Let's Make Robots!


Simple object/light avoidance, and line follower.


UPDATE 19/11/2010

As promised, I've added a short video of some of the functions I can use RDP-01 for.

I know they're not brilliant, but at least I am beginning to get a little understanding in electronics and programming. I'm especially pleased that I have managed to get him to follow a line (although the wife's not best pleased, as the tape left a residue on the kitchen floor!).

The programming leaves a lot to be desired, but I'm learning. I can't seem to get the FritsLDR function to work properly, it almost works, but obviously my programming in C isn't good enough. I'll try again when the Picaxe arrives :)

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OK, so I "Pimped My Bot" :)

Strictly speaking, I suppose this is not really a 'new' robot, as the chassis I built for my first robot has been used, but it is far removed from that one.

I have given it a complete makeover, and have added flashing LED's to make it more visually appealing. I've also added a couple of LMR stickers, but the glue doesn't seem to want to stick properly.

It uses a SharpGP2D12 range finder for object avoidance in the main. I have tried to implement fritsl's visual light avoiding technique, but as yet have not got it to work properly. However, I have noticed that if I use the Sharp in conjunction with the red led's flashing, and the photoresistors at the front pointing at an upward angle, as a backup object detector, the bot actually avoids chair legs (!) and will extricate itself from under the table with a forest of legs. I still want to get fritsl's idea working on it's own, though.

The 2 photoresistors at the front are mounted in poseable tubes, so can be pointed at the floor for photovore/phobe applications. (By the way, what is the difference between a photoresitor and an LDR?).

I will post a video showing all the various functions after the weekend.

I have also mounted 2 tubes at the front underside, approx 4mm from the surface, which will have photoresistors in them. Forward of those will be 2 very bright led's pointing at the surface immediately below those tubes, which will hopefully give me line following capabilities. (I did try 3mm led's, but they weren't bright enough, so 5mm are on order.) Incidentally, the tubes are a ball point pen case.


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I laughed at the revolving presentation platform. Beautifully under engineered.

I don't think there's difference between "photo resistor" and "Light Dependent Resistor". I have even seen other names. They all work in the same way. More light gives less resistance. The gradient may vary, not the direction of the slope.

"I laughed at the revolving presentation platform. Beautifully under engineered."

A throw back from setting up small RC Helicopters, with the addition of some cotton (no motorised turntable for me!)  :)

great looking robot! good pimping..

I like those details! Like the inside of the wheels being yellow, and the "chicken wire".

that video makes me also smile :D

keep up the good work.


Love the robot, and absolutely digg the showreel platform! I always wanted to make one, acutally a complete picture box with light and rotating thingey and all, just never got to it. Now I will have to copy you one day ;)

And sweet light show :D Nice!

I'm actually quite embarassed by the video of the turntable, now. It looks to me something like a silent cine film from the 1940's =)

Great looking and functioning robot so far!

the light following LDRs might work a little better if you angle them outward slightly, so the left one points more left, etc.   and turn 22 degrees instead of 45.

but who am I to make suggestions, I've never made one...    :-)


Well, it looks like you are well on your way. This is a wonderful little robot and I hope that you get to build more in the future and that you will continue to update us on your progress.

Lots of plans for the future, don't really know where to start :)