Mindstorm Altermative Question

Is the Mindstorm kit from Lego the only way to build a robot with
Legos? Is there a way to do it for less than $200? I am a
programmer, not a mechanical engineer, but I am not afraid to tackle
building things.
Reply to
jm
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No, actually a number of people use Legos parts and use their own MCU board instead of the RCX brick. The problem is usually you already have a Mindstorms set or two or three in order to have all the robot parts and sensors and stuff. The Legos Spybots are a cheaper way to go, if you just want something simpler. These are programmable using NQC or Legos Mindscripts. There are several under $200 robot kits available, probably one of the best of them is the
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MARKIII robot for $92.00. Parallax Inc just recently started a sale on some of their robots and they have several now that are under $200
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always are good deals as the stuff Parallax sells is heavily documented and supported. You can't go wrong with the BOE-Bot as a general purpose learning platform.
Reply to
Earl Bollinger
Non LEGO: You can get a very decent robot kit for about $100, but the electronics are usually in kit form. If you're okay with a soldering iron these might be a good alternative. For starters, check out:
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These bases are expandable, but not like LEGO, where you can build different snap-together creations. If you really want a LEGO-type systems, you can still consider the Mindstorms route. Try eBay for a used set.
Or: for about $120 you could get an already-soldered OOPicR or similar controller, two standard R/C servo motors (you need to modify these for full rotation), some wheels, and a LEGO-compatible servo mounting bracket from my small robot parts company, Budget Roboptics
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-- these attach to a LEGO Technic beam so you don't have to glue anything. You can then use your existing LEGO parts and build whatever you want.
If you need more parts, consider MEGA BLOKS or Hasbro's new BTR line, as they offer lower-cost parts kits that will connect to LEGO. This self-built system would actually be more flexible than Mindstorms, with more powerful add-on possibilities.
-- Gordon Author: Constructing Robot Bases (Now Available) Robot Builder's Sourcebook, Robot Builder's Bonanza
Reply to
Gordon McComb
It's very difficult to do *anything* with Legos (which, near as I can tell, are made from 24K gold with a thin plastic covering) fro under $200...
You can certainly buy a stack of Legos and a small single-board computer (see Circuit Cellar magazine for a near infinite list of suppliers) and make a robot. But, unless you've got some pressing need to build it from Legos, I can't quite see why... Note that in our sophomore assembly language programming class we take exactly this approach (using Fred Martin's HC11 Miniboard); the reason is so the students can have a lot of platform freedom, and we can reuse parts every semester.
One of these days I'm going to have to write up my "perfbot" -- a stack of cheap perfboard from Radio Shack with aluminum spacers separating the layers. Cheap, easy, effective.
Reply to
Joe Pfeiffer
Good advice from all. If I were starting out and wanted to go the "kit" route I would look at Gordon's stuff.
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and just use your choice of micro, I've purchased wheels and materials there, good stuff and about as inexpensive at is gets.
Also check ebay for used BOE-bots, there's usually one up for sale just about every week it seems.
-Dave
Reply to
Dave
I received the Lego Mindstorms Kit and I was not very happy with it. Don't be afraid to tackle the mechanics yourself. I would suggest taking a couple of hobby r/c servos and gutting the electronics. This will give you simple and easy to mount gearmotors. Mount them to a perf board, On the perf board with double-sided tape attach a 9v battery (rechargeable) And also attach a bread board. Maybe a caster in the front. Now you've got plenty of space to experiment, including a breadboard and power supply. And when you've taken this platform to the max, You'll know exactly what you want different and what you can do to make that happen.
Good Luck. Rick-
Reply to
Rick Cassidy
I would suggest not gutting the servos, if they can be bought or modified for contiuous rotation.
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sells pre-modified servos.
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sells easy to modify servos too. Many servos can be modified, some easy, some hard, some no way to modify. If you use the servo electronics, it saves you from having to learn how to use a motor controller or to wire one up. Basically you have the MCU pulse the servos using the RC control pulses and the servo rotates nicely. You easily have forward, reverse and stop. It keeps your first bot on a much simpler level to get started with.
Reply to
Earl Bollinger
[snip] : The Legos Spybots are a cheaper way to go, if you just want something : simpler. These are programmable using NQC or Legos Mindscripts. [snip]
Earl, Spybotics are programmable via NQC? I've got Ralph's Spybotics book, which doesn't even hint at that - What sources are there to program these cool little guys with NQC?
I have two Mindstorms sets, and I'm not in the least disappointed with them. Sure Legos are more expensive than Megablocks, but they work well, don't warp, yaddayadda. That Mindstorms brick is a pretty nice package.
IMO, DLC
Reply to
Dennis Clark
Well, Ralph is a pbForth kinda guy, naturally enough. My understanding is that you can't reprogram the Spobotics brick firmware, but both Mindscript (which isn't bad) and NQC will work. Dave Baum has some Spybotics information on his site, which is now baumfamily.org.
-- Gordon Author: Constructing Robot Bases, Robot Builder's Sourcebook, Robot Builder's Bonanza
Reply to
Gordon McComb
[snip] : This site has all the info you'd want. :
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Thanks Earl!
DLC
[snip]
[snip] :> Earl, Spybotics are programmable via NQC? I've got Ralph's Spybotics : book, :> which doesn't even hint at that - What sources are there to program these :> cool little guys with NQC?
Reply to
Dennis Clark
Well, if you are a fanatic you could reprogram it. It uses a Hitachi MCU (Renesas?). So you would have to open the Spybot up to get at the board, then figure out where to hook up the JTAG or ISP programming pins, using something like a connector and wirewrap wire. But they made it harder by putting the MCU under an Epoxy blob. It looks like they cost reduced it by wirebonding the MCU directly to the PCB. Which then makes it tricky to determine which chip they used. But since it is so compatible with the regular RCX brick, I can make an educated guess that the MCU is the same as in the RCX. Then you can buy a $2,000-$3,750 C compiler IDE to program it with (don't forget the $800 programmer module). Fortunately, Mindscripts and NQC both work great on it. Both of these programming languages are free. Besides they put all the great RCX state machine stuff and RTOS into the MCU, it's a shame to waste it all.
Reply to
Earl Bollinger

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