Stingray vs NXT 2.0 Robot
USMCinfinity
Posts: 150
I'm looking for a robot to be the base for projects like a light follower, GPS, line follower, stuff like that, my question, in reality which will be more cost friendly and easier to actually get those projects done with? The NXT already includes most sensors needed while the stingray comes with nothing [noparse]:([/noparse]
Comments
My 8 year old plays with that, learned to program it, too. So if you're starting out at the very basics and don't plan on learning much very fast, then NXT might be the way to go. But if you want to start learning on something upon which you can build and build and never possibly stop learning and growing, then I'd pick a Parallax product, especially something based on the Propeller. If you learn to use the Propeller, there's no limit to what you can do, what sort of sensors you can interface with it, or invent some of your own.
Enjoy your new Stingray!
NXT Good Points
* You can build a line follower in an evening. Take it apart the next day and build a walker. Since you don't have to mill parts you can quickly prototype stuff.
* The electronics are essentially goof proof. If you plug a motor into a sensor jack nothing bad happens. You can't accidentally reverse polarity. You can turn an eight year old lose with it and they'll succeed.
* The brick is a 32 bit ARM with LCD, speaker, and buttons. It's a good micro-controller.
* The number of things people have done with the NXT is mind boggling and they generally document what they've done, so you're a Google away from Lego goodness.
* Their servos can be controlled from other microcontrollers if they have an h bridge. They have built in quadrature encoders with 360 pulses per rotation. Not too shabby.
NXT Bad Points
* The G language is somewhat alien if you know how to program. However, C and Java compilers are available.
* The Technic building system takes getting used to. Build a bunch of stuff using plans to get a feel for how the parts interrelate and strategies people use to solve common problems. Learn about trusses and the 3, 4, 5 right triangle, its the only way to build anything strong.
* There is a lot of play in Lego linkages, so expect some slop. Some people pre-load linkages using a rubber band. Basically it is a bit rube goldberg-esq.
* There are not enough Technic parts included. You can't buy a bucket of Technic parts either, but instead have to buy sets to build things. There is a healthy used market on E-bay, but there is price gouging for certain desirable parts. I don't get what Lego is up to with this.
* The number of ports are limited, but because it uses I2C you can multiplex ports. But the adapters are after market.
Last, but not least.
* I had to buy more Parallax gear because my kids don't want to do daddy boring stuff. We tend to build robot tanks that use their sonar to attack things. Robot alligators that use their sonar to attack things. Robot llamas that spit balls at people who their sonar determines are too close. There's kind of a pattern here.
Quick final thought. The NXT goof proofness means a lot of details are being hidden from you. I learned a lot more about serial I/O, RCTime, and servo pulses with the BS2 then I did with Lego. The down side is that you can goof up and burn out a part if you plug it in wrong.
Post Edited (Martin_H) : 7/29/2010 1:51:04 AM GMT
First, I've always paid via a credit card. I didn't even know Parallax also uses PayPal.
Second, are you sure you even need to start out with a robot kit? For the Propeller chip, there is the Propeller Education Kit, which has all the things you need to walk through a lot of simple projects that can teach you how to use the Propeller's multiple processors, etc.
There are a couple versions of it:
www.parallax.com/StoreSearchResults/tabid/768/List/0/SortField/4/ProductID/415/Default.aspx?txtSearch=propeller+education+kit
www.parallax.com/StoreSearchResults/tabid/768/List/0/SortField/4/ProductID/506/Default.aspx?txtSearch=propeller+education+kit
From there, it's relatively easy to build your own robot, shape it anyway you want, use whatever kinds of motors you want, sensors, etc.... or.... then buy the Stingray kit and build that, I suppose. So, in other words, perhaps you might want to learn how to use the Propeller chip first, then the sky is the limit on what you might want to do with it.
Just my 2 cents worth.
http://www.yaaarc.org/wiki/index.php?title=PropBot
Not to shabby and pretty cheap too.
You have the most flexibility if you go with the DIP version since the PropStick already has some features hardwired to it, for example the EEPROM. But if you're in a hurry, then the Propstick will certainly get you started and save you some of the initial wiring that the DIP version requires, and once you get rolling, buying a separate DIP chip version of the Propeller is no big deal. Either way, I doubt you'll regret it. But I've never worked with the PropStick so I'm not the best judge of it. You might post your questions on the Propeller forum and get lots more opinions.
have fun!
Rich H
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The Simple Servo Tester, a kit from Gadget Gangster.
The webpage for the DIP says "Product is expected to ship on 8/6/2010". That's August 6 here in the US.
Well, not exactly. To use the DIP, you would need to also get the crystal, chips for voltage regulation, etc. Those items don't cost much, but it's something you would need to support a DIP.
Why not order the DIP version and bite the bullet for 10 days or so?
I'm not sure if the manuals are identical, but Parallax has everything downloadable as pdfs, so you can even read the manuals before you decide which products to buy. That's the great thing about this company and their view toward education.
I would definitely get one of the education kits or the demo board to start out. I have a Stingray and it's a great robot, but I think it's better to start off simpler to learn the Propeller first.
The path I took with Parallax stuff was starting with a Boe Bot a few years ago, I think it's a really great platform to learn all the essentials of robots (motor/wheel control, sensors, and making something that drives around and reacts to the world). Then I got introduced to the Propeller via the Hydra board, it was great to learn how to program the Propeller on, but I couldn't really add sensors or other stuff to it easily. So, I got a Professional Propeller Development Board, and I love that thing. You can wire up anything on that board to work out ideas or test circuits. After I was already pretty familiar with programming the Propeller and hooking things up to it, I got the Stingray.
Parallax has a lot of documentation and examples built up for the BoeBot and the Propeller Education Kits, and so on. The Stingray is still relatively new and doesn't have as much stuff available for it yet. Eventually, they'll have a lot of stuff for the Stingray that will make it better and easier platform to learn robotics on, but until then, it really more of an expert level product.
So if you aren't already familiar with robots and making them work, I'd recommend getting a BoeBot to start (at least until the Scribbler 2 comes out later this year) with robot stuff. You can upgrade the BoeBot to a Propeller based control board later too.
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Check out the Propeller Wiki·and contribute if you can.
Woops, looks like you would also need a Prop Plug, which is also out of stock. [noparse]:([/noparse]
Rich H
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The Simple Servo Tester, a kit from Gadget Gangster.
Post Edited (W9GFO) : 7/29/2010 4:55:16 AM GMT
Gadget Gangster has the Prop Plugs in stock. There are also several Propeller boards there to choose from.
Rich H
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The Simple Servo Tester, a kit from Gadget Gangster.
Have we succeeded in getting you to spend money yet?
Post Edited (Martin_H) : 7/29/2010 11:47:25 AM GMT
I'd wait for that one.
"Hither and yon". PJ, you crack me up!
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·"If you build it, they will come."
Post Edited (erco) : 7/29/2010 4:32:00 PM GMT
What exactly are you trying to "feel" ?
Since we used the NXT structure for the Light Follower very little soldering and screwing was done, so I'm kinda scared as to how to build a robot, I hope the BoeBot is user friendly! haha