FLL 2009/2010

First Lego League holds a competition yearly, with the same question being used for the whole world. What I love about the FLL is that, everyone competes using the same questions, same play field, as well as same lego sets. Where all remains the same, only their creativity/ingenuity of each team to solve the problem will make them the winning team!

You can view the full FLL rules for FLL Smart Move 2009/2010 here.

For a quick summary of what you will expect from the FLL Smart Move 2009/2010, you can view the video below

I suck at writing blog.
But still, here's my point of view on the robots.

Small and agile with risks are what our competitors did during the K. Terengganu NRC.
They used the aim and shoot method.
This method basically is to make the robot move straight and grab ( other methods also apply) the object and put it to the destination.
They risk:

1. The position of the robot at start point must be EXACTLY where they have programmed.
2. Battery voltage must be EXACTLY the same as what they have programmed using.
   
3. Luck. No luck = GG
4. They must programmed it correctly in a sense that the programming must be accurate by the millimeter. And that's just too back-breaking for us?
5. Even the condition of the mat will AFFECT the performance AKA determine their fate.
   

THE SLIGHTEST MISCALCULATION, MISTAKES, EVEN BY A MM, WILL RESULT IN FAILURE.




But if, and if, they are:

1. Lucky
2. Able to program well
3. Makes no mistake.

They get lots of points as their robot is fast.


Next, is what we did.

Use Light Sensors to move with the black lines on the mat.

This method is:

1. More accurate.
2. May auto-recover.
3. Minimises human-error as the robot will move itself without requiring us to aim the robot.
4. It's now a fully-automated robot. No a car that picks up objects blindly.
   

Nothing is perfect. Same goes with this method.

It's :

1. SLOWER if compared with aim and shoot method. But if it's programmed well it may go faster ? ( unconfirmed, no chance for us to see others use this method )

Method of getting object.

This is gives us a headache till the very end of the competition.
We thought of all kinds of methods. Some fail. Some shines.
At last, we decided to go with the box method.
The robot's arm is a square that extends out of the robot.

The arm

We got frustrated thinking of other methods that we go ahead with a very straight forward box that just swoops in the object.

Well, this method brings a lot of problem.
Especially with the rubber object.
Rubber + mat = Friction and loads of it.

With the robot pulling the object, it's like telling it a mammoth task for the robot. It squeaks, jerks and even jumped over the object with the object still stationary.


There's also the grab method, grab-n-lift method, scoop method and so on.




It's late now. gtg. So, anything missing? Wrong? Bullshits? Please dump it in the comments.
And hopefully, I'll make up to it in my next post.




P.S. This is my first time writing and posting a blog post.

Point of View: Robot Massacre

Hello world ! This is my first post. Thanks to Eric for the invitation.
To make sure our robot will keep moving forward, I came up with these few questions and opinions that I believe is essential for our future robot construction.

First of all, the size of the robot. Our previous robot moves slow and steady although a bit bulky.
The mass of our previous robot is a pro and also a con. The weight is important to decide because it will eventually affect our turning, movements, power consumptions and of course the type/number of wheels. How can we give a balance "diet" for our future robot from being fat and slow? We can build it small and compact, mild and light or just with simple mechanisms.

I believe the robot should be small, simple and not-too-light.
Small, it is easier to build and does not interfere with the tracks or turnings.
Simple, just in case anything screws up, rebuilding it would be easier.
Not too light, a little bit of weight is recommended to prevent the robot from slipping, jerking and possibly gets off track.

Another thing to take note of is the sensors. It is always light sensors. Our previous robot is causing a lot of inaccuracy and failures on turning.
The obvious reason is the distance between the sensors and the wheels. The sensors shouldn't be too far from the wheels nor too close.
Our future robot should have a close enough distance from the wheels. So when the robot stops, the wheels are in the exact location as we want.

Arm mechanism. So called the pain in the ass.
Is there an arm design that could pick up almost every shape and sizes ?

Is grab-n-lift a good option ?
Do we really need an arm (guess so) ?

The following is the battery. Which battery should we use on competition day, rechargeable or new AA batteries? It would be best if we get some sponsorship from the school for batteries. Program using rechargeable then optimize it to a higher voltage, sounds good ? I believe the old design is a power hogging machine, therefore the new design must be small. It failed on the design and programming. Better design is a must. Until now, I'm still wondering how did we won third prize in the competition with this rotund golem.

