The sensor mentioned here was used in the Frontiers Robotics summer program at WPI. We chose it mostly because of the cost and the chance to illustrate some advanced programming issues like interrupts and timers.
Another ultrasonic sensor is available from DigiKey and does provide an easier interface - it outputs an analog value proportional to the distance measured:
http://dkc3.digikey.com/PDF/T042/1310.pdf
the 387-1000-ND.
It is true that using ultrasonics on a robot is subject to "interference" from other robots and objects that get in the way. We used ultrasonics in the team 190 robot to autonomously detect the stairs, then the upper platform where we were assured that there would be no obstacles or other robots interfering.
As was mentioned, you need to integrate the information from other sensors to provide a better picture of what's going on around the robot. We used wheel encoders for precise distance measurement and gyros for pitch and turn information in addition to the ultrasonic rangefinder.
Between all of these sensors we were able to successfully hang autonomously in most matches.
the golden rule of robotics for the 21st century: Do unto robots as you would have them do unto you - KenWittlief [more] 
05-08-2004, 13:45
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