>>Any reason for using 16 bit shift register if you are
>>riding PICs?
>>
>>Mike.
>>
>
>So I can alter the waveform manually, via trimpots, without having to
>reprogram.
>
>For example, to conserve power I can reduce the duty cycle but still have a
>rounded waveform. Not to mention experimenting with assymetrical waves.
>
>Someone mentioned using PWM instead of a shift register, but that would
>similarly limit this type of wave shaping.

I suspect that PWM could make it easier to do an arbitrary waveform. By
having a sine table in memory you can step through it at any rate you want,
and can also arrange scaling of the values as you go to get amplitude
variations. I have planned this sort of thing in the past by using ROM
tables, although that part of the project was canned before I got the coding
done. However by using such a table as a base, and then downloading
adjustment values into EEPROM on the fly you could make arbitrary
adjustments to the waveform quite nicely.

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