks want to
> deal with.
> 


certaily out of my league.... This is really located in BasicMicro's
realm but i doubt our little niche would merit the expense and effort
for them.


Thanks again for your insight
i learned something.

-doc



> Eric
> 
> --- drmabuce <drmabuce@...> wrote:
> 
> > Hi All
> >   External sync at the 'macro-level' as described by
> > Maestro Chang
> > must be implemented at the application code level. i
> > ,for one, don't
> > relish the prospect of trying to code smooth (or as
> > smooth as a DAC
> > allows) portamento in 24ppq increments. Things get
> > zippery enough for
> > me at full-on processor speed. But i'm way more of
> > an app. guy than a
> > 'kernel' guy so i put the question to some of you
> > engine tweakers....
> >   Is the prospect of syncing the main clock of 
> > multiple BasicAtom's
> > to a common timing reference unfeasible?
> >   i grasp that the processor is using a resonator
> > for it's timing
> > components and that Xtal components would be more
> > accurate. Also these
> > are passive , on board components of course and i
> > know better than to
> > think that multiple processors can 'share' an Xtal
> > especially over a
> > physical distance so i suppose my questions is
> > whether there's an
> > 'active' circuit that could overcome physical
> > proximity (et al) issues
> > and serve as a common reference for multiple
> > BasicAtoms?
> > 
> > -doc 
> > 
> > 
> > 
> > 
> > 
> > 
> > --- In ComputerVoltageSources@yahoogroups.com, "Gary
> > Chang"
> > <gchang@> wrote:
> > >
> > > Regardless of the accuracy of the timing source or
> > the AtomPro (and
> > > its scientific accuracy), it is essential that an
> > external sync
> > > reference can be used to enable the PSIM to
> > reliably playback at the
> > > same exact tempo.  This could be something as
> > simple as an audio tone.
> > >  (I would generate a tone from a pluging in my
> > DAW, making it
> > > repeatable and reliable).  The issue is the
> > frequency of the pilot
> > > tone, whether it be something mundane and standard
> > like a 24 ppn midi
> > > click that tempo changes with frequency, or a
> > higher resolution
> > > constant clock that allows for different tempos to
> > be subdivided
> > from it.
> > > 
> > > A MIDI timecode-locked device is running off of
> > its internal clock,
> > > but is periodically checking its timecode position
> > to the timecode
> > > coming it is being fed from the master.  If the
> > device is reasonably
> > > accurate (within a milliscond or two in a minute),
> > this method can be
> > > employed.  A routine of error compensation is
> > employed to keep the
> > > slave close to the master.  Most computer based
> > sequencing apps run in
> > > this mode.
> > > 
> > > A MIDI click-locked device takes the 24 pulse per
> > note midi clock
> > > pulse stream and references all timing information
> > to that.
> > > 
> > > gary
> > >
> > 
> > 
> > 
> 
> 
> 
>  
>
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