tr an smitter
circ�it
(s�a� in ste� ��
wo w�
wha t � ppen � ?
recei� r
circ�it
light mode
sound
mode
bright
led
use scr� dri� r to
adjust s� sor to
minimum sen siti vity
power
data communication
PROJECT 5:
Learn how to wirelessly transmit music using a digital signal.
mic
light
sensor
speaker
or
ir led
TimE:
30 mins
diFFiCulTy:
Plug audio cable into microphone
module and an mp3 player and
play your favorite song.
Now swap out the IR LED for the bright LED and
see what happens.
Put diff erent materials between the light source
and sensor. What happens?
Place both circuits on a flat surface, like below.
mp3
player
audio
cable
Make these two circuits.
9�
ma� s�re the
IR LED
is at a 90 de�ree an gle
to the
lig�t s� sor an d
adjust s� sor to
minimum sen siti vity
hold about
3� above light
sen sor
hold at least 12�
away fro
m light
sen sor
NASA uses electromagnetic
waves to communicate with
satellites orbiting Earth.
ma� sure
the
volume is
all �
way up�
1
2
3
4
5
How does it work?
Your digitized music is converted
into a series of light wave pulses.
The pulses are decoded by the light
sensor and converted into sound waves
by the speaker.
tr y bloc� ng the
light sen sor wi th
your ha nd or a
piece of paper!
turn
me on
yO
u
’l
l
N
EEd
18
NaSa
TODAY
