It's too bad people have seemed to miss this post because I think that's the only solution for a stand-alone device. On 8/31/05, mchipguru@charter.net wrote: > IOf you use a 3 axis device and do the math it will work. Think vectors. At rest the system will measure a 1 G down. When breaking a breaking acceleration will be added in as another vector so you should be able to remove the 1 G and get a resultant vector.Team 190 from WPI did that a few years ago on their First robot when we put in an inertial navigation system. > Larry -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist