Knob box add on for my 128 arduinome

I would like to make a detachable knob box for my recently completed starfire 128. I figure 4-6 pots. I would also like to place some LEDS underneath the knobs themselves and have them pulse to the tempo in live. I understand the recent arduinome firmware has code for hooking up to the ADC spots on the board so I think Im set for the pots. My question is how to read the tempo from Live and have it control the PWM output to pulse the LEDs like this http://principialabs.com/arduino-pulse-width-modulation/
I assume this would require a small MAX app that updates the "int time=" value in arduinome firmware