I am trying to work on the intelligent vehicle only in just the part of the rear-end collision avoidance. For local vision (of course, Thai student doesn't have enough to pay for the GPS, which cost something like $5,000), I was able to find the ultrasonic from underground market, which costs only US$50. With that operating already, I still do not know how to integrate the braking system. Is it possible without the robot arm stepping on the brake? Can anybody kindly suggest? kittipat_0541(at)yahoo.com