Maxuino for PWM output//

Hello

Anyone using Maxuino,
Is there no need of Arduino coding besides just loading Firmata for controlling just Arduino PWM output from Max/msp?
I am about to just sending PWM voltage value to control analogue input on Velleman K8064 (DC control AC dimmer)
Do I need to scale it in Arduino or Max?

please help

I assembled Velleman K8064, and it seems working, but have no idea how to control from max.
also how do I connect a circuit between arduino and K8064?