iRobot Roomba Open Interface (OI) pinout The Roomba Open Interface (OI) is a software interface for controlling and manipulating Roomba?s behavior. The software interface lets you manipulate Roomba?s behavior and read its sensors through a series of commands, including mode commands, actuator commands, song commands, and sensor commands that you send to the Roomba?s serial port by way of a PC or microcontroller that is connected to the Mini-DIN connector.