generating a -10v...+10v control signal from an arduino

Using Arduino General Electronics
20

hi guys,

i am plugging numbers into this calculator... could you verify some of my assumption??

http://sim.okawa-denshi.jp/en/PWMtool.php

fPWM= 480 (this is the operating freq of the pwm timer? )

duty step -- the output i want. 50% if i wanted around 5v output, based on switching 0-10v

R and C values?? I got a 'pretty' curve at R =5k and C =10u. Could i expect to get better??

what is the fc - cut off frequecy term mean?

thanks
jon