From: Jack Peel <jhp_at_cypress.com>
Date: Thu, 19 Sep 2002 14:29:36 -0700

Ahh.. after a little research I found out where the 20 came from in my
mind :) it's 20 log(x/y) for a ratio in dB (volts that is) :) But it's
still base 10
I believe it is still a log base 10 function. Hmm.. do we have any
friends
at archos that could tell us how to calculate this (they must have
already
done it :) Maybe not...

Jack


Philipp Pertermann wrote:

> From: "Jeff Waltzer"
>
> >
> > One could do a primitive approximation of a Log base 2
> function by
> > rotating the bits to find the left most location set bit.
> This would be
> > good if all you need is a number from 0 to 15.
>
> I believe I already found the perfect link. I just hate math
> and have been to lazy to understand that yet.
> http://www.dattalo.com/technical/theory/logs.html
>
> Phil
Received on 2002-09-19