Here are some things to try if your Ozobot robot ignores the color coded instructions:
1. Make sure your lines are the right size.
In order to make the Ozobot recognize the line,
it should be about 5 mm wide.
2. Make sure your lines are consistent.
If the line gets wider or thinner,
Ozobot may loose the line and stop its motion.
3. Make sure your turns are curved gracefully.
If the continuation of the line is in parallel and too close,
the Ozobot robot may see it as the same line
and won't be able to make the turn.
4. Make sure you don't have sharp curves.
5. Make sure your color coded sequence is positioned correctly.
The sequence should be surrounded by
Black lines longer than 2 cm in length.
All colored components of the sequence should be
the same size and length,
without any white space in between or overlapping colors.
6. Make sure the coded sequence colors you are using are not too dark or light.
7. Make sure the sequence is at least 5mm wide
and no longer than 6 mm in length for a single color.
8. Make sure your color coded sequence is well seen by the robot.
Keep codes on straight lines away from the corners,
away from intersections,
and at least 2.5 cm apart from each other.
9. Make sure you are using the correct markers
10. Make sure your robot is fully charged.
If Ozobot blinks red, then the battery needs to be charged.
11. Make sure your Ozobot robot is calibrated.
12. Make sure your Ozobot robot is clean to allow his sensors a good visibility.