Troubleshooting NXT-G programs can be a little challenging. There aren’t any traditional debugging tools built into the environment. Here are three ways you can emulate common troubleshooting techniques when your program isn’t working the way you expected.

Watch variables – You probably know you can monitor a sensor in the bottom left corner of the screen. If you keep the NXT connected to the computer, you’ll see the value of the highlighted sensor block in real time. But what if you can’t keep the robot tethered or you’re trying to monitor another value? Put it on screen! Use the Number To Text Block to send data to input B of the Text Block. Use A to name the variable and C to pad the output with blank spaces. Send each value to a different line using the Display Block. If you drop this all into a MyBlock, you’ll have a simple routine to watch a variable without cluttering up your program.
Set breakpoints – Breakpoints are really useful because they halt the program at a certain spot so you can inspect the state of your robot. When I’m trying to isolate a program bug, I use the Stop Block and just move it down the line to test each step of the program. This works great when you’re trying to navigate and aren’t sure why your robot is going off course.
Set alerts – If I’m not sure which branch my program is using in a switch, I’ll add audio cues to my program for each branch. For instance, I wrote a program to read color codes and perform different actions depending on which color it identified using the color sensor. To confirm the color sensor was seeing the colors accurately, I made each value in my switch say the color name out loud.

Use these methods alone or together to quickly get to the root when your programs are misbehaving. You’ll save a lot of guesswork by using these three simple techniques to pinpoint problems and isolate failures.

Forget about STEM! We’ve been all about STEAM (Science, Technology, Engineering, Arts, and Math) with our robotic zoo! Over the past six weeks, the kids at the North Tampa Robotics Club, South Tampa Robotics Club, and Learning Gate Community School have been hard at working building a robotic zoo to exhibit at the Tampa Bay Mini Maker Faire. This past week, 26 of us from these programs exhibited six different habitats featuring ten different student built robots. The effort took over 200 hours of effort to build the robots, program their behaviors, decorate them and build their habitats.

African Savanna

In this tropical grassland, massive herds of zebras and giraffes roam freely. Here, a couple of individuals pause briefly for our enjoyment.

The giraffe uses its long neck and towering body to reach the succulent leaves high up in the tree while the zebra, an animal rarely domesticated pauses momentarily and responds to being petted.

Materials
The habitat is constructed of paper mâché, painted and decorated with an assortment of craft and hobby materials. The animals use LEGO NXT Mindstorms for motion and sensing. The zebra’s coat was knitted by Mrs. Edwards.

Central American Jungle

Deep in the jungles of Central America, the plants attack and the animals do their best avoid predators by blending in with the background.

The Venus Fly Trap attracts insects and can sense the presence of a meal within its grasp. It feeds by closing on the helpless morsel trapping it and digesting it. Meanwhile, the chameleon’s unique ability to camouflage itself by changing colors to match its environment is simulated here by detecting colors in front of its sensor and then relaying the color data via XBee to an Arduino which has been programmed to gradually transition the skin to the newly detected color. An array of 15 RGB LEDs provide the lighting for the chameleon’s skin.

Materials
The habitat is constructed primarily of natural materials. The motion and sensors for both animals are LEGO NXT Robotics. In addition, the chameleon uses a third party NXTBee communications device and interfaces in real time with an Arduino using an Xbee shield. The LED array was built directly onto a plastic needlepoint canvas and wrapped around the torso. The head and tail are modeling dough.

The Jurassic Era

Witness the ferocious struggle for supremacy between these giant beasts as the T-Rex, stegosaurus, and crocodilian engage in a three way battle to dominate the Jurassic Period! Which will reign supreme? Each animal has its own special mode of attack.

Materials
The habitat is cloth over cardboard. Each animal is powered by a LEGO NXT robot with attacks programmed to occur at random intervals.

Dragon’s Realm

Prepare yourself to enter the realm of fantasy. Perched high atop a mist shrouded mountain, the dragon lays in wait for intruders. Venture to close and risk the wrath of this magnificent creature!

Materials
The mountain habitat was built using a five gallon paint can, crumpled newspaper and an old sheet to obtain the shape. The surface was then covered in paper mâché and painted with a black primer layer followed by a stone textured spray paint. Finally, the stone texture was dusted with more black to give the finish a bit of variety.

