Measurement Specialties (formerly AMP) makes a piezo polymer vibration
sensor (LDTM-028K) with an attached proof mass that functions as a cheap
accelerometer:

        http://www.measurementspecialties.com/vibration_dynamic_sensors.htm

These are $.86 at Digi-Key.  They put out several volts of reversing
polarity as you wave them back and forth.  This may be adapable as a sensor
for this application.  They are 1" long by .5" wide, and need some wiggle
room, so they are a bit larger than an SOIC or DIP.


>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
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>
Jim Vannes
Instrumentation Specialist
Information Processing Consultant
School of Education
University of Wisconsin - Madison

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