I forgot to tell you that the light sensors are not all equal in front of god!

For instance white is = 68 with one sensor and = 69 with the other sensor that is an issue from PID standpoint. I had to adjust the error value factor to 0 when I have a difference of 1 between my two sensors! at best I should maybe always do -1?

Steve Hassenplug is a master LEGO robot builder and has a great site. Take at look at Steve's site at http://www.teamhassenplug.org/.

Here are some other videos / pictures of line followers. Mostly from Steve.

http://www.youtube.com/watch?v=w5dTUlj3HJQ -- a great video of a really fast Mindstorms (RCX) line follower. Three light sensors.

Also http://www.youtube.com/watch?v=4s9JkMAPFtI

And download the movie at http://www.teamhassenplug.org/robots/legway/ and play to see a balancing robot following a line. NOTE: I had to download the file to my PC and then open it. When I tried to view in Internet Explorer all I got was audio.

Also http://www.youtube.com/watch?v=GYB6yfzavKo -- line follower navigating a maze.


http://www.geocities.com/laosoh/robots/linefollow.htm -- with a pen trace of edge following.

Thanks guys, it is fabulous to see the quality of responses in this thread.

Another question I have relates to whether anyone has experimented using the HiTechnic colour sensor to follow a line? I guess it would invalidate the use of PID, but 2 of the sensors could be used in a more traditional/simpler line straddling formation.

Without having to purchase and test them myself I was hoping to get some feedback as to the likely strengths and weaknesses of using normal NXT light sensors Vs HiTechnic colour sensor to follow a line.

Thanks
James

To admin (If this should be moved onto a new thread please move it)

Hi,

I have two HT Color sensors and it is in my test plan to use them with my robot... I have done some tests and they return a value that is linked with a color. I have to do more test...

cu.

Hi, This post is very informative, however I would like some specific information. If someone can help me then please send me a private message. Best Regards

Here you can see the speed of a very naked robot (not lego)

http://www.youtube.com/v/25WaKtTpuWU

camera is badly shaking and I'd prefer the motors noise to this music but you can see the speed of it.[/url]

very impressive. Is it a kit or you make it from scratch... like from bread board, make your own circuit board and all?