Line Following Problem

i already had a working line following program and all i did was change the line and the floor. i got the new values for both the line and the floor and put in the new values but my robot only goes strait. everything in my program is spaced right and it should work but i have no clue why its not. any help or suggestions would be greatly appreciated.

Sure you got the right values in the lighting conditions your robot is working in? Maybe the line doesn’t contrast very well with the ground?

i tested the values and i changed them and now the middle sensor was working but the left and right wasnt but now when it reads the tape it stops and only the right side moves but its in reverse

Without seeing your code, it is going to be hard for us to do anything more than offer guesses.

  • Dean

If you already had working code, then the only thing that should have changed is the threshold value. Go back the original code, and put the new “value” that found.

And if that still doesn’t work, then it might be physical conditions like proper lighting and line/floor contrast.

I would still recommend posting your code if you think that is the issue.

ok ill post up my program but how do i post it?? ive never done it before…

If you are using text based code, like RobotC or MPLab, then just paste the code.

If you are using EasyC, then you might wanna do a print screen, or upload the code somewhere and offer the download link on the forum.

  • Sunny

You can also attach your project to a forum post.
(Use the little paper clip icon on the posting form to add files).


  • Dean

easyC has a line following tutorial built in to the help file.

Getting Started → Adv Tutorial 1-6

Also, with the vex sensors using 1" wide electrical tape makes a huge difference.