Hello,
I am wondering about slide potentiometers..
So what should be the resistance of slide potentiometers?
what is "the best" value for arduino from these:
500k, 100k, 50k, 47k, 10k, 5k ?
and is there any difference using linear versus logarithmic potentiometers?
I would like to test something like this:
http://personal.ilimit.es/principio/pmwiki/pmwiki.php?n=Main.6-pack
10k is the first choice.
A linear pot will provide a value directly proportional to position of the slider, unless you know you need to do something else, go with that. Log pots are typically used for controlling non-linear functions such as audio levels.
When a pot is used as a voltage divider like in the 6 pack the actual value of the pot is really not important, i did something similar but with 16 pots on two 4051 analog multiplexr IC's and i used 10K pots. But 100K pots would have given the same results.
As I recall, the ATmega ADC circuit is optimised for impedances of 10k or less, It will work with the higher resistances but according the ATmega specs, the conversion will take longer because of increased charge time in the ADC sample and hold.
Aha ! i didn't know that, lucky i chose 10K pots for my project then, it found a super offer on slide pots and just bought them 
Ok then 10k or less is the answer.
thank you all. 