[sdiy] AvrSynth update: Patchable?

[David Brown]

It's an interesting little synth.  It's impressive in it's simplicity 
but I have no idea what to really do with mine.  The filter is a bit 
'thin' for my liking.  However, it is sitting here in a case with 16 
switches and 8 potentiometers and is easily programmable.

I keep thinking of writing a sequencer for it.  MOSI, MISO, and SCK 
are not used giving three more digital outputs ... clock input, 
trigger output, and gate output.

I never finished the output stage since I run it off +5v only.  Seems 
like a nice little adjustable gain stage that can be calibrated and 
you easily have a 8 stage sequencer.

Seems like each potentiometer could have a switch for quantization 
and some switching scheme to enable 2X stages.

Another thought is some type of programmable divider.  I did a 
program for my PSIM that I really like.  I divide a clock by 
selectable divisors such as 3, 5, 7, & 9.  Then I sum these outputs 
together through attenuators and quantize the output.  It makes 
a  nice pseudo-random sequencer that I adjust in real time until I 
get a sequence I like.

Each potentiometer could be it's own divisor ... 2, 3, 4, 5, 6, 7, 8, 
& 9.  The tricky part is setting the gain appropriately if you only 
use a couple of divisors vs. lots of divisors.

Just some thoughts.


At 02:44 AM 8/27/2005, Tim Ressel wrote:
>Then it hit me: How about a patchable Avr Synth? I
>think it can be done. Swap in a mega644 for the
>mega16, buying a 20MHz clock. Not sure how much one
>can get done between samples, but it might be enough.
>The hardware I have now should be enough to get
>started.
>
>Questions? Comments? Concerns? Consternations?
>
>--TimR