JRH writes-

I set out this weekend to get an Arduino board to control my Roomba. (The Roomba has a great – and generally open – interface, and iRobot deserves significant credit for encouraging creative repurposing/extensions of their producs.) I’ve got a few project ideas in mind, but for an initial step just wanted to verify that the Arduino could a) send control commands (”move forward”, “turn right”, etc.) from the Arduino, and b) read sensor data (”something is touching my left bumper”, “I’m about to fall down the stairs”). This post contains my notes, which hopefully will help others doing this sort through some of the issues in a bit less than that I spent.