Transcript FIRST LEGO League Power Puzzle 2007

To RCX or To NXT:
That is the Question!
FLL - The Power Puzzle
2007
Presentation by V. “CyberGranny” Greene
Brics-2-Bots Lab
RCX (with RL 2.9)
NXT
Number of Motor ports
3
3
Number of Sensor ports
3
4
Rechargeable Battery System
No
Yes
IR Compatible
Yes
No
Hard-wire link to computer
No
Yes
Motor speeds
100
100
Sounds
6 beeps
infinite
Drive straight
No
Yes
On-board variables
64
100-1000
Display control
numbers
text, images, numbers
Number of stored programs
5
Infinite w/memory limit
On-brick programming
No
Yes
Uses new and old sensors
(No)*
Yes
*Can use the NXT Touch and Light sensors in RL 2.5.4 and all 4 NXT sensors +
servo motor in RL 2.9
+ Plus +
If you have been using it, then you can focus on the
new challenges rather than learning a new system.
The design of the RCX makes it more adaptable to
adding sensors/motors which are smaller.
RCX
You can build a sturdier robot - reinforcing it is easier
than the NXT.
Sensors
Rotation
Light
Touch
You can “piggy-back” your outputs & inputs, this frees
up additional ports.
(2 touch sensors w/same program instructions
2 motors running the same)
Programming - Easy drag & drop.
Fairness Bonus??? - On non-perfect scores.
- Negatives Uses alkaline batteries - Some rechargeable
batteries do not fit properly so it loses contact &
turns off.
If the robot is not balanced it will tend to drift, BUT
that can be compensated for in the programming.
Using the IR transmitter you can pick up stray
signals (So cover the robot when downloading &
turn it off when not downloading or running the
programs).
Battery strength affects performance when you
use timing.
Program wiring is sometimes a problem, but
troubleshooting will show you where the broken
wire is.
The RCX will soon be discontinued.
+ Plus +
Interactive Servo Motor offers 3 options of
measurement control: timing, rotation, & degrees
which can easily be switched for the best
performance.
NXT
Sensors
Ultrasonic
Sound
Light
Touch
Rotation/Motor
Ultrasonic sensor for measuring distance &
movements of objects.
Programming is similar to The RCX - Drag & drop,
however, wiring assigning values, conditions, etc. is
easier.
You can use RCX motors, touch, & light sensors with
the NXT.
Uses batteries or a battery pack that makes
recharging easier.
No stray transmission pick-ups.
- Negatives The NXT has extras downloaded, taking up memory
that you might have to erase in order to fit all your
programs on.
The robots aren’t as sturdy as the RCX & reinforcing
is a bit more of a challenge.
You can’t “piggy-back” sensors/motors, except
maybe with the conversion cable when using RCX
sensors/motors.
The Ultrasonic sensor might react with other
ultrasonic sensors.
Turning on, finding, & running programs is not as
easy as the RCX - it involves extra button pressing (a
slight time issue at the FLL tournament).
The display can be hard to see, because of light
reflection.
Excellent manuals for the RCX & NXT
http://hightechkids.org/?2-1-1054
Video tutorials for the NXT
http://www.ortop.org/NXT_Tutorial/index.html
Book
LEGO Mindstorms NXT-G Programming
Guide by James Floyd Kelly - Apress
So which one is better RCX or NXT????
That will depend on what you need the robot to do!