How do those oscillations occur, is the thing I'm curious about at this
point?  Instead of trying to stifle the effects, sometimes it's far
easier to solve the problem by solving it's cause.

You do have decoupling caps (say 10uF and 0.1uF in parallel) on the
Vss/Vdd at both the ISD2560 and the SX, right?  And perhaps a small
series resistor inline with the SX's Vdd, to reduce coupling of digital
noise to the ISD?  One-point grounding between the two, as well?

  Mark

Bill Pierce wrote:
> I'm working on a project that uses an ISD2560 sound recorder with an SX as
> the controller. The circuit is working but there is background noise
> generated by oscillations that occur when I read 2 pots that control the
> frequency of the playback. If I add delays between the code that reads the
> pot I get a lower pitch but I can't get it to go away completely without
> making the response time to slow. I tried putting filter caps of different
> sizes but no success. Any suggestions would be great, I'm a software guy and
> this hardware stuff kills me sometimes.
>
> Thanks
>
> Bill
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