The dragon’s skeleton is constructed from LEGO TECHNIC elements and powered by LEGO NXT. The wings beat using synchronized cams that translate the motor rotation into an up and down motion. The dragon was originally finished with a hologram gift bag cut to size and LEGO Bionicle parts. The fire is simulated using a 12V fan connected directly to the NXT brain with a custom cable harness. The fan blows metallic streamers to represent flame.

The Minifig Garden

This minifig scale garden features a Hexbug maze. Can you see the word LEGO on the maze? Traversing this maze is a small collection of Hexbug Nanos. As they reach the end, a gantry robot detects the presence of the winner and transports it back to the start.

The audience was invited to add decorations to the garden from the available materials.

Materials
The entire garden is made of classic LEGO town elements with a smattering of castle and pirate bits for drama and interest.

The gantry robot is controlled by a LEGO NXT robot. Using the color sensor, it watches the capture tube for anything non-yellow to cross the sensor’s view. Once it sees the Hexbug, the capture tube is lifted and the robot traverses the gantry to deposit the bug back at the start of the maze. Three layers of specialized LEGO bricks provide a rigid track to span the 48 inch distance between the support columns and support the weight of the robot.

Prairie Dogs

This clever automaton is powered by a single LEGO NXT to drive both the hawk and the prairie dogs. The prairie dogs carefully scan their surroundings alert for predators who might threaten their colony. If a predator is sighted, they go into high alert to make the neighboring families aware of the looming threat.

Materials and construction techniques
The prairie is paper mâché over cardboard. The hawk’s perch is a five gallon paint can for a tree trunk covered with material and finished with a canopy of faux leaves.

The hawk’s skeleton is made from LEGO TECHNIC elements and its surface is finished with feathers. The wings are controlled by a single motor and synchronized using a pair of cams to beat in unison.

The prairie dogs are clay and sit upon a clever arrangement of cams and gears to achieve the complex motion. The cams are driven by a single NXT motor and are arranged to vary the speed and amount of movement for each prairie dog. You’ll notice that several of the dogs rotate as they emerge from their burrows. The rotation is accomplished using a combination of rack and bevel gears to create a complex motion from the motor’s rotation. The alert is triggered by an ultrasonic sensor mounted in the hawk (they look like eyes).

Tramway

Ride our electric tram as it winds its way through the zoo. This motorized train is in its third iteration in just two short months! At each end of the track, a switch reverses the current and sends the train back towards the far side of the exhibit.

Materials
The tramway is constructed exclusively with LEGO using vintage 9V battery boxes and motors.

NEWS HIGHLIGHTS:

• The LEGO® MINDSTORMS® Education EV3 platform is the third generation of LEGO Education robotics technology designed for classroom use. It is a full teaching solution developed with educators to actively engage students in a number of key curriculum areas such as computer science, science, technology, engineering, and math correlated to national standards.
• The EV3 platform includes customizable curriculum and digital workbooks; a hardware platform based on real-world robotics technology for engaging, hands-on activities; an intuitive software platform consisting of both programming and data-logging interface including 48 step-by-step tutorials; and extensive professional development courses.
• The EV3 platform includes customizable curriculum and digital workbooks; a hardware platform based on real-world robotics technology for engaging, hands-on activities; an intuitive software platform consisting of both programming and data-logging interface including 48 step-by-step tutorials; and extensive professional development courses.
• The LEGO MINDSTORMS Education EV3 platform is backward compatible with the previous MINDSTORMS Education NXT platform, ensuring that existing sensors, motors, and building elements can be reused. It is also possible to program NXT using the new EV3 software.

NEWS RELEASE – January 7, 2013 – Today, LEGO® Education announced the LEGO MINDSTORMS® Education EV3 platform, the next generation of robotics for the classroom, continuing 15 years of MINDSTORMS robotics technology for education. The EV3 platform was created based on feedback from more than 800 educators worldwide and provides relevant robotics curriculum and technology for teaching computer science, science, technology, engineering, and math through a hands-on experience with sensors, motors, programming, and the programmable EV3 Brick. Students can now build and program a fully functioning robot in a single 45-minute class period.

The platform includes customizable curriculum that is digitally delivered and installs directly into the LEGO Education MINDSTORMS programming software lobby. The built-in digital workbook can be used by students to capture their work as they progress through the lessons, making it easy for the teacher to follow students’ progress and assess their work.

