At 01.35 2012.06.17, you wrote:
>what about a second accelerometer, high pass filter, invert the output=20
>and apply a proportion of it to the original accelerometer signal like=20
>active noise cancelling.  There's a Microchip ap note or reference=20
>design about active noise cancelling in a dsPIC
>
>or you might not need the second accelerometer, isolate the vibration=20
>frequency and apply the inverse...
>
>Sounds easy but I bet it's not.

Yes also because the MPU cannot really use much of its time in FFT filterin=
g
(the frequency won't be fixed, as it's linked to the RPM of the engine), an=
d
the frequency analysis I have made on the PC showed that it was a very comp=
lex
source of noise.

Considering that the sensor wasn't going to add much functionality (but it =
would
have been cool to have), I think I'll just give up for this battle.


>
>Trevor Hancock
>--=20
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>http://mailman.mit.edu/mailman/listinfo/piclist

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