Mindboards

Hi all,

I am a IT that want to play with robots. But I dont have clear if is better to buy a mindstorms or an arduino kit.

I consider Lego a bit expensive and also it seems that it is very old! (2006 nxt or 2009 nxt 2.0)
By the other hand, arduino could be more dificult to play with.

I suppose that if I ask you in a mindstorms forums everybody will tell me that mindstorms if the best solution.

But anyway, Is it worth buying lego mindstorms?

I would not like to buy a lego kit and some months later a new release appears in market!!

Any comment will be appreciated , .. And sorry for my english!

walduss wrote:Hi all,

I am a IT that want to play with robots. But I dont have clear if is better to buy a mindstorms or an arduino kit.

I consider Lego a bit expensive and also it seems that it is very old! (2006 nxt or 2009 nxt 2.0)
By the other hand, arduino could be more dificult to play with.

I suppose that if I ask you in a mindstorms forums everybody will tell me that mindstorms if the best solution.

But anyway, Is it worth buying lego mindstorms?

I would not like to buy a lego kit and some months later a new release appears in market!!

Any comment will be appreciated , .. And sorry for my english!

It all really depends on what you want to do.

Here's a list for consideration:

MindStorms:

PROS:

1. Easy prototyping.
2. Massive support.
3. New sensors with drivers come out every couple of months or so.
4. Backwards-compatible. Pretty much all of the different MindStorms systems can be used with each other.
5. Reusable. Yes, a NXT 2.0 may cost $300, but that's the average cost of a "normal" robot. With LEGO, you can reuse that $300 as many times as you want.

CONS:

1. Plastic is not the sturdiest material.
2. Accuracy of LEGO MindStorms is not as good as "normal" robots.
3. Yes, LEGO stuff can be overpriced.
4. Programs run much slower on the NXT, RCX, etc than on normal MicroControllers.
5. Less sensors are available for LEGO (unless you made your own.)

Arduino: NOTE: These are merely observations based on what I've read. I have neither used, or own a Arduino.

PROS:

1. Somewhat easy prototyping. Doing electronic circuits with a Arduino is exceptionally easier than other controllers.
2. Easier programming enviroment. The Arduino language is easier to learn than say, C, Java, C++, etc.
3. The Arduino also has a lot of support.
4. You can use pretty much any sensor there is.
5. There are many, many, many "shields" available for the Arduino. Including one that allows it to interface with LEGO devices.

CONS:

1. It's more exspensive than using just a MicroController. Average price of a Arduino, $30. Average price of MicroController, anywhere from free to $10.
2. Umm, I don't really know any more, never having used it.

So, I would recommend MindStorms if your a beginner, or, if you want something kinda like MindStorms but not, then I would suggest getting an Arduino.

Lego in general is:

• Much easier to build mechanically
  more expensive than some other systems, but priced very well for a "prototyping" platform
  Made out of ABS, so it's not as rigid as some other materials

The NXT brick HW:

• Very robust, and all-in-one (battery box is part of the unit)
  Built in motor controllers
  sensor interfaces
  Bluetooth
  RS485
  64 x 100 monochrome LCD
  4 user-interface buttons

There are many programming options for the NXT. There is a labview based language called NXT-G (included with the retail NXT kits), several C based languages, a Java based language, as well as many other.
The NXT has a FW which provides a VM for the programs to run on. The standard Lego NXT FW (and all major NXT FWs that I know of) provides decent support for multitasking in a round-robin manner. Each task gets to run for a short time, and then the next task gets to have it's turn. You can have virtually unlimited number of tasks running in "parallel" (there probably is a limit, but I think 10 or so user-tasks seems to work fine). Because the programs run in a sort of VM, there is no way to directly access HW resources from a user-program.

The Arduino:

• is open-source completely
  programmed in C++
  IDE is (IMO) very buggy and picky
  is not a "polished" robot controller by any means. In order to connect sensors or motors, you have to build an interface, or else use what's called a "shield" (a PCB that plugs into the Arduino to support some accessory function, or provide some interface). You also need to provide a separate power supply (battery box).
  The Arduino does not run a FW (although it does have a boot-loader), so there is no multitasking. In many cases there are ways to get around this, but it's nothing like the NXT.
  It's true that code can be executed in a very speedy manner, but that's because it's only doing one thing at a time (running the user-code), and not taking breaks to update things like the motors, sensors, LCD, BT module etc. in the background as the NXT needs to do.
  Complete direct access to all HW resources, and full support for pointers etc. that the NXT FW doesn't allow.

I have had NXTs for over 3 years, and have built many custom sensors and interfaces for them. I have had Arduinos for over a year, and have done many things with them as well, including writing several libraries. I have combined the 2 systems a number of times, to make very universal platforms.

To sum it up with my opinions: The NXT is far better suited as the main controller of a robot. The Lego system provides a way you can build a complete robot in less than 30 minutes, and completely reuse the parts later. The Arduino certainly has it's place for me though. It is great for single function stuff, and for interfacing directly with analog, logic, and/or digital electronics.

Depending on what it is you want to do, you should check that the Arduino has sufficient memory available. Many of the devices only have a few Kb of RAM (had a quick look and the largest I could find was 8Kb but there may be other devices with more), which if you plan to do things like build maps etc. may not be enough. The NXT has 64Kb of RAM (which these days may not be considered that much)...

Andy

By the time you buy an Arduino, lcd screen, input devices, sensors, motors, cables, programmer, etc, you will probably spend more than if you had bought a used NXT set from ebay.

I looked into different systems and ended up with the NXT because it was all in one box and already designed to work together.

I still look at picaxe, etc from time to time but have always decided to stick with LEGO.

As Andy said, the NXT does have 64k of RAM, but only about 32k is user-accessible using Lego FW.

The Uno has 2k of RAM.

Thanks for all your comments,

By the time been Lego Mindstorm is my favorite choice.

Something important to me is the fact I dont have too much free time, so it is better for me a kit easy to build and easy to program.

Now I need to have enought money , I hope come back soon with my lego kit.

I will continue reading this great forum.

Thanks

Hi all,

I have bought it. .... I hope it will be delivered in 2 weeks

Thanks for your advices.

See you soon with more questions!!

Great! Can't wait to see what you build!