A more complicated approach, but still inexpensive, is to hinge the handle from
the display.  Use a very strong spring so that swinging it in either direction
bends the hinge a very small amount.  You could then use cheap contacts, or even
a pot, to tell which way the device is being swung by the bend in the hinge.
Use a pot, and you can tell the acceleration.

One item it note, though, most of these methods tend to equalize, after the firt
swing or so you won't be able to tel direction by acceleration forces in either
direction.

-Adam

Brian Jones wrote:
>
> 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?
>
> Thanks
>
> Brian
> Brian E Jones
> Centre for Java Technology
> IBM HURSLEY
>
> --
> http://www.piclist.com hint: The PICList is archived three different
> ways.  See http://www.piclist.com/#archives for details.

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.