will give you an overview of the techniques you'll use working with LilyPad components and sewing
with conductive thread.
Triggers
Electrically, we'll be connecting each trigger to a momentary switch, with the opposite side of the
switch connected to ground. Because the switch is normally open, the trigger pin will be
disconnected from ground and will "float" to a "high" state (3.3V) because of a pull-up resistor on
the board.
When you activate a switch, the trigger will be connected to ground, which is "low" or 0V. The
software knows that when a trigger is low, it's time to play the proper audio file.
Note that the very low voltages the LilyPad MP3 Player uses are
completely safe
. You can touch
anything on the board without fear of damaging yourself or the board.
Switches
You can certainly use hardware switches if you wish. If you're doing a fabric project, you may want
to use a
soft switch
. A soft switch acts just like its hardware cousin, but it is made with conductive
thread or fabric. The conductive areas are normally separated, but when you press / brush against /
twist / fold the switch, the conductive surfaces touch each other and conduct electricity. There are
lots of ways to make soft switches, and because this field is so new there is lots of room for new
ideas. Invent someting amazing!
where SparkFun engineer Dia made a soft
switch that looks like a flower that you brush against to activate.
Because there are five triggers, you can have up to five soft switches. You'll run each trigger to one
side of a switch. The other side of each soft switch will be connected to ground. You can run one
ground line to all the switches.
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