Newbie needs advice on first bot

Other Hardware Robotics
1

Hello everyone!

Alright, so I'm completely new to robotics, as well as electronics in general. However, I am a techy-"geek" guy, so I'm not completely out of my comfort zone.

Here's what I'm trying to do.. I want to build a bot (preferably tracked) that can be started in a room/house, and map out the space in 2d. After that process is done, I want it to be able to locate it's "home" - charging base - and then randomly move about.

I'm guessing a modified wall-following bot would do the trick. My question is, what hardware/sensors should I use?

Again, I'd like it to be tracked, but there's a good amount of slippage with this type of setup, yes? and getting precise readings of the space is important. Is tracked not a good idea?

Also, I know I'd need two motors and motor shield. I was looking at the AdaFruit board, though assembling it is a little daunting.

As far as the sensors go, I've seen variations using 1 ping sensor and that's it (i think), or some using up to 7 pings, or multiple IRs. Are pings more precise?

Also, for storage of the data, an SD shield would be needed too?

I have big plans for this (I like to learn by jumping into the deep end), but I figured I'd try to scale it back a bit at first.

I realize this is a bit unorganized, but I think you can get what I'm trying to do?

Thanks!

2

You might want to try using ultrasonic sensors to help your bot navigate, or at least keep from crashing into things.
These units are easy to use, your serial monitor will give real-time data.

Also, accelerometers will be useful if not essential. Try these guys, I've gotten several components from them, good documentation, easy set-up. They're on Amazon.

https://www.virtuabotix.com/feed/?p=209&wpmp_switcher=mobile

3

What would the accelerometers be used for?

Forgive my ignorance...

As for the ultrasonic sensors, that was the "pings" was referring to. I picked up one of these for $20, though I see the ones you suggested are considerably cheaper.

4

Marroond:
What would the accelerometers be used for?

Forgive my ignorance...

As for the ultrasonic sensors, that was the "pings" was referring to. I picked up one of these for $20, though I see the ones you suggested are considerably cheaper.

You could also try the line following bots:

http://www.botbuilder.co.uk/codeandprojects/bbline/index.html

5

Any other insights?

Am I on the right track with what materials/hardware I'd need?

On the programming side, how would I get the bot to keep track of the limits of the rooms? Ideally, it'd make a record of every point that it was, say, 9 inches from the wall. But for it to be able to do that, it'd have to create a 0,0 spot? and then plot the coordinates off that?

lol Is this making sense at all?

6

If you are set with tracked treads (Which is a good idea if your bot encounters a rouge sock) prepare to find your bot immobile occasionally because a tread popped off. My personal experience is with the tracked kit by Tamiya from RobotMarketplace.com

I was using the included gearbox and the faster I went the more unpredictable the treads became. Also for future refrence the tank treads couldn't conquer grass very well.

A behavior I noticed my Rovio acting out when it needed to charge was aligning a pair of infrared sources, one shining on the roof and one on the unit. As far as mapping out the room? Let me know when you figure that one out lol.

7

I'm actually planning on using either these:

Or these:

The only difference being the first ones are rubber, and the second are plastic (supposedly to travel over carpet better). I'm skeptical about the plastic ones, so I'm thinking of using the rubber ones with the nubs. Good thinking about the socks! I wanted treads out of pure aesthetics, but it's nice if they're for a reason. lol

There's a guy on instructables that posed a how-to on a rescue bot, that does almost what I want. His mapped out things on a grid. I'll probably end up contacting him directly on this.