# ROBOTC.net Blog

ROBOTC News

## Student POV: Slalom Challenge

It’s Danica and Jake, back again! This time, teaching people about the slalom challenge, in ROBOTC Graphical Language for the VEX IQ platform. The challenge is to line follow using the VEX IQ color sensor without hitting the “mines”, also known as the cups.

In the graphical organizer, to line follow on the left side of the line, all you have to do is use the block, lineTrackLeft, to follow the right side you have to use lineTrackRight.

In this block, there are 3 boxes, one for the threshold, the second for the speed of the left motor, and the last box is for the speed of the right motor. In this line of code, the threshold of 105, the robot’s left motor is set to go at 50% power, and the right motor is set to go at 15% power.

This block has to be included into a repeat loop to make sure the robot continues to do this command for an allotted amount of time.

The repeatUntil loop has many options for how long the loop should run. For this challenge, we decided to use the timer.

The timer is set at 7000 milliseconds or 7 seconds, so it has enough time to make it through the slalom. Our finished program looks like this:

Now you can line follow in any challenge you would like, the possibilities are endless!

Written by Cara Friez-LeWinter

April 2nd, 2014 at 7:47 am

## Student POV: Robo 500 Challenge

Hi, we’re Alexis and Noah, two eighth grade students at Hopewell Memorial Junior High School. Earlier this week, we did the Robo 500 challenge. To write the programs, we used the recently released ROBOTC Graphical software for the VEX IQ. The goal of the challenge was to complete two laps around a Vex IQ storage bin.

We completed the challenge by using timing and degree measurements. The first step was to get the robot to move forward. For this, we would use a basic motor command.

In ROBOTC Graphical, it gives you the option to choose the values in which you want your motor to run by, such as time and rotations. In this challenge, we chose time.

From there, we experimented with different time values until we found the timing that was needed to finish the side of the challenge before the turn. Through testing, I found that 3.7 seconds covered the distance needed.

Now, what was left was the largest challenge of the program, the turn. Timing a turn can be challenging on seconds alone. So, I used degree turns. I started with a 180 degree, which brought me around about 45°. Due to the drift of the robot when it moves forward, I had to make the turn slightly less than double the 180° turn. I settled on a value of 300°.

Once the values were established, the rest was just repeating the commands so the robot would go around the whole box. Here is an example of my final program.

We were then thinking about how the turns were a hassle with trial and error, and contemplated a better way to turn. So, we decided to use a gyro sensor to have the most accurate turns possible.

To start out the program we had to reset the gyro sensor so the sensor could record the degrees from zero.

From here we moved forward to the end of the course for time, and we moved forward for about four seconds. Then we used a while loop. A while loop is set to check a condition and while the condition is true, it performs what is inside of the curly braces of the while loop. In this case the condition is while the gyro sensor value is less than 90 degrees.

We would then repeat these actions until the robot has made two full laps around the course. Here is the program for one lap. To do two laps I would just repeat this program again.

We were able to finish our programs efficiently in a short amount of time due to the design of the new graphical programming. This new design enables you to drag over commands from the function library; such as, moving forwards and backwards, turning, and sensor commands while avoiding the hassle of painstakingly typing each command. This reduces the time spent on each program and allows us to speed up the pace at which we program, and we are able to complete challenges in a shorter amount of time.

To the left, we have an image of the function library and a depiction of what would happen if you dragged a command into your program. The command would line up with the next available open line and would give you options as to what values you wanted to program your robot with.

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If you’re a student who would like to contribute to the blog, let us know at socialmedia@robotc.net.

Written by Cara Friez-LeWinter

March 26th, 2014 at 7:30 am

## Student POV: Labyrinth Challenge

We are really excited to introduce a new blog series called Student POV! This series will feature students giving their perspective and advice for programming in ROBOTC. If you’re a student who would like to contribute to the blog, let us know at socialmedia@robotc.net. Welcome our first student bloggers, Danica and Jake!

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Hi it’s Danica and Jake, and we just completed the Labyrinth Challenge. We are both 8th grade students attending Hopewell Memorial Junior High. We both used VEX IQ Graphical Programming Language to complete this challenge since it is a new software recently released by ROBOTC. The first challenge we had to accomplish was the labyrinth challenge. The labyrinth is a square, where the robot has to travel from the starting point, to the ending point by doing a series of basic commands.

Our first task was to make our robot move forward.

This block is telling the robot to go forward at 50% power for 5 rotations, but you can also set the robot to move for degrees, milliseconds, seconds, and minutes.