The EV3 platform includes Design Engineering Projects, a curriculum package with 30 hours of classroom instruction. The structure of the activities in the Design Engineering Projects curriculum follows the engineering design process used by scientists and engineers in many industries. Using videos of real-world robots as inspiration, the students are given a design brief that challenges them to develop, design, and share their solution. Throughout the process, students learn through combining and applying science, technology, and math disciplinary skills as they engineer their design solution. This structure is designed to help students develop the creative-thinking, problem-solving, teamwork, and communication skills required for success in school and beyond.

The LEGO MINDSTORMS Education EV3 Core Set comes with the EV3 Brick, rechargeable battery, sensors, motors, large brick selection, a new ball wheel, and building instructions. The intuitive software platform for EV3 is based on National Instruments LabVIEW™ graphical programming software, the same technology that powers some of the greatest innovations on the planet, and includes new data-logging capabilities that allow students to collect, graph, and calculate their data. Also available is the LEGO MINDSTORMS Education EV3 Expansion Set, which enables students to build larger-scale, more complex robots. For easy classroom management, both the base education set and the expansion set have storage bins and sorting trays.

LEGO MINDSTORMS Education EV3 is now available for preorder and will ship in the fall semester of 2013.

Our North Tampa Robotics club just finished our SUMO competition last night. Eight teams competed for glory in a heated competition. I want to recognize all of the teams who participated – they all worked really hard building and refining their robots!

Armored Panzer Division – Bennett and Kevin
Tank Masters – Amilio and Alex
The Twisting Tornadoes – Trevor and Manat
Mbotm Bots – Will and Lleyton
Savage Sadie
Mad Marcy
Raging Ross
Hulkbots – Logan

Congratulations to our tournament champions!

Gold – Mbotm bots (Will and Lleyton)
Silver – Armored Panzer Division (Bennett and Kevin)
Bronze – Mad Marcy
Bronze – Tank Masters (Amelio and Alex)

I would like to recognize Greg Call who hosted a SUMO competition earlier this year in Stuart, FL. I wrote my own rule book using his rules as a starting point.

Robots were limited in weight to 1 KG and by size to 9 inches square with no height restriction. All robots were constructed using only LEGO parts with one intelligent brick per robot.

The basic format of the tournament is patterned after fencing tournaments with an initial pool round followed by a single elimination bracket. For the pools, competitors compete against every member of their pool. Each round is comprised of three encounters with two points possible per encounter (2 for an outright win and 1 each in the case of a tie). This gives six possible points per round.

Once the pool results are tallied, the bracket is seeded based on three criteria.

1. Average points per round calculated as a competitors total points divided by the number of rounds they participated in. If all pools are of equal size, you can just use total points.
2. The first tie breaker is the average time to win. Calculate this by adding up time it took a bot to win (ignore losing encounters) and divide by the number of encounters won. Lower times are better
3. The final tie breaker is based on robot weight. This only came into play for bots without any wins but did come into play. Lighter robots are better.

Once the competitors were seeded into the elimination bracket, we had a quick elimination round with the final four competitors all receiving awards.

I was so busy officiating, I never go to take any pictures. Please comment with your pics and I’ll get them online!

I did capture some photos of the work in progress over the last few weeks. Enjoy!

I received the Senior Solutions FLL field setup kit in the mail last week and built it for my boot camp this week! Most of the models sport very cool mechanisms. I’m thinking I’ll have the students build a second set so they can get a gear lesson or two out of the experience. Positioning for most of the models on the mat is pretty self-evident thanks to the marking on the mat. I haven’t a clue how to position the medicine units and there are a few variations on how to position the quilts but mostly it’s quite straitforward.

I find a few of the missions to be quite curious. Every year, the robot challenge has featured either a competitive or a cooperative mission in the middle of the field. This year, that mission is a ball launching mechanism that send the large plastic balls onto the OTHER team’s mat. I’ll be very interested to see how that will be scored. It definitely adds an element of randomness for teams who may have to navigate around or through obstacles that they can’t predict. It could be a real wild card for teams who don’t have the benefit of a double table to practice with.

You can see the overall layout of the field here. It’s not nearly as busy as the last couple of years but the spaces to navigate are still pretty tight. You may notice that base is smaller than usual. It is rectangular in shape rather than square.

The pet help mission has a really nice mechanism for translating a pushing motion 90 degrees. When you push the bumper on the east side, it propels the service dog towards the base area. You can see the woodworking shop (table and chair). The instructions don’t show the chair fully assembled but the back portion is placed as indicated on the mat. The quilts may or may not be arranged properly but the mat does show a total of five areas that require dual lock and are exactly the correct size. This would leave three quilts unencumbered. Just to the right of the quilts, you can see one of the hearing/seeing test. Initial position – flag up or down? You decide!

