Let's Make Robots!

Robot Buggy

Follow Light

My First Robot

It's a simple modified RC buggy, designed to follow light.

Picture (Before the Tragedy)




I was having Test Run, suddenly it missed light and baang into the wall! The front tire broke! As you can see from the picture, the front bumper is already broken, the tire directly hit the wall and broke. For your information, this RC Buggy is about 10 years old, lol. Yeah, it is my elder bro's. I asked him if I could make Robot out of it, he said, yeah why not. I don't have enough money to buy new RC car. Here's the broken tire picture


 So what did I do?

I didn't have money to buy new RC car, so I had to make my own steering mechanism. I had servos(small ones) I don't know but they don't seem to work with my Arduino Mega, they do, but they are very slow. I had posted onto Arduino Forums, but the problem is still unsolved. So I used High Torque Motor that I bought from Sparkfun.com. I mounted the wheels onto this High Torque Motor. For turning I calculated the time taken for the DC motor to rotate about 45' degrees, it was around 200ms. Through this, I was able to determine the position of the motor. I know, if the current drops, it won't rotate 45' degrees. I know this, but I didn't have any other choice. It works! 

Here are the pictures of new Steering Mechanism.




Looks like a futuristic buggy right?



This is my first ever Robot, I know it's messy, all the wires running around, sorry for the mess :)

If you see the video, the buggy can't get the light when it's far from it .This is not a bug or fault. I intentionally did this, and it only moves forward, when it detects light on either side. When the light is balanced, it stops.

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Looks promising. Will be waiting for pictures and videos when you get something shaped out. Good luck!
Is that a servo at the front to control the steering?  I'm interested in trying that approach out, instead of having two motors and steering with those.

That's not a servo. That is a simple High Torque DC Motor


What I have done here, is send a pulse to the motor for about 200ms, which makes the turn, and if I give the same pulse, to the other side of H-Bridge, the steering is back to the centre. Likewise, I did it for the right turn. I know this is not a good way to do it. Since my servos aren't working, and in my country, there are no servos available to buy.

That's a great solution for problem and the limitations you had. Great work!

I'm really surprised how well you are able to turn reliably with a regular high torque motor. 


Yeah, I had been tweaking the code for like 3 hours, then I was able to get the thing working correct.

Wow! I love light followers!!  

Great job with the steering system!! If you add more weight on the front you can have better steering performance, but this is me talking maybe you like the way it is!!   ;)

Keep it going

The front motor itself has a good weight, so it kinda balances the CG. It works great! I didn't even thought of working of DC motor as Steering would be that cool :)

"..I didn't even thought of working of DC motor as Steering would be that cool.."

me neither!!  :D

If you can get a potentiometer from somewhere, you could work that into the steering somehow to add positional feedback, then you could specify a position for the pot to get to, and have finer grained steering control that way - Essentially, creating your own servo with an Arduino instead of the internal controller
Yeah, but I am totally noob at Servos :P lol I need to learn more about them, as they are not available in my country, so I can't learn them.