Our second task was to make the robot turn left.

When turning left, you can use multiple commands such as degrees, rotations, milliseconds, seconds, and minutes. You can also use this for turning right.

One problem while programming for this challenge was making 90 degree turns. To get a perfect 90 degree turn, with timing, you had to go through a lot of trial and error. After figuring out the perfect turns, based on timing, the time for moving forward, and the stops to prevent drifts, we had to string all the commands together to form the program for the challenge. This what the finished program looks like:

An easier way to perform more accurate turns, is with the use of the gyro sensor. The gyro sensor allows you to count how many degrees you turn. This simply means that you can actually tell the robot to make an accurate turn. You also have to remember to reset the gyro after every use, and it will make this program a lot easier.

To reset the gyro you have to use this block:

The finished program with the gyro sensor looks like this:

In this program we used the setMotor command instead of turnLeft or turnRight. This command is better to use in the while loop since you only have to set the speed of the motor. The condition in the while loop determines how long the robot turns. As a result, we just need to set the motor speed with the setMotor command.

A cool feature you can use in RobotC is commenting out your code. You can also do this in the VEX IQ Graphical Organizer. It is much easier though since you only have to click the number on the block of code you want to comment out.

Commenting looks like this:

These comments allow you to test only one turn out of the whole code, which is very useful during the trial and error stage.
Now it is time to go try the Labyrinth challenge on your own, either with or without the gyro sensor. Have fun!

Written by Cara Friez-LeWinter

March 19th, 2014 at 4:29 pm

## A Teacher’s POV: Fun With VEX IQ Remote Controls

Whether they are in elementary school, middle school, or high school, students really enjoy programming their robots with remote controls. Luckily, the VEX IQ wireless controller allows you to do just that. ROBOTC allows you to create your own remote control programs to customize each joystick axis and button controls. Moreover, you can use both Natural Language and full ROBOTC with the remote controls.

Both the VEX IQ brain and the remote control require a radio controller for communication. The radio controller has to be in each in order to use the remote control. Additionally, a battery needs to be placed into the remote control for the wireless communication. Just like the battery for the VEX IQ brain, the battery for the remote control is rechargeable.

In order for the VEX IQ brain and the controller to communicate, they must be paired together. With both devices turned off, connect the two devices together with the tether cable that is included with the VEX IQ Starter Kit with Controller. The tether cable is just a standard Ethernet cable. Turn on the VEX IQ brain by pressing the check button. The controller will automatically link and pair with the VEX IQ brain.

Once your connection has been established, the green light will blink on both the remote control and the VEX IQ brain. You will not have to link the tether cable with the remote control the next time you turn on the VEX IQ brain or the remote control. In the classroom, you can assign each robot to a remote control by giving each a number. That way, you never have to link the remote control with the VEX IQ brain. Or, you can just have the students do a quick set up at the beginning of class. Either way will work.

ROBOTC can access all of the data from the VEX IQ remote control by referencing the button and axes by their described names. Joystick buttons return values of..

• 1 – Pressed
• 0 – Not Pressed/Released

Joystick Axis return values of…
• -100 to +100 (0 when centered)

When using the VEX IQ remote control, make sure you switch to your “Controller Mode” to Tele-Op.

Alright, now you can begin programming (either in Natural Language or full ROBOTC) and have some fun.

As teachers, we all know to expect the unexpected. I recently had the students on a Friday, with a long weekend in front of them. Therefore, I did not want to start a new concept, for I would have to re-teach it after the long weekend. So, I decided to set up a quick in-class competition with the VEX IQ Challenge Field and some Bucky Balls and rings.

I allowed the students to make up the parameters for the game, gave them some time to devise some strategy, downloaded some sample programs to run the remote controls, and let the fun begin. The students had a great time and the activity will serve as a springboard for future investigation into how to customize the remote control programs.

– Jason McKenna

Written by Cara Friez-LeWinter

February 4th, 2014 at 9:55 am

## ROBOTC Graphical Natural Language

We know that text based languages (such as ROBOTC) have advantages in terms of customizability with functions, complexity with algorithms and calculations, and typically smaller sized programs over graphical languages; however, it is difficult to overcome the simplicity and ease of use that “Drop and Drag” programming languages offer to new users just getting started with programming.

A few years ago (with ROBOTC 3.X), we announced our “Natural Language” feature – a simplified library of commands that used “natural” commands to control your robot, such as Forward, Reverse, and LineTrackForTime. The Natural Language feature was designed to help ‘bridge the gap’ between a graphical language and the text-based ROBOTC. Teachers have praised ROBOTC’s Natural Language for making it easier to get their students up and running faster than ever before. Currently, ROBOTC supports Natural Language on the VEX Cortex, VEX IQ, and LEGO MINDSTORMS NXT platforms for both “Real” and “Virtual” robots.

