Pffuh. That has been a long time since I've been able to proceed on my project. Anyway. Finally got the nerve to order myself some distance measuring sensors: two Sharp GP2D02 (digital IR distance measures) and two SRF04 Ultrasonic range finders. Pretty cool stuff. I have placed the GP2D02's on the left and right of the vehicle to detect proximity to walls. The sonars I put in front. So I got some software to write. For the GP2D02's I got some routines of the net, the sonars I liked to do myself. And: it works. I wrote this little assembly program to send a pulse and count the time till its return. Amazing, huh? Now I can build myself a true wanderer that doesn't run into walls. I'll put the stuff on my website for you to see and comment.