Next, the wheels. Should we consider more than 2 wheels ? Do we need small wheels or big wheels? I think we are better off with big wheels (previous wheels).
The small wheels isn't giving much "grip" from what i see, and it may slip if we use a faster speed, it's just too light. The wheels are depending on the size of our robot. It's not like we put tiny wheels on a giant machine, that would be LOL !
Besides that, if possible, we're going for max power and max velocity. We never know what would happen next.

My views may be a little bit of obscure and ridiculous, I think you get the idea. Well, it's just my point of view.

Tell us what do you think about a winning robot.

Cheers.
-CH-

3D modelling using Solidworks

I have been relearning Solidworks (a 3D CAD software widely used by engineers & designers) for a while and decided to do some simple modelling on my own after going through some of the tutorials. So i just picked the Technic studless straight beams as my subject due to its simplicity & my skill level :p

In engineering, just like in real life, there are many ways to solve a given problem and the rule of thumb is always to solve it using the simplest method. I completed the first 3M studless straight beam using 7 steps (or 7 features),

But i thought i used too many steps to complete the model, so i made another attempt to remodel the beam using different methods and this time around it only uses 3 steps to complete the model.

Satisfied, i continued to model the rest of the straight beams of varying lengths including 5m, 7m, 9m, 11m, 13m, and 15m & made a screen shot of all the different beams lined up together,



Overall, i had a fun experience using Solidworks to model the Technic beams. I understand there are a lot of LEGO CAD softwares out there that would satisfy most Mindstorms & Technic fans, but for the few who find them too limiting in features, eg designing your own custom parts, performing some stress analysis, or some motion analysis, then you should give Solidworks a try ! (provided money is not an issue for you :p)

Quick engage/disengage mechanism for gear trains

Due to the challenging design of this year's Robot Energizing objects, many teams have come up with pretty interesting designs to carry the resources (i.e coal, bio-fuel, and esp. solar). One of the biggest challenge the teams face is to design some mechanism which can grab and lift the object by using only 1 motor as the other 2 have been used up for navigation.

So, some of the more successful teams have employed the grab & lift mechanism similar to the one shown below,

This is a brilliant solution for grabbing & lifting the Solar rescource off the ground, but there's a slight drawback to this design when the gear reduction ratio is too big - you need to turn the motor many rotations to reset it to the original position everytime the robot misses. So one the solution the teams come up with is to attach another knob/wheel along the driving axle for manual reset. However, this still takes up an awful amount of time, especially if your robot miss more than once :S

Recently i came across a very interesting mechanism that can engage/disengage a gear train with relative ease and i thought it would be an useful add-on to the grab & lift mechanism for quick engage/disengage in the event the robot misses the object.

I have uploaded the videos showing how the quick engage/disengage mechanism work along with the grab & lift mechanism without the quick engage/disengage mechanism for comparison.

Grab & lift with quick engage/disengage

Grab & lift without quick engage/disengage

This mechanism can even be applied to grabbers which uses wormscrews, which can save even more time on resetting the grabber.

Almost Famous - NRC 2009 Newspaper Article

I have been in Kuala Terengganu for less than 6 months, and I am already making a scene. Creating too much publicity is NOT a good thing :)

We had a little tiny article printed on the Sin Chiew 18 July 2009 about our recent win in the NRC 2009.

Since I cant read chinese, I can't give you a summary on what it says, but most probably only good things :)

Those who didn't see the article in their Sin Chiew is because it is printed in their equivalent of Metro section (The Star), where it only talks about local events in Kelantan, KT and Kuantan (East Coast).

Lego Technics Quad Bike 8262

Isn't the Quad Bike just sexy? I must admit, most of the 2009 Lego Technic models are just awesome. In fact, I am eyeing the Technic Go Kart too! Not forgetting all the Star War Series, that I have already spent too much collecting.

I must admit, but this is the second Technic set that I have built. It is NOT that I don't own any other Technic sets, but all of is still Brand New in Box. I have the Lego Bulldozer 8275, but just haven't gone around to building it. I am sure it is an awesome set, with all the PF Motors!!

When I first opened the box to the Quad Bike, I realised that there is so little pieces in there. With all the packets on the table, I was wondering whether have they left any parts out? Most of the weight of the items are in the rubber wheels :p

After pouring all the parts out on the table, I realised that it is filled with many many small parts. After a quick flip through of the intruction booklet, I realised that there is alot of little details (and little parts) used to make the quad bike.

