What is the trick with the line follower sensor?

#1

Hi,

I am just trying to work on a class project which uses the line follower sensor.

I have drawn a big map of Australia, with white paper and black marker. The line is equal thickness to the example mat given with the box.

It is detecting some black lines in some areas but not others, very weird!

Thanks for any help!

#2

Are you running the program from within mBlock or is it uploaded to the mBot?
Can you post your code?

#3

Hi,
Just using the mobile app with line follow option turned on.
Works fine for the supplied poster, but my own it works on some parts but not others (equal darkness and equal thickness of the line).

#4

If the sensor works with the supplied poster, it should be okay.
From the learn website for the line follower sensor. There is Principle analysis for this sensor:

Pasted image1305x300 18.5 KB

I suspect if the darkness on your own poster can absorb all the infrared light.

Besides, there are two sensors on the Me line follower module and there are two leds corresponding to the sensors.
When the sensor detect white floor, its corresponding LED will lit up Blue. If it detect the black floor, the corresponding LED will be off. You may test all the back parts on your poster by this way.

#5

When I create line following diagrams I will either use wide (2.5cm / 1 inch) black electrical tape or black cloth tape to ensure that I have a consistently high contrast. Using markers to do the diagrams resulted in inconsistent shades which did not work as well for me. As @tec_support mentioned, if it works on the poster then the issue is likely not the sensor.

#6