Parallax, Inc. • Parallax Line Follower (#29115) • 12/2001
Page 18
Making Tracks
This simplest way to construct a track for your Line Follower is with white art paper and a black, ¼”
(6 mm) wide felt tip marking pen. Select a heavy paper stock, one that is opaque, has a matte (non-
glossy) finish and is designed to take paint or pens (papers intended for watercolors work well). Draw
the line carefully, making sure that it is no wider than one IR sensor. If you prefer a white line on black
paper, you can use ¼” (6 mm) model striping tape to make the line.
For very large tracks, some robotics clubs use 1” white athletic tape on black photographers backdrop
paper. It may be necessary to make cuts in the tape on the insides of sharp corners. Be sure to burnish
the tape down flush so that it doesn’t interfere with the sensor array. Figure 7 shows a small practice
track made with black foam core and 1” athletic tape.
Figure 7: Practice Track
Troubleshooting
You may find that some track and environment combinations cause trouble for the Line Follower module.
Tracks that use a black line on white field that are lit with fluorescent lights or are affected by sunlight
can be troublesome. If adjusting the threshold pot does not solve the problem, you can make a skirt
from a
5
/
8
” (16 mm) wide strip of black construction paper. Wrap the strip around the body of the
sensors and secure with cellophane tape.
Figure 8: Line Follower With Light Skirt
