A sprung magnet in a coil of wire? Bob Ammerman RAm Systems (contract development of high performance, high function, low-level software) ----- Original Message ----- From: Reginald Neale To: Sent: Saturday, September 02, 2000 1:26 PM Subject: Re: [EE] Simple direction sensing > Brian asked: > > >As a simple project for my local radio club I've designed a PIC > >Magic Wand that flashes 7 LEDs leaving a trailing message in the > >air. The flashing (ie message) is triggered by motion sensored by a > >mercury switch. > > > >Works fine if you wave right to left but moving left to right the > >message is mirror imaged (of course). > > > >Any ideas on a simple (and cheap) method of detecting whether > >motion is left-right or right-left so I can invert the message as > >appropriate. 2 mecury switches mounted in some way so that the > >leading edge triggered first seems the obvious solution but how to > >actually implement this? > > > I have seen a commercial implementation of this that used a > piezo element for motion sensing. One part of the disc was > anchored to the circuit board. The center electrode had a > piece of circuit board fastened to it with a lump of solder > at one end. Presumably this acted as an inertial sensor; > generating positive volts for waving in one direction and > negative in the other. > > > Reg Neale > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > use mailto:listserv@mitvma.mit.edu?body=SET%20PICList%20DIGEST -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use mailto:listserv@mitvma.mit.edu?body=SET%20PICList%20DIGEST