can i just use pwm
No.
can i just use pwm with a low-pass filter?
No.
You need something like this:-
http://arduino.cc/en/Tutorial/SPIDigitalPot
can i just use pwm
No.
can i just use pwm with a low-pass filter?
No.
You need something like this:-
http://arduino.cc/en/Tutorial/SPIDigitalPot