Let's Make Robots!

FredBot 1.0

Line Following

Hey guys i finally got around to finishing my first robot. Thanks everyone at LMR it would still be in hundreds of pieces without the help from you guys! Simply: it follows a black line. it looks like a bunch of wires and a few chips bluetacked onto a piece of wood but apart from the looks i think it works pretty well. i hope you guys like it, any tips or modifications would be appreciated.


I just added another video.

the original video shows the robot with gear ratio 334.2:1 the new video shows the robot running at a gear ratio of 114.7:1.

this makes it a lot faster but it sometimes slips off the line, i also had to increase the operating speed from 8Mhz up to 16Mhz.

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Fellow Aussie. I'm sure it would make for an interesting walkthrough on how you made your homemade IR sensors. Do you think you could add some more detail to this post. Also like some pictures of your boards and what each one does. It's hard to see clearly but it looks like you have at least 3 on the chassis. And an underused breadboard? Do you have further plans for this bot.

Go to town. I like to read.  ; )

I would like a closer look at those IR sensors as well. Great job on your robot!

This is the circuit that i used to make the IR Sensors. Pin C.0 could just be any ADC input or digital input.

The ciruit boards are the PICAXE 20X2 project board, a homemade board for the L293D just to make it easy to hook up and on the breadboard are the circuits for the IR that are shown above.

One very interesting thing to do with any linefollower is PID control, great programming challenge and it's fun to play with the values to see how fast you can get the bot to go without losing the line :)

Thanks for the idea but what exactly is PID control?

Proportional-Integral-Derivative control



I didn't see it go off the line in the video. How often does it do this? Maybe you should get a bit of white timber to run your line on maybe the paper moving interferes sometimes. I used a sheet of particle board with white laminex to make my track.

It only comes off the line every now and then, i think the problem was that in some places the line is thinner and therefore the robot has less time to sense the line.

i added a bit more thickness to the line and it stays on a lot more!

thanks for the tip on making the track!