Monthly Archives: August 2013


Your team is only as strong as your weakest link

At both my Capital Girls and Code Crackers meetings this week, I had moments of youthful disruptions that impacted the team’s focus.  Nothing major, just someone who couldn’t stop laughing or someone wanting to make the robot spin in circles.  Both the teams have high aspirations this season, and I am using that to drive focus, so we had a team talk about chain links.

With everyone’s attention, I asked them if they had ever heard the saying, “A team is only as strong as its weakest link”?  Some had heard the saying, and I asked them to explain it.  Turns out, no one wants to be the weakest link and the moments of disruption disappeared.  I also told them that a very important core value is “Have Fun”.  Laughing and extreme programming is fun, the key is knowing when it is time for fun and when it is time for focus.


Strategy Kick-off Week

The Nature’s Fury Challenge is out.  I am a believer in using tactile approaches with kids; it just works.  After watching the challenge video and going over each challenge at the board, each team member is given 10 sheets of paper.  Each team member gets their own color.  As the image above shows, the Capital Girls team members ranked their individual mission preferences and placed a piece of colored paper next to the mission.  Who knew the color of the paper each person got would turn into a core values challenge?  The paper has their name, mission rank and mission name.  This allows them to see who wants to work on what.  Using these preferences and meeting availability schedule, collected via Doodle, we can start looking at sub teams.

Typically we would divide the board into zones and have sub teams work on zones.  Given this year’s challenge, we are modifying this approach.  We will use element images courteous of TechBrick to makeindex cards.  The team will determine the types of attachments needed for each element and note the attachment options on the index card.  The index element cards will then be used to outline runs and element order.  A very tactile approach. Using the runs and schedule availability, I hope to have our sub teams defined.


The Code Crackers, as part of their strategy kick off, went on a catapult tangent.  They have the idea of catapulting all the emergency equipment, people and pets into the red zone.  I’m hoping they get catapults out of their system soon.  Again, the difference between boys and girls.




Code Crackers Robot – 2.0

After getting familiar with the challenge, the Code Crackers did deviate from their original robot plan to address the debris mission.  They now have a four wheel robot instead of a three.


Code Crackers Research Kickoff turned into a Sumo Challenge

The Code Crackers team hurt my feelings. I spent all this time creating this Nature’s Fury guide, and they just went in their own direction. In the end, their approach worked for them, and I got over it. They listed all the Nature’s Fury disasters they could think of, including going out-side the box with Solar Flares, Zombie Apocalypse and my favorite, Limnic Eruption. Using the process of elimination, they ended up on floods.

Once they were ready for a break, we decided to put their base robot to work.  I pulled out the Sumo Challenge Board and challenged them to find an object, push it out of the white ring without the robot going out of the ring.  Below is the video of a somewhat successful run.  The object was moved around and we had to keep legs out of the way.

Here is the program the team wrote. It did not work perfectly, but it gets the job done

Ultrasonic Following Program

Ultrasonic Following Program

G adding a third motor to the base robot

Code Crackers Base EV3 Robot

Like the Capital Girls, the Code Crackers built the base EV3 robot. They also elected to go with the big wheels for speed.  Being 8th graders, when they are focused they can get a lot done. For our robot build meeting, they split between builders and programmers.  The programmers built a music master program and base escape.

Below is the program the Code Crackers wrote for the music challenge.  They used notes, not sounds like the Capital Girls.  I am always amazed at the different solutions the two teams come up with when given the same challenge.  Sometimes they are very similar, other times they are polar opposites.

Master Music Program

Master Music Program

The Code Cracker’s Base Escape program has recovery logic incorporated. To start, I challenged them to stop at the line.  Once they had that master, the challenge was to stop at the line if the light sensor stop working (unplugged in this case).  At states in 2011, they had some big issues with light sensor and learned this recovery concept.  In 2012, the mentored the Capital Girls Too, who then used it for the Senior Solutions medicine mission.  Ironically, the mentoring team, 7th graders, learned from the 5th team.  Who was mentoring who?  The workshop challenges and programming posters have really advanced the teams’ programming capability.  They have learned that you can do some cool stuff with a loop, switch and logic block.  This is case where the solutions are the same, the only difference may be some block orders.


Capital Girls Building a Base EV3 Robot

Both my teams are very familiar with the NXT, and we had to to figure out how to get them familiar with the new EV3 platform in way that did not take up too many meetings.  Lego made this easy by including an instruction book for building a great base robot.  Our goal was to build a base robot to get familiar with the new set and begin learning the programming interface.


