I thought this would be a great
problem to solve with a new
electronic project. I envisioned a
small box that could be moved
from table to table and would
automatically enforce the rules.
The build constraints would be
to construct it inexpensively and in a
timely manner. This basically meant
that it would need to be made from
parts that were on hand since
shipping things in from most places
takes a few weeks.
My first thought was to use a
motion sensor, but it would need to
be placed in such a way that it
wouldn’t send false alarms whenever
we were walking around the table.
Infrared beams were another idea,
but it would require IR LEDs and IR
July 2014 37
Cat Away schematic.