Today we’re proud to give you a sneak peek to a new feature we’re calling “Graphical Natural Language”. This new interface will allow you to program robots from inside ROBOTC with easy-to-use graphical blocks that can be drag-and-dropped to form a program. Each block represents an individual command from the “text-based” ROBOTC and Natural Language.

Each block is custom designed to fit the needs for that specific function and parameters. Using text boxes and drop-down menus, users can customize each values of each function to solve various challenge and activities using the same commands as ROBOTC’s Text-Based Natural Language.

We have also added some new language extensions to both ROBOTC and Natural Language, such as the simplistic “Repeat” command. Prior to the Repeat command, users would need to copy and paste large sections of code or use a looping structure (like a ‘for’ or ‘while loop) in order to have a set of actions repeat a certain number of times. With the new “Repeat” command, however, users can simply specify how many times they would like for the code to run, with no complex coding required.

Another awesome tool that we’ve implemented in ROBOTC 4.0 is the “comment out” feature. You can now comment out an entire line of code just by clicking on the block’s line number. Lines of code that are “commented out” are ignored by the robot when the program is run, which makes this feature very useful when testing or debugging a program. This new tool is unique to Graphical Natural Language.

Because each Graphical Natural Language block corresponds to a real ROBOTC or Natural Language function, users will be able to graduate from Graphical Natural Language to full text-based Natural Language with the press of a single button. This will allow you to naturally transition from Graphical Natural Language to the text based Natural Language (or ROBOTC), without having to worry about manually converting the code line-by-line!

We have many other features and enhancements planned for Graphical Natural Language – Be on the lookout for a preview version sometime in January!

Please Note: The screenshots and interface in this post are not the finalized version of the ROBOTC Graphical Natural Language – the names, interface, look and feel of the system may change between now and official release.

Written by Tim Friez

December 19th, 2013 at 6:18 am

## A Teacher’s POV: Programming the VEX IQ Robots

In the previous entry, I shared some of the features of the VEX IQ robots. Also discussed were some ideas on how to get a classroom organized. Now that we have those things established, we can move on to a discussion of how to begin programming the VEX IQ robots.

ROBOTC for VEX IQ has Natural Language commands that will help beginning programmers of the VEX IQ by supplying a set of commands that use “natural” words. For example, the “forward” command will make your robot move forwards for a specified amount of time or distance. The robot will come to a stop after the movement. Here are some examples of the command:

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Move the robot forward for 2.5 rotations:
• forward(2.5);

Move the robot forward to 180 degrees:
• forward(180, degrees);

Move the robot forward for 1.5 rotations at 30% speed:
• forward(1.5, rotations, 30);

Move the robot forward for 10 seconds:
• forward(10, seconds);
• forward(10000, milliseconds);
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Natural Language also contains other helpful commands; such as, “backward”, “turnLeft”, “turnRight”, and “repeat”. Below is an example of a Natural Language sample program that is located within the Natural Language sample program folder in ROBOTC:
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/*
VEX IQ Natural Language – Port Names and Numbers
leftMotor – Port #1
rightMotor – Port #6
armMotor – Port #10
clawMotor – Port #11
touchLEDSensor – Port #3
gyroSensor – Port #4
distanceSensor – Port #7
bumperSensor – Port #8
colorSensor – Port #9
*/

{
//Configure the Natural Language to use the VEX IQ Clawbot
setRobotType(VexIQClawbot);

//Move the robot forward for 1.5 rotations (rotations are the default unit) at 50% speed (default speed)
forward(1.5);

//Turn the robot right for 1.25 rotations at 50% speed (default speed)
turnRight(180, degrees);

//Move the robot backwards for 720 degrees at 25% speed.
backward(720, degrees, 25);

//Turn the robot left for 2.5 rotations at 50% speed (default speed)
turnLeft(2.5, rotations);
}
——————————————————————-

As you can see, there are a couple things that we have to do in order to use the Natural Language functionality. To enable Natural Language, go to “Robot Menu -> Platform Type -> Natural Language”.

The easiest way to get started programming is to open a sample program or to use a template. To open a sample program in ROBOTC, go to File Menu -> Open Sample Program.

To use a Natural Language template in ROBOTC, go to File Menu -> New… -> Natural Language Template.

