Wow! you sure got back to me quickly - and with a very full answer, thanks! I get it now...the sensors tell the robot which part of your map is light, and more importantly, which part is dark. Since you've programmed your robots to follow the dark parts (which is the black line you made) the robot works out where to go by steering away from the light areas and sticking to the black lines, right? I'll be interested to find out how you solve the problem of the robot stopping at crossing paths...make sure you put that info in the blogs when you figure it out please. Just another little question...how come the wheels don't slip when the robot is going around corners, or up hills? And finally, what are you planning to do when you visit Otumoetai Intermediate next term? Di.

Thanks for your comment Diana. We need the sensors so that the robot knows where to go. The robots use the light sensors because they can't see and the sensors help them to know where the line they need to follow is. The sensors tell the robot where the dark and light is and we programme them to follow the black line which is dark. The sensors shine a red light on the path and they sense how much light is reflected back. We got the robots to follow the path, but it was a bit tricky on the corners because sometimes it would just go straight instead of around the corner. We found sometimes that if the line was too thin or the robot was moving too fast it made it hard for the sensors to detect the black line so the robot didn't change direction. We had to try out different speeds and different brightnesses and sometimes had to make the lines thicker. The line had to be solidly coloured in for it to work the best. Some of our maps had crossing paths which made the robot stop and we're still working on a solution for this :) When the background colour wasn't white the robot sometimes got confused so we had to put masking tape on the edges of the black line to solve this problem.

Hi guys. I've really enjoyed reading all your blogs and seeing the photos of what you've been doing. Sounds like this Robot project has been a lot of fun! Did your robots follow the path like you thought they would? One thing I don't get, is why do they need lights and sensors? Di