>Sorry, you said 60,000 rpm = 1kHz. Even better. Allegro >make quite a few for counting rotating gear teeth I don't think he did, he said the speed range of interest was 1000 RPM to 60,000 RPM. However a sensor designed to count gear teeth may well be better than the inductive sensor I suggested. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body