I spent closed to 2 hours building the Quad Bike. I really like the front suspension that the Quad Bike have. The design is great, and I hope to incorporate it in my future NXT designs. The only problem is that, the pieces and absorber piece is unique to this set, and NOT included in any standard NXT Set :(

It has an alternate building instruction to build a Buggy. I will be building it soon, and will definately post the pictures of that soon.

NRC 2009 - 3rd Place Kuala Terengganu State

Here is a photo of the kids from SMK Chung Hwa Wei Sin with the 3rd Price win at the NRC 2009 Kuala Terengganu State level.

Congratulations to them on work well done of getting 3rd place. It is their first year with the NXT and coaching them from ground up is no easy task, not to mentioned with their busy schedules, they only had about a month to come up with their robot design and program for it.

Going against students who have got NXT experience, not to mentioned that they had already completed a similar NRC 2008 question is no easy task. Luckily with the long hours put in, they manage to obtain 3rd Place.

The kids are (from left to right)

• Cedric
  
• Koong (Chief Programmer)
  
• Chen Hui (Chief Builder)
• Eric Tan (Coach)

I expect nothing less from them next year, only First place would be acceptable!

I will be posting more on my NRC experience in the future post, as well as the design concept of our NRC 2009 robot, as well as mistakes that we had made.

Lego City Coat Rack

Look what we have here. It is a very similar concept to what was posted earlier. Check photo below, and link to posts.

Automatic Bucket Filler

It's been a while since my last NXT project, and since i got a week off for CNY so why not do some home improvement to make the home a better place to live in, right ?

In the house i live in, "someone" just have a strange habit where they like to leave the tap dripping all the time and i can never understand the logic or the rationale behind it. So i decided to probe deeper and find out the answer - "Oh, i just leave it dripping all the time so it will fill up the bucket automatically" was the reply i got :S

The problem was the bucket overflows all the time that is a tremendous waste of H2O...Hence, i came up with the Automatic Bucket Filler.

This system consists of one motor and one touch sensor. When the water level is low, the ball drops to a lower level and the touch sensor is released, signalling the NXT to rotate the motor to turn on the tap; when the water level is high, the ball raises due to buoyancy and presses the touch sensor, signalling the NXT to turn off the tap.

The motor turns the tap.

The ball rises and lowers depending on the level of the water, and when the level is high enough the ball will press on the touch sensor to signal the NXT to turn off the tap.

Ok, i know you can't wait to ask me how much can i save with this system and what's the ROI ? After doing some simple calculations,

Annual savings on water bill : RM 5

Cost of Mindstorms NXT      : RM 1400

Return on investment (ROI): RM 1400/RM 5 = 280 years !

Hey, just 280 years only mah, not bad wat... after 280 years can start saving RM 5 every year oredi, so chun !

Lego USB Drive - Thinnest Ever!

I am sorry if this is a little off topic. I made a few over the weekend. I reckon you can't get smaller than this for a USB Flash drive. If you guys would like one, drop me a message. The best thing is that, it is Vista ReadyBoost compatible!




The LEGO USB Drive featured is almost completed. I have not mounted a small ring that would allow the LEGO USB Drive to be mounted either on a Keychain or a Lanyard (perfect for showing off!)

Currently I have 6 colours available

I would like to apologise for my sub-standard photos. Photos would be re-taken with better lighting condition and using a tripod to ensure that the photos are sharp as it can be!

You can check out more details here.

Simple Skid-Steer 4WD with Power Functions

Over the weekend i just wanted to build something out of the new power functions elements from the 8275 Bulldozer - hence i came up with this simple remote-controlled model with no programming but pure fun.

This is a simple skid-steer 4WD using power functions elements including 2 XL motors, 1 battery box, 1 receiver and it can be built in under 5 minutes.

Each side of the wheels is controlled by 1 XL motor and steering is accomplished by turning both motors in opposite directions, just like the way you drive a tank...

The car tends to jerk a lot while turning due to the nature of skid-steer architecture but i had a lot of fun with it, especially with the reaction i get from my sister's dog when i drive this thing around right in front of her ^_^

NXC Tutorial by Danny Benedettelli

If you have downloaded the NXT Tutorial by, please download it here.

Don't worry about the NXC guide. You'll only need the Guide if you are doing more advance programmes. Until then, just use the NXT Tutorial and follow it step by step.

I have gone through the tutorial and find it pretty complete. It goes through most of the basic features that are available in the NXT-G language.

I will start to write some more advance program and post them back here.

I will assume that you have already complete the NXC Tutorial and fully understand the basic NXC features as well as the C programming language.

Alternative Software for your NXT Mindstorms - NBC/NXC

Today I will be writting a short article on how to install and use alternative software. The first one I will be looking at is the NBC/NQC/NXC. You can read more about these 3 alternative software here.

The beauty about this about the language is that, you could use the standard firmware, without upgrading your NXT Firmware. Why it is great is that you could use the more advance, while having the option to use back the NXT-G software, if you wish to do a quick test or demo without flashing your firmware back to the original one.

NBC (Nxt Byte Code) is actually a very low level coding. It is about an equivalent to assembly language. Basically you can't get lower than this!

NXC is (Not eXactly C) is a high-level C language. It is written above the NBC language.

I used NBC when it was first released and upgraded to NXC when it was introduced.

You'll need to download 2 software to get this running.

• Bricxcc -GUI Interface for the NBC Compiler
  
• NBC - NBC Compiler
  

Start by installing the Bricxcc (Bricx Command Centre) GUI interface. It is pretty straight forward.

Next please extract the NBC Compiler. Please remember the directory where the files have been extracted to.

You'll need to attach the NBC compiler so that you can access it from within the Bricxcc.Under the Edit menu, please seleect the Preference option.

Then select the little box with the "..." and include the path where you had extracted your NXC file.

Once you have done it, please compile the file "struct.nxc" which was included in the NBC compiler.

If you have done everything as I have explained, you should be able to compile the programme and run it.

Download the NXC Guide or NXC tutorial from this link.

I will have some tutorial on how to programme in NXC in my future post.  

Poor Man's Key Hanger

Leaving a bunch of keys all scattered around the table bothers me and I just decided to look for some key hangers to put the poor fellas where they belong. The problem was i always forget to buy them until i got fed up so I just put together a few pieces of LEGO Technic plus some good quality double-sided tape to create my own version of key hanger, and Viola !

Another advantage for using LEGO to make key hangers was saving money on buying new ones :P

Can you think of something else to do with your LEGO ? ( preferably something useful of course. )

8275 Bulldozer

I got this Bulldozer for a very reasonable price from ebay about two weeks ago and this monster took me around 10 hours in total to put together :S But it was definitely worth the effort as i enjoyed every minute of it :)

The first thing you will notice when you open up the box is the huge number of bags !! ( not to mention the 3 instruction booklets )

One of the main attraction of this model is the amount of Power Functions elements in the set. This set alone gives you :

• 1 remote control
• 1 battery box
• 2 receivers
• 2 XL motors
• 2 M motors

It took me about 4 hours to finish the first book and this is how it looks like,

The design and construction technique used in this model is very efficient, compact, and solid. The first book is all about building the chassis and the mechanism for the treads. 

The second book completes the rest of the functional mechanisms with all the electronics installed and it gives the bulldozer its exterior,

The final book adds the front blade and the ripper on the back to make the bulldozer complete.

In the pictures it may not look very big and let me assure this baby is HUGE ! Just to give you an idea of how big it is, i've put the bulldozer on top of my Mindstorms NXT box and took a picture.

The length of the bulldozer even exceeds the size of the box ! 

Overall, i was very satisfied and impressed with the bulldozer and i've already started thinking of using its treads for my next Mindstorms project....hehehe...

Kean's First Post

Hi guys, my name is Kean and im new to this blog, thanks to Eric's invitation :)

My background is in mechatronics engineering and currently working as a education trainer.

Since this is my first post i thought i'd post something interesting, something you wouldn't normally do with your NXT set in school. Allow me to present to you ( drums beating in the background.................) :

The NXT Bolter (Submachine gun)

I created this back in March. Inspired by Laurens Valk's 'Support Gunner' and other nxt guns, i decided to build a variation of my own. I wanted to build a gun which looks and feels like a real gun and hence - NXT Bolter.

It looks like a smg with an inverted magazine.I used 1 motor for loading the 'bullet' into the chamber, and another 2 motors for firing the 'bullet'. The firing is controlled by a touch sensor when the gunner pulls the trigger.

There are 2 modes to this gun: semi-auto and full-auto and the gunner selects the mode through the left and right button.The magazine can hold a maximum of 16 1x3 beams and the gun can be reloaded from the top of the magazine.

Picture

And the Winner is .... NRC 2008 Results

Congratulations to Victoria Institute for winning 1st and 2nd place...


But the real winner is the boys from SMK Taman Connaught, who came in third with 233 points. There were a dispute with the Head Judge as instructions given to them was mixed from 2 different judges.

Anyway, we all know that they are the TRUE winners, easily obtaining 265 points if there wasn't any issues with the judges.

Their team consist of

• Daniel Boey
• Jonathan Lee
• Calvin Boey

I would like to say that, extra credit have to be given to Daniel who did most of the building and programming as well as extensive testing.

There would more photograph and stories as well as LDD file for their winning robot.

We'll be going out for dinner to celebrate their win. Yes, these are the kids that I was teaching for the past 2 months.

Once again, Congratulation to Daniel, John and Calvin for their great job done!

You can read more about his robot as well as LDD and pictures here.
His strategy for the day was also explained here in the 2nd post.

NXTintro Workshop with Nicholas and Victor

It was another successful day for me. Two students attended my NXTintro Workshop on the 3 June 2008. Two brothers in fact. Their age was about 12 and 15 years old with zero experience with Lego or NXT mindstorms.

The day started with introduction to Lego Mindstorms. At first, they didn't know what to expect of our workshop. So I took out a previous Bot that I had built, and with my Bluetooth phone, I controlled it. Moved it around the table. They were like... WOW.... OOO....

After that demo, the kids seems more excited than me, and couldn't wait to get started with the Workshop.

We went through some basics before I allowed them to build a Robot each. Since it was their first day, instructions were given to them. Buidling with intructions is nothing difficult to do. Within 45 mins, their basic robot for the day was built. Next came the harder part of the Workshop. The NXT-G programming portion. With little or no experience in programming, teaching them would not be a simple task.

I gave them some very simple program to do. Mostly 2-3 blocks of programming. This is to get them used to the programming environment. After a few simple task, I gave them more complicated task to complete.

Before you know it, these kids were familiar and knew what they were doing. We continued the day by adding more components to the basic Bot as well as learn more advance programming methods.

Before the end of the day, I allowed both the brothers to have a little "competition". I gave them a task and allowed them ample to time to modify their bots as well as program it.

Overall, the class was a success with both the kids learning the about Robotics as well as Programming. The younger brother even requested that his Dad buy him a NXT set for his coming Birthday :p

Light Sensor Module for NRC 2008

I have decided to build a 3 Light Sensor module to be used in my attempt to conquer the Lower and Upper Secondary category.

Why 3 light sensor? Well, I hope that it would be more accurate than the 2 light sensor as provided by the sample from Sasbadi. In my early attempts to make the vehicle, it is pretty accurate, but still a little slow.

Would need to optimized the program before trying to make it go faster. Speed and accuracy is required if you want to win!! :)

NRC 2008 - Ideas and Thoughts

I have been studying the NRC lower and upper secondary question. I must admit, it won't be an easy competition this year. There are so many things that we could consider. The list is endless, and if you need to test any and every combination, it would be a huge task.

Anyway, I will list down the stuff that we need to consider

Vehicle Design

• Build using studless design, or traditional lego bricks with studs?
• Using the NXT or RCX motor?
• Have 1 or 2 motor as the driving force?
• Do you use gearing to make the vehicle go faster?
• Do you use tracks, 2 or 4 wheels?

Mechanical Arm

• Using NXT or RCX motor?
• When you grab the object is it from top down, or from the sides?

Software

• Design using the Lego NXT-G software or Robolab 2.9?
  

Light Sensor Design

• Do you use RCX or NXT light sensors?
• Do you use 1,2,3 or 4 light sensors?

Overall strategy

• Do we hard code the software to run without considering the tracks (black lines)?
• Do we use a line following algorithm to move through the playing field?

So many different consideration. So many options. I guess, there is no 1 right answer. One may build a better robot, but without a good software design, it may not be able to complete the task and vice versa. To truly win the competition, the team must have a great design, in both software and hardware as well as speed and reliability.

National Robotics Competition 2008 (NRC)

It is the time of the year again, the National Robotics Competition 2008 have just been announced. The question this year is not as simple as it used to be. It would be challenging for all.

You can view more details of the competition from the Sasbadi's website.

The three categories/theme are as follows:-

• Robot Recycling - Primary School Category. Full details here.
  
• Robot Energizing - Lower Secondary Category. Full details here.
• Robot Planting - Upper Secondary Category. Full details here.

Sample robots and sample NXT-G programming have been provided by Sasbadi. I guess that will be the lower bar that we all have to at least meet :0

I have 2 sets of students who would be competiting in the competition. One for the Lower and the Upper Secondary category.

It won't be an easy task! Anyone can build a robot, but can you build an effecient, fast and effective robot?

Can you build the Winning Robot?

Lego Digital Design (LDD)

You must have seen some of the 3D Lego rendering in my previous post. It is not too difficult to get it done, compared to the the previous version of LDD Lego had done. The current version is really easy to use. It is not too complicated and will be perfect for most of us. It may not have as many parts as LDraw, but it should be sufficient.

You can download LDD from Lego directly. Click here to download.


LDD has all the Mindstorms NXT retail kit parts with the quantities stated. You'll be able to design your creation, and know whether will you be able to build it with a standard retail kit, or require extra parts.

Overall it is perfect. You may not be able to build a super complicated design, but it'll be enough for the most of us. What are you waiting for, go and download one today!

Bluetooth Remote Controller for Cars

I have just completed a Bluetooth Remote Controller to control a BT based Car. It is actually the controller for the Car built by one my students. You can see his creation here. As you can see, the BT Remote Controller has an accelerator and a steering built in.


You can build you own Remote Controller based on the LDD file I have provided. It is available from here. A sample NXT-G programming have also been provided for both the BT Remote Controller as well as the BT Car. BT Remote Controller RBT file here. BT Car RBT file here.

Special Lego Robotics Classes

Today I had a another special 1 on 1 class for one of the students. When it comes to Lego Robotics, he is one of the more talented kids out there. From the previous class, I had instructed him to build a car and we would together create and program another NXT Brick as the BT Remote Controller.

As you can see from the following photos, he managed to create a car, using a turntable as a rear wheel differiantial. I know it sounds a little technical but if a 12 year old knows about it, shame on you!! :D

He had built a very simple steering on the front wheels. Not too sure of the name for these sort of steering mechanism, but a more popular styled steering is called the "Rack and Pinion Steering".





He also loves to build Bipeds or Walkers. In the month of March, NXTLog will be having a Biped challenge. I have instructed him to build a Biped and submit it. A little fun and challenge won't hurt anyone. You can read more about the Biped challenge at this link.

Lego NXT Advance Workshop

Today I had 2 students attend the NXTadvance Workshop. Since they were students of the previous tutor, Mr Andrew Lee, I had no idea of their levels whether in Building or Programming the NXT. The students in today's class were age 9 and 11.

Kids being kids, afraid of the media!

The day started out well. Kids being kids at their age had short attention span, not to mentioned that it was their school holidays. We started out by building the BBot.

The purpose was to teach them by examples more advance programming blocks. They needed to understand them before they could program more complicated and advance programs.

"Anybody can follow instructions and build a robot, but not everyone can program it"

Students in disccusions

The kids were very comfortable with building the BBot with the instructions given. After they had completed the BBot, I gave them a list of task to program. With the appropriate guidance, the kids had no issues completing the task on hand.

We proceeded to build more advance robot by the afternoon. Each of them, wanted to build something different. Allowing them to choose what they wanted to build, would encourage them to program it.

They day ended great, with me trying to manage the kids. They were more excited about their new creation, rather than how to write a good program to compliment their great invention. I can't blame them, kids at their age likes to have fun and games!

Eric pictured here with his Lego Tshirt!

A Simpler Grappler

This is my first post on my blog. The purpose of this project is to build a very simple Grappler (Robotic Arm). Because, I wanted to program using a Rotational Sensor block. I could only build a 1-axis robotic arm due to the 3 Tacho Motor and 3 Motor Ports limitation.

As you can, I have also used a very simple programming method. I wanted to test out, and to show how to use very simple Data Wires link between the Rotational Sensor block and the Techo block.