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Testing And Calibration
Load and run the program called LF_TEST.BS2 (see Listing 1, starting on page 8). The purpose of this
program is to read and display what the Line Follower module "sees" in a DEBUG window. Using this
program we can test and calibrate the Line Follower module.
On screen will be a small representation of the BOE-Bot with the detector activity displayed in real time.
A "1" indicates the presence of the line under the corresponding detector. Of course, you'll need a test
track for the program (see to page 14 for instructions).
Or you can print this page and use the test strip below:
You should be able to move the BOE-Bot back and forth across this line and see the corresponding
detector bit change on the DEBUG screen. Be careful not to lift the BOE-Bot off the paper. The
emitter/detector pairs are focused devices and the mounting of the Line Follower module to the BOE-Bot
places them at the correct height above the surface for optimal reflectivity.
If output does not change, follow these steps to calibrate the Line Follower module:
1. Using a small screwdriver, turn the threshold pot completely counter-clockwise.
2. Carefully center the middle detector over a solid black line on white paper.
(the DEBUG screen should read: "11111")
3. Turn the threshold pot clockwise just past the point where the middle sensor detects the line
(the DEBUG screen should read: "00100")
Repeat the test and recalibration as necessary until all sensors accurately detect the line with no false
positives (detection when no line is present).
Parallax, Inc. • Parallax Line Follower (#29115) • 12/2001
Page 5
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