 The Capital Girls Team built the base robot in about 30 minutes, including using the wheels they elected to use when doing robot planning.  With 6 of the 10 team members at this meeting, we split into build and program teams.

The base robot the girls built was basic, with two motors for differential turning and a color sensor.  C, my daughter, later spent some adding a third motor.


Color Widget

While the build group was building, the program team wrote a program they called Master DJ.  It plays a different animal sound based on the color detected by the color sensor.  The goal here was to teach advanced program flow by doing something fun.  We discussed how this program might be used for the challenge.  The girls came up with using it to detect objects and to determine which program to run.  By doing the challenge, they reinforced their understanding of the loop and switch blocks.  To figure out the logic, the girls referred to our Program Logic Poster.

Here is the first version the Master DJ program; it has evolved to exit on the color sensor detecting white – and makes me want to invest in earplugs.






EV3 vs NXT: Which one to use?

Disclaimer: I am a geek.  I love new technology and always want the latest and greatest,  That being said, if you are trying to decide between sticking with the NXT or diving in with the EV3, I would recommend the EV3.  The NXT is great and using it in competition will not be a disadvantage.

This year, the plan was for the Capital Girls to use the EV3 that was provided by our PTA, with the understanding I will train coaches next year.   The Code Crackers were going to use their NXT, since it’s their last year of FLL.  After playing with the EV3, I wanted one for the Code Crackers to use.   Like I said, I am a proud geek.  Here is my rationale:

Software Learning Curve

The software interface is very similar, reducing the learning curve.   The concept is the same – drag blocks from a palette onto the canvas and set the properties. The big advantage about the EV3 Software is the properties are inline with the block.  I also like how connectors work and the fact you see the what is in what port.  Keep in mind, you can use the EV3 software with a NXT brick.

 4 Motors

The NXT has three motor ports and comes with three motors.  If you use two motors for the wheels, you have to use gears to distribute power.  The EV3 comes with four motor ports, and teams are allowed to use four motors in the Nature’s Fury Challenge.  The EV3 only comes with 3 motors, but you can use NXT motors or order a fourth.  I thought that they would limit everyone to three motors this year, as the ability to use a fourth is an advantage.  That said, be sure to read the challenge rules for yourself; don’t take my word for it.

Chassis and Motor Attachment Interface

MotorInterface The new chassis and motor attachment interface are very strong, which should make a for more consistent robot.  A robot that will go straight.



Program Debugging

When connected to the robot via blue tooth, you visually see the program run.  This will be great for guiding and debugging.









EV3 vs. NXT: Hardware

I love what Lego did with the EV3.   The new brick power and functionality is fantastic, but I think the addition of the new elements and attachment interfaces will make for stronger, more consistent robots.  Yes, I used the words ‘consistent’ and ‘robot’ in the same sentence.

New Chassis Pieces


Lego added two chassis pieces to the the set.  This may not seem like a big deal until you join them with the new motor.  The connection is very strong, which should create a robot that goes straighter and is more consistent.  I know, I used a bad robot word.


znapNew Treads

Lego did add a new tread system to the EV3. Treads look cool and every boy wants to use them, but in my experience, only use treads for FLL if you don’t want a robot to go straight.   They are great for climbing but the consistency trade off is not worth the gain.  Neither of my teams nor I have tried out the new treads yet.  The new system may work better, but I still have nightmares about treads.



Not in EV3 Kit

Motorcycle Wheel

wheelI want the old wheels back.  I am not a fan of the new fat tires.  I have not tested or seen my teams test them but the bounce screams inconsistency.  I am sure there is a reason for this fat tire design, I just don’t see it.  Also, the bigger the wheels the faster the robot.  There are no big wheels.  To satisfy my team’s big wheel addiction, we added the Lego Motorcycle wheels to our kits.


EV3 Interface

EV3 vs NXT: Software

The EV3 software is very much like the NXT.  My Code Crackers team wrote a line detection program with recovery logic on the EV3 in under 10 minutes.  This was their first time using the program.  The location of the tools pallet is different – on the NXT it is on the left and in the EV3 it is at the bottom.  Same concept, though, drag blocks to the canvas and set properties.