Yay! Another bridge! The west side has steps, the east side has a ramp. The middle wobbles and isn’t fastened directly to the mat. I’m not sure what kind of Mayhem is planned for this one. Perhaps an ending condition for the robot’s location? Just next to the ramp is a stove. The level flips the stovetop and turns the burners off. To the far north (left side) is the ball game. When you push the wheel attached to a lever, it launches balls one at a time into the opposite field. Closer to the bottom left is the “Similarity” model. Based strictly on the name, I’m predicting that this is a cooperative mission. Finally, on the left and right sides, you can see orange and green structures with rings. We all know what the rings mean! However, these are not dual locked and there is no indication where these will start. There are a total of three orange and one green “medicines.” They could start in base. I simply placed them randomly around the field.

Lastly, you can see the placement for the fifth quilt. That is the only one with a color hint but placement of the quilt on the square doesn’t quite make the color fit the space. The really tall structure is called “shopping” and it has two grocery? items. One is visible at the top while the other is hidden and rests on a bottom platform. Just to the left is the other half of the hearing/seeing test mission. Behind the structure is a bowling lane with six pins. Anyone else thinking penalty objects? To the right are two pieces of exercise equipment. The one in the foreground is a cardio machine. Spinning the wheel causes an indicator on the south side to move. It looks like it takes 12 full rotations of the wheel to move the indicator all the way from green to red (or reverse). The machine in the back is a press. Once you raise the weight, it remains elevated. Both of these machines use complext gear trains to manipulate the object. In six years of coaching FLL, I have seen very few teams use gears in the robots and attachments. Hopefully, this will spur some creativity in that area.

Not specifically mentioned are two gardens and the yellow bowling ball that are currently sitting in base.

It looks like we’re going to have a fun season! I can’t wait to see the actual rules on August 28th!

This Friday, June 8th, I will be closing registration for two weeks of robotics camp in June. As with all of our camps, you can register online or print and mail the registration forms.

Current status for our June camps:
June 11th -15th (South Tampa – PM Only). Camp is confirmed. We have a few open spots and I will accept registrations through June 10th.
June 18th – 22nd (Riverview @ Kid’s Community College). Both the morning and afternoon sessions are still below the minimum number of registrations. I will notify all registered campers on Saturday, June 9th if the camp is cancelled.
June 25th – 29th (North Tampa @ Messiah Lutheran Church). Both the morning and afternoon sessions are still below the minimum number of registrations. I will notify all registered campers on Saturday, June 9th if the camp is cancelled.

All July camps (Lutz Prep and Trinity) have plenty of campers and are confirmed.

Registrations for the August boot camps are light. I will post a status update for these camps once they are confirmed.

If you’ve registered for one of our camps and are considering a second camp, don’t forget we offer a $20 discount for siblings and for each additional camp session.

If you are on the fence and considering the camps on June 18th and June 25th, now is the time to commit. If we are able to confirm the camps, I will extend the registration deadline to allow additional campers to enroll. If the camp is canceled, it will be permanently removed from the schedule. In the event we cancel any camps, paid campers will have the opportunity to switch to another session or receive a full refund for their fees.

Don’t forget, robotic summer camp registration for all weeks and locations is still open! We have camps available in North Tampa, Riverview, Lutz, South Tampa, and Trinity. Dates, locations, and all the details are on our camp page.

For our Monday club at Kid’s Community College, we decided to take a break from the FLL mats and work on something a little more open ended.

I’m sure most everyone is familiar with the crazy TV Show Wipeout. We are going to build a few sections of their brutally fun obstacle course using the NXT motors and sensors. The build will be approximately at Minifig scale.

Since the KCC Robotics Club is going to take a break for the summer, I thought it best to pick something fun that we could accomplish in just a few weeks. For this build, I’m busting out lots of interesting bits for the kids to build with. I think the tricky parts will challenge them nicely. For instance, the Sweeper will require building two concentric sections which will need to rotate in opposite directions. The punching wall will need to at least appear to be randomly pushing LEGO bricks out to knock “contestants” from the ledge.

I’m not sure if we’ll have time to build the Wipe Out Zone, but it will have some interesting challenges as well. Perhaps I’ll save it for summer camp!