To make programming easier, Natural Language makes assumptions about the type of robot you are using. To configure your Natural Language program to use our VEX IQ Clawbot, use the following line of code:
——————————————————————-
setRobotType(VexIQClawbot);
More robot models will be supported in future releases.
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Finally, you will notice in the sample program that port names and numbers are given specific names and ports. Make sure that your VEX IQ Clawbot’s motors and sensors are configured this way in order to work with the Natural Language commands.

Ok. We are ready to go with programming! What should we do? My suggestion would be to start with the Labyrinth Challenge.

The Labyrinth challenge gives the students an opportunity to engage with the VEX IQ robots and ROBOTC. The students are immediately engaged because they can see and test their robot’s movement as it makes its way through the course. Since this may be the first program that some students write, there are a couple of things worth remembering. First, makes sure the students create a flowchart before they begin programming. For more information on flowcharts, you can look here: VEX Teacher – Engineering.

Second, it is important that the students describe what is going on in their programs with comments. For more information on how to utilize comments, please see here: http://www.robotc.net/vex_full/reference/hp_comment.pdf

Now you are ready to go! Good luck and have fun! Remember, if you have any questions as you are working, please visit the ROBOTC forums.

– Jason McKenna

Written by Cara Friez-LeWinter

December 13th, 2013 at 6:41 am

## A Teacher’s POV: Getting Started with the VEX IQ

The VEX IQ robot is a great, new option for middle and high school robotics teachers. With anything new in the classroom, it’s important to have some ideas on how to best implement the new tools in the classroom.

There are some features of the VEX IQ system that teachers will notice initially. The VEX IQ brain has 12 identical ports. This means that any device (either a sensor or a motor) can be plugged into one of the ports. Also, the VEX IQ motors are smart motors; therefore, the motors can hold a position and resist external movements. Some of the sensors for the VEX IQ include a Bumper sensor, a Touch LED sensor, a Gyro Sensor, a Color sensor, and a Sonar sensor. One nice asset of the motors and sensors is the fact that they each have their own upgradeable firmware. As a result, if new features are added, the firmware for the device can be upgraded, as opposed to buying a new sensor and/or motor.

With the VEX IQ Starter Kit, there are over 850 structural and motion components. That many parts allow teachers and students lots of flexibility when it comes to building a robot. But, that’s only if they can find the parts they need. One of the first things that teachers need to do is get their kits organized. The Starter Kit comes with a storage bin and tray that help, but the amount of parts means that different pieces will need to be stored together in the storage bin. If the students know what pieces are located in each section of the storage bin, it will make the building process much easier.

The base robot for the VEX IQ is the Clawbot. The Clawbot include a gripper and a lifter arm. These features immediately grab the attention of most students; they love the idea of being able to lift and grab an object. For teachers, it is a good idea to build the Clawbot before allowing the students the opportunity to do the same. This gives teachers an idea of what problems the students may have as they begin building, and it also allows the teachers to help those students that run into problems. You can’t start anything until all the students have their robot built. Having some groups finish their robot, while other groups lag behind can be an issue. Building a robot first, puts the teacher in the best position to get everyone started off on the right foot.

When it comes time to start building, students can work on different parts of the VEX IQ Clawbot. You can divide the Clawbot into these sections: the Base, the Claw, the Tower, and the Ball Holder. One suggestion to organize a class would be to have two students work on the Base, while one student each works on the Claw, the Tower and the Ball Holder. Or, you could have one student work on each section. It’s important to note that however the class is organized for the building of the Clawbot, there should be a uniform way that the students attach the motors and sensors.

The battery for the VEX IQ robot brain comes charged, so a teacher does not need to worry about doing that preliminarily. So, once the Clawbot is built, the next thing that needs to be done is install the ROBOTC firmware and update the VEX IQ brain, motors, and any sensors that may be on the robot. Click here for directions on how to install the ROBOTC Firmware.

To update the VEX IQ brain, motors, and sensors, the VEX IQ Firmware Update Utility needs to be downloaded to your computer. The Firmware Update Utility and directions on how to utilize it can be found here.

With the next installment, we will take a look at how to set up your first programming lesson. In the meantime, teachers can take advantage of a few readily available resources at Carnegie Mellon’s Robotics Academy VEX Teacher Site and the ROBOTC Wiki to help with questions concerning programming the VEX IQ with ROBOTC.