Inline Properties

My favorite change is inline properties, at least that is what I call it.  Properties are visible and editable on the block – no more clicking a block to modify properties in the properties window.  This makes coding faster and the code more readable.  Below are examples of the line detection program in both the NXT and EV3 software.  The program looks for a black line.  If the black line is not detected after .94 rotations, it exits the loop.  The program uses a reset motor block, loop with logic exit condition, rotation sensor, light sensor and logic block with an “Or” condition.


NXT Line Detection with Recovery Logic SampleLineDetection_ev3EV3 Line Detection with Recovery Logic Sample

Data Wires


The data wire interface is much simpler and cleaner.  The shapes, half circles and triangles, indicate what can be connected.  This is a big improvement.


Source: EV3 Help Content

Port View

EV3PortViewerWhat port is the color sensor?   In the EV3 Mindstorm software, you have access to a port viewer to see what is connected to each port.  I love this feature, no more guessing or cable tracing.

Flow Indicator

This is really cool – when connected to the brick, you visually see the program flow.   This makes debugging so much easier and fun.


EV3 Software on NXT

We also tested the EV3 software with an NXT brick.  It works.  Even if your team is not using the EV3, you may want to utilize the new software just for the inline properties.


Robot Design Kick-off

Our team looks at robot building as a collaborative team building activity.  Before any pieces are connected, the team goes through a robot planning meeting using the Robot Design of Team Notebook. This allows the entire team to collaborate on a design and for a few to build it prior to the challenge release.  Everyone feels they own the robot, even if they did not build it.  This process takes about an hour but saves so much time later on. It is also a great team building activity and forces the team to document robot design.  We do this mid August, before the challenge is released but when the challenge is assembled.  The key here is to get a good base robot base and understand that it will be modified once the challenge is released.

Below are the questions the team uses for planning.  Part of the process is explaining and documenting why they selected a design.  In November, they will not remember why they made a decision but they can refer to their notebook.   If someone misses a meeting, they can refer to teammates notebook to catch up.

  1. What type of robot do you want to build?
  2. What type of wheels?
  3. How do you want to support the wheels?
  4. Will you use sensors for navigation?
  5. What sensors do you want to use?
  6. Will you use a starter jig or line following?
  7. How will you attach attachments?
  8. How will you power attachments?
  9. Can you use gears?
  10. What are the goals for the robot?  (e.g. consistent, fast, strong)

icon_pdfDownload the Robot Design Section of the Notebook.

Organizing 541 (Core Set) + 853 (Expansion Set) Legos

Plano 1374 4-By Rack System 3750 Size Tackle Box

Plano 1374 4-By Rack System 3750 Size Tackle Box

How exciting! The EV3 Core and Expansion Sets you have been waiting on for months just arrived.  Now that the stress of wondering if it will arrive in time for the Nature’s Fury challenge has been lifted, you have to start organizing and learning it.  There are several options for getting your kits organized:  you can use the Lego bins that shipped with the set, throw it all in box, hire a professional organizer or exploit a tackle box.

I love the Lego bins that ship with the kit, I use them all the time to sort stuff, but I find they are not the best solution for our kits.  The pieces get mixed up easy, and theirs doesn’t lend itself to the level of organization I prefer.  My solution?  A tackle box.  To be specific, I used a Plano 1374 4-By Rack System 3750 Size Tackle Box with the addition of a 3750 Stowaway box that fits in the top section, along with the wheels and cables.

Plano1374OpenI like the tackle box over other options because it is very portable and durable and, most importantly, it keeps pieces organized.  I would also recommend looking at solutions from Robotics Learning.  I  used their kit for the NXT, and it worked great.  Their labeling is great, and I’m eager to see what they offer for the EV3.


Duct Tape Team Building Games

It is true, there is no limited to what you can do with duct tape.  Given all the uses for duct tape, why not use it for core values.  Easy to carry for when you need a quick core values challenge.

The challenge pictured is “Consensus Loop” and is being performed by the Code Crackers.  I also did this with the Capital Girls.  Both teams loved it.  The objective: in 5 minutes, determine which of the duct tape loops is holding the other four without touching the loops. Setup is easy, start with a strip of duct tape, about 30 inches long.  Fold in half crosswise to make a long narrow strip, and connect the ends to form a loop.  You do this four more times and when you make the fifth circle, connect all the circles. Throw the bundle of loops on the floor or table to start.  When the team has an answer, they pick up the selected loop to see if they got it right.  It is harder than it looks.

This game develops problem solving, conflict management and compromise.

To find more team duct tape building games, check out Tom Heck’s book Duct Tape Teambuilding Games — 50 Fun Activities to Help Your Team Stick Together.