Michael

Thanks.

Q: wiil it be possible to have two NXT’s talk to each other?

if not I will stick with an RCX

1) NO backwards compatiblity. You will need ALL NEW MOTORS & SENSORS. For people with an investment in the current mindstorms it leaves them out in the cold. NICE GOING LEGO. But, I can forgive this.

2) NXT

a) – too little ram, too little flash. There is just NO REASON in this day and age to have the device be SO limiting. You won’t be able to do any meaningful sampling unless connected to another device to dump data so no “long autonomous” missions :^( WHY?

b) It looks like they copied the iPod design. While SOME people love the studless design, there’s NO QUESTION that mounting the old RCX was much easier than mounting this thing will be. I could forgive this, but it WILL be harder for kids to work with.

c) Buttons – when trying to mount this inside robots, the buttons are all clustered around the CENTER of the thing. At least with the RCX, the buttons were near the edge so you didn’t have to have access to the center of the unit as much. AGAIN – that “iPod look”. Some designs won’t be bothered by this, others will!

What they SHOULD have done was to provide remotes (even as an option) that could be KEYED to a specific NXT module (how about setting an 8 or 16 bit code so the RC won’t accidentally control a different one – then these codes could be apportioned out PRIOR to tournaments and teams could set them up ahead of time). Or, it could be keyed to the serial number of the unit!!!

d) Keeping the limit to 3 outputs – WHY… No good reason.

e) Keeping the input to only 4 – NOT BAD, considering the motors now
have rotation sensors.

e) No way to run multiple sensors on a single port… This was one of the unique and innovative soloutions that kids USED TO have in FLL to create robots that would do things that worked well all the time.

f) Looking at closeups of the programming environment, it looks like RIS but instead of vertical programming, horizontal. Robolab is an EXCELLENT environment. Using big pictures on the icons “looks pretty”, but doesn’t allow a sufficiently complicated program to fit on a single page easily. Hopefully this was just a prototype and the real environment will be more Robolab like.

3) Studless Design. The previous poster thinks that using liftarms will fix his problem? WHY? Liftarms have ALWAYS BEEN AROUND. They could have been using them all along! I fail to see how having a new system will help that.

The FACT that his team did not learn how to PROPERLY brace beam that were stuck together does NOT mean that their new robots will be any better. I can say with 100% certainty, that beams with studs stuck together and BRACED are MUCH stronger than liftarms pinned together and, it’s easier conceptually for children to understand studded designs.

Our team has built MANY structures of both styles and if teams had a hard time with the beams, building a strong structure with liftarms will be a LOT LOT harder (try it!).

The question is: how well will THESE motors be balanced as far as torque output be? Do they have TRUE speed control, or is it once again, PWM. As everyone should know, PWM is NOT speed control at all – an unloaded motor will spin as fast at speed 1 as at speed 7, it all changes when the motors are put under load and the battery voltage changes! True speed control using a closed loop system would allow robots to go TRULY straight and, it would make it much easier for EVERYONE. Is this what we want? If the goal is to make things easy, why not just market a new ROBOT kit every year with building instructions that teams can purchase. Gone will be the TRUE engineering that comes with understanding the problem and overcoming it, not by having the answers handed to you! Will there be some issues to deal with – time will tell when we REALLY see what these kits are made of!

4) Motors – HUGE motors. I would rather have had SEPARATE rotation sensors and SMALLER motors so that some design tradeoffs and intelligence still had to go into building a robot. Having motors that are this huge, well, it violates the KISS principle, and it forces decisions onto builders that would be best left to the builder.

5) Sensors – they too look BIG. And again, the studless design – why??? To “look cool” – sigh.

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We have consistently been able to build FLL robots that score 400 points on the table using the existing parts. Our robots go straight (less than about 1/2″ left to right over a minimum of 4′ travel and a return to within 1″ of the starting position – I don’t think the NXT will help that!). Thinking that these new parts will help anyone make a better robot is, well, wishful thinking.

Watching lego leave their legendary “building block” studded design is sad. They are abandoning what made them great and, with the incompatibility, will surely be alienating those who have invested heavily in the current technology.

But, sheik is in, the iPod sells, and it appears that’s what they’re going after. Maybe I will be proved wrong, but there is no denying some of the facts I have listed above. I know that in the fall, both RCX and NXT’s will be allowed in FLL, but what about the next year?

What they SHOULD do is to have 2 separate categories to allow teams to compete against similar robots and NOT force teams to spend HUNDREDS or THOUSANDS of additional dollars to replace their current and still working mindstorms pieces.

Steve

It would be interesting to know more about the motor assemblys themselves.

1) The connection to/from the motors is said to be digital, does that mean that there are uPs in the motors?
2) If there are uPs in the motors, do they do the control loop or does the brick?
3) Is there a way to change the control loop?
4) The FAQ says the servo output is proportional to the velocity of the motor. Is there any way to get the position (or does it just feed off a single pulse for each revolution?)
5) Someone also mentioned that there are no gears in the kit, but some of the examples look like they would need a good amount of torque — does this mean that the motor is geared down in the assembly? The pictures seem to show that there may be room.

Hopefully, when LEGO starts the Developer Program, they will start to make more details known…

Cheers,

Keith