Transcript Line Following With One Light Sensor EducateNXT Attach a light sensor To attach a light sensor to the EduBot, refer to pages 32-33 of.

Line Following
With One Light Sensor
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Attach a light sensor
To attach a light sensor to the EduBot, refer to
pages 32-33 of the NXT Building Guide (that
comes with the Education Kit).
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Reading the value of your light sensor
Click
Select
twice to
Then keep clicking
until
Now select the
port the light
sensor is in,
probably Port 3.
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Light readings for lots of things
Try getting light sensor readings for the following:
Midair ____________
Colored surface (Color ________ ) ____________
Colored surface (Color ________ ) ____________
Colored surface (Color ________ ) ____________
Darkest reading ____________
Brightest reading ____________
Black line on line follow board ____________
White area on line follow board ____________
Note: The light sensor does not read color. It reads how
much light is reflected – which is different for different colors.
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Edge following or line following?
The easiest
way to follow a
line is to follow
the edge,
moving on and
off the black.
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When on white it
When on black it
needs to go to black. needs to go to white.
?
?
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. . . And back to
black again.
While doing this, it
edges up the line.
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Basic Line Follow
Stops
Switch
B
Forward
Left
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Basic Line Follow
The Switch block
and its configuration panel
The trigger point value
determines when the sensor is
seeing black or white.
It is the average between the
black % and white %.
(Black% + White%) ÷ 2
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Basic Line Follow
A partially completed line-follow program should look like this . . .
IMPORTANT
Set Move block
duration to
“Unlimited.”
Don’t download
yet…
What still needs
to be added
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Add a Loop block. (The EduBot needs to line follow
forever.)
Then drag the Switch into the Loop.
1
2
3
Then Download.
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Have some fun
following the line . . .
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And for the teacher . . .
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Finished Line (Edge) Follow Program
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