A receiver circuit is housed
in one plastic pumpkin, and
another pumpkin houses the
transmitter (see Chapter 9).
When somebody walks
between the two, a beam of
infrared light is disrupted
and a recorded message
plays using a sound chip.The Couch Petato circuit from Chapter 14 uses a vibration sensor
to detect your pet when it jumps on a piece of furniture, and a
sound chip to tell your cat to scat.009683 ci_f.qxd 6/1/06 3:58 PM Page 8