A piezo electric disc, soldered to the PC board at one edge, with a 3mmx25mm machine screw soldered to and protruding from the far edge. I've seen that as a tilt sensor in cheap car alarms. Just don't expect it to survive a lot of 4-wheeling. -Bob -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist