pic/midi programming

[Lennart Sorensen]

On Fri, Oct 30, 2009 at 03:58:13PM -0400, Dave Cramer wrote:
> On Fri, Oct 30, 2009 at 3:50 PM, Mel Wilson <mwilson-4YeSL8/OYKRWk0Htik3J/w at public.gmane.org> wrote:
> 
> > Lennart Sorensen wrote:
> >
> >> On Thu, Oct 29, 2009 at 03:13:24PM -0400, Mel Wilson wrote:
> >>
> >
> >  If you lose MIDI and do the sound yourself, I'd think start with 3
> >>>  fixed-pitch square waves for the drones and a tuned wave for the  chanter,
> >>> followed by the rudiments of a low-pass filter.  It might fool a few people.
> >>>
> >>
> >> The fixed pitch being two at about an A (and octave below the keynote
> >> of the chanter)  and the other one being an octave below that.  A being
> >> about 480Hz in this case, not 440.
> >>
> >
> > Really!  Just short of a tone sharp.  I can change the numbers for that.  A
> > MIDI solution can do it too, by manipulating the Fine Tuning parameter for
> > its channel.
> >
> > The square waves so far are almost-but-not-quite-entirely-unlike pipes.
> >  They will only fool people who want to be fooled, but I haven't done much
> > about a high-cut filter yet.  I tried to enrich the sound by detuning the
> > two high drone sounds by 1/8 semitone each way, but got an ugly beat at
> > about 3/second.  Probably needs more subtlety, maybe an LFSR to shake up the
> > detuning in a less repetitious way.
> >
> > The thing needs an ATmega128.  The -48, -168 etc. don't have enough timer
> > output compares to do it nicely.
> >
> 
> Well pipers spend a whole lot of time doing exactly this, tuning their
> drones ;)

Of course for midi there is the fun that the scale on pipes is nothing
like the equal tempered that the midi notes expect.  You will have to
use a pitch bend on almost every note as well.

-- 
Len Sorensen
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