ever thoght about adding LASER sensor to EZB a low cost LASER is NEATO XV-11 LIDAR and they say specs are close to the HOKUYO that goes for $1175,ebay you can get a complete NEATO XV-11 vacuum working good for $200 or used one (not always a good idea) for less i also have 11 LIDAR SENSORS that are tested with GUI program by a board made by another person or can very easy make one all is needed is TTL-USB converter and simple timing circuit to keep the motor at 300 rpm there are windows 7 and window xp drivers ,plus API COMMANDS ion the wiki sitei can trade you one for EZB shipped i sell them at $150 shipped LIDAR (LASER) is one of the best sensors for navigation neato xv-11 hack