Duemilanove with Sabertooth.

I recently got a nice set of toys. Including Duemilanove328 and a four wheeler platform. It has four motors connected to a Sabertooth motor controller (V1.02) old one.

Anyways. I just wanted to know if there was a nice tutorial in using those together. I have managed to make the motors spin :slight_smile: But I can’t control them. They just start spinning.
Here is my setup:

I have supplied 8 AA batteries in series now. Around 10-11V since they are a little bit used.

What I want to know is what is the easiest way to control the forward/backward and steering? Should I use a digital pin and write PWM pulses, should I (can the Duemilanove) use analog signal from 0-5 volts or should I ( can the Duemilanove) use some sort of serial interface?

Any sugestions?