Octave synthesis on a PIC microcontroller

Dave Halliday dave.halliday at greymatter.com
Sun Jun 22 09:29:36 CEST 1997

>>congratulations..... but what i would really like to see is a PIC based
>>exponential convertor so we can just make linear osccillators and voltage to
>>current convertors
>>and forget ovens & matched transistors.... just the one exponential
>>convertor with a couple of hex sample& hold chips & thats the nastiest
>>partof a synth gone.....
>     Yes! I've been pondering this solution for over a year now (haven't 
>     had the time to do more, alas). Seems like such an obvious way to 
>     tackle the problem, I've been trying to figure out what the downsides 
>     that I haven't thought of could be.

Problem there is that many of the PIC chips use slow A/D/A - they use 
a cheaper integration method of conversion than the more expensive 
sucessive approximation or the really $$$ flash conversion.

Don't know if you could get the accuracy plus enpough speed for 
several channels...

You *could* just use one oven and matched transistor with the sample 
and holds - I am just wondering what the parts count would be...
--- Via Silver Xpress V4.4 [Reg]

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