PROJECTS: RFID TEDDY BEAR
LOVES TO PLAY!
Connecting Sounds with Objects
Combining object sensing with sound is more
powerful than you might think. The most obvious application is just for the bear to make
appropriate noises in response to other toys.
But what about interacting with other objects,
besides toys? An ID tag stuck inside the cover
of a book can trigger the bear to read it. A tag
in a CD case can trigger the bear to play the
corresponding music, without a small child’s
having to fuss with smudge- and scratch-prone CDs or age-inappropriate computers.
If you have a child who just won’t listen to
you, maybe they’ll listen to their friend the
bear. Record some tags in “bear voice” saying
that it’s time to go to sleep or time to brush
our teeth. And don’t forget to give the parents
a keychain RFID tag that has no sound associated with it. This very handy tag will instantly
make the bear go silent! These are some of
the Charlie’s Bear sound applications I’ve
used successfully with the kids in my life, and
I’m sure you can come up with many more.
Alternatively, you might like to add some
kind of motion-sensitive switch and modify
the code so it uses less power when idle. With
software power management, turning off the
RFID antenna will save the most power. Then
the batteries will last long enough that you
might never need to switch your bear off.
Or maybe the bear would like to dance
along with the sounds it makes? Consider
adding a vibration motor or stepper motors
that the Arduino can trigger along with the
sound files. Perhaps you can modify the code
so that some tags play sound and others
cause vibration or movement.
Let us know how you use Charlie’s Bear! ;
Mod Charlie’s Bear!
The software for Charlie’s bear is fairly
straightforward and easy to modify. For
example, the existing code interrupts the
current sound playing when a new tag is
brought into range, but you can change its
behavior so that it plays the current sound
file until the end before starting the new one.
There are a few obvious physical modifications you might like to try. The bear has
no power switch, so to turn it off you need to
unplug the battery pack. Instead, you could
add a switch inside a paw or combination
» Charlie’s Bear software — CharlieBear.pde
» RFID tag identifier — RFIDread.pde
» Arduino IDE — arduino.cc
» Audacity — audacity.sourceforge.net
114 Make: makezine.com/28