CHAPTER 25 ■ LAUNCHING THE LINE-FOLLOWERI cut a hole in the center of the paper with an ordinary paper punch. The switch bushing goes through
the center of the paper so the paper is sandwiched between the switch’s locking washer and the inside of
the plastic container. If the paper had been mounted on the outside of the container, the paper would have
become torn and soiled over time.
■ Tip You can add decorations or a nameplate to your robot in the same manner as the line-following switch
label. Simply put the piece of paper on the inside of the container, sandwiched between the washers of the
standoffs that hold the circuit board.
Trial Run: Following a Straight Line
The first test track for the robot should be a straight line.
- On an indoor, flat, non-patterned, evenly lit, light-colored floor, place more than
4 meters length of 2.5 cm wide dark tape in a straight line.
A line-following robot couldn’t ask for better racing conditions. The course may seem rigged for
success, which is exactly the point.
It’s like the high jump. Competitors start with the bar at lower levels, which they rightfully expect that
they can clear. After you’re assured that the robot is fully operational, then start increasing the difficulty of
the course and conditions.
■ Note As appealing as a sidewalk may look in daytime, the bright sun overwhelms the sensors, resulting
in very small voltage differences to compare. Covering the container in thick, opaque tape helps. But, it is still a
tough challenge for a robot designed for indoor lighting. So, avoid outside courses.
Figure 25-3. A printed piece of paper inserted inside the container for labeling the line-following switch