pic/midi programming

[Mel Wilson]

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.

	Mel.
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