-Jason McKenna

Written by Cara Friez-LeWinter

December 5th, 2013 at 4:43 pm

## RVW FTC Block Party Competition Now Live!

Carnegie Mellon’s Robotics Academy, a research-based organization committed to teaching students how to program robots, is really excited to be able to support FTC teams again this year. Follow the links below to learn about FREE Programming Classes and a new Block Party Programming Game that can be used by students, teachers in classrooms, coaches, or competition providers. The new game is designed to teach programming and has over \$5,000 in prizes. We’ve also made CS2N Groups Technology that enables teachers, coaches, and regional competition sponsors to host their own competitions.

In the FTC Block Party Virtual World, program one of three robots to score as many points as possible in autonomous and driver controlled modes. Score points by:

• Placing Blocks in Floor goals
• Placing Blocks in Pendulum goals
• Raising the Flag
• Hanging from the Bar

See the rules documents for the full game explanation:

How to Setup Your Own In-Class Competition – Teachers, coaches, and competition organizers can setup their own unique programming competitions using CS2N Groups Technology.  The Robotics Academy has developed groups technology that enables teachers to setup their own in-class competitions.  To learn how to setup your own Group competition click here: http://www.cs2n.org/tutorials/competitions

Be sure to visit the CS2N.org or RobotVirtualWorlds.com for the latest version of the FTC Block Party software. Happy Programming!

Written by Cara Friez-LeWinter

November 20th, 2013 at 6:49 am

## RVW VEX Toss Up Competition Now Live!

Carnegie Mellon’s Robotics Academy, a research-based organization committed to teaching students how to program robots, is really excited to be able to support VEX Competition teams again this year. Follow the links below to learn about a NEW VEX Toss Up Programming Game that can be used by students, teachers in classrooms, coaches, or competition providers with FREE Programming Classes that your students can take. The new game is designed to teach programming and has over \$5,000 in prizes. The Robotics Academy has also developed CS2N Group Technology that enables teachers, coaches, and regional competition sponsors to host their own programming and remote control virtual competitions.

VEX Toss Up is played on a 12’x12′ square field. The object of the game is to score your colored BuckyBalls and Large Balls into the Near Zone and Far Zone, by Locking Up your colored BuckyBalls and Large Balls into the Goals, and by Low Hanging, Hanging and Ultra Hanging off your colored Bar at the end of the match.

This Virtual World is designed to simulate the Toss Up competition field and several robot designs, allowing teams to practice their programming and form winning gameplay strategies.

See the rules documents for the full CS2N game explanation:

1. VEX Toss Up – Autonomous CS2N Mode
2. VEX Toss Up – Remote Control CS2N Mode

How to Setup Your Own In-Class Competition – Teachers, coaches, and competition organizers can setup their own unique programming competitions using CS2N Groups Technology.  The Robotics Academy has developed group technology that enables teachers to setup their own in-class competitions.  To learn how to setup your own Group competition click here:http://www.cs2n.org/tutorials/competitions

Be sure to visit the CS2N.org or RobotVirtualWorlds.com for the latest version of the VEX Toss Up software. Happy Programming!

Written by Cara Friez-LeWinter

November 12th, 2013 at 6:44 am

## Advanced ROBOTC and Robotics in the Classroom

So your class has gone through the ROBOTC Video Trainer Curriculum (VEX or LEGO), are comfortable programming in ROBOTC, and the robots are starting to zip across the room: however, some students are absorbing the programming knowledge quickly, while others are taking a little longer to grasp the core concepts. Where should a teacher look to if a student (or classroom) advances beyond the pace of the class? In this post, we will take a look at some of the many advanced programming resources available for ROBOTC.

Because ROBOTC is a C-based programming language, there are many C programming features that students can lean about and implement in their code. The first resource to investigate is the ‘Programming Tips and Tricks’ section of the ROBOTC wiki. This special subsection contains samples of some of the more advanced C-based operations that can be executed using ROBOTC and are pulled from a variety of sources. Topics include structs, switch statements, tertiary operators, and more. Because all of the information is available for free online, students can research and test the topics at their own pace and gain a deeper understanding of the subjects.

An example of an advanced program using a while loop as a counter

Next, you may want to take a look at tutorials on the ROBOTC wiki for implementing advanced programming concepts with different sensors. Also be sure to check out ROBOTC’s Sample Programs (via the ‘File -> Open Sample Programs’) as many of the programming concepts have pieces of advanced code that can help the students understand exactly how they are applied in real-world scenarios. There are also several multi-robot projects (for the NXT) that can be found on ROBOTC’s Multi-Robot wiki and a thread dedicated to advanced ROBOTC programming with VEX which will both offer unique challenges for students to conquer, as well as a wealth