Russell McMahon wrote: > He qualified his comment with the cavea "perpendicular to the earth's > surface", which is liable to be the useful direction for a single axis > accelerometer to be aligned when attempting to measure braking. But apparent accelleration due to gravity *is* perpendicular to the earth's surface on average. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist