Denny, I never believed someone will want to linearize a log pot...but it seems you're not alone: http://www.avrfreaks.net/forum/linearizing-logarithmic-potentiometer Log pot was invented to compensate the nonlinearity of human ear at low volume. I think the best answer is to buy a linear pot, but this will be too trivial solution. :) On Sat, Nov 28, 2015 at 6:38 PM, Denny Esterline wrote: > So the "Avoiding A/D noise toggling output pwm" thread has me thinking > about a recent "hack" project. > > It was a complete junkbox adventure and I used two pots that I didn't > realize at the time were LOG taper. It's by no means critical, but the > feeling is the old 80/20 rule - 80% of the useful range is in 20% of the > pot travel. So I'm thinking through how to linearize their values. > Yes, the simple answer is: > A/D -> math -> value > But I'm thinking creatively this week :-) > > I know you can add fixed resistors across a linear pot and get a LOG > approximation, but I've not explored the reverse..? > > If I'm forced to do it mathematically, does anybody have an efficient > algorithm? > > I'm thinking the cleanest way may just be a lookup table crafted in Excel= .. > A full 10 bit (1024 value) lookup table is probably overkill, but it has > the virtue of simplicity. > > -Denny > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .