software EGs / PICs

Jay Vaughan jay at
Thu Jun 19 20:34:37 CEST 1997

>What got me thinking was a discussion about envelope generation.  This 
>is an application where a PIC would be perfect.  Choose one with the 
>8-bit A/D / D/A onboard, use a chunk of memory ( external EEROM ) for
>shape tables and you can have as complex and as fast a risetime as you 
>wish.  The Analog / DIgital section can output several channels of 
>envelope - laging, modulated, different waveshapes, etc...  You can 
>also use the Analog inputs for reading the panel pots - there is also 
>a serial input so communication ( updates ) is possible.

Very cool idea.  I'm not that sure I understand how the PIC would shape the
analog waveform, but I get the basic concept of it... and I like the idea
of having EEROM memory to store waveforms...

(I'm still learning a lot about DIY synthesis.)

I've thought of adding a motorized control section to my PAIA FatMan so I
can automate my pots -- and the heart of the system would be a Parallax
BasicStamp -- just something that I can hack around with, make the pots
move, etc. by way of serial commands sent by my PC (2400 baud) to the

I've started looking for automated pots -- if anyone has any suggestions,
let's here 'em!

And yes, it's a bit of an overkill project, but the FatMan is begging for
automation, it's easy to work with, and I'm sure I could use the same
automated pot system for other projects...

>The thread was initially talking about synth's ( Oberheim Xpandor, 
>etc. ) where one CPU was controlling all aspects of operation.  I 
>sugested that since these chips are cheap enough and require 
>essentially zero support circuitry, they would be an excellent 
>candidate for an embedded system of this type.

Fully agree with you on this one!



Jay Vaughan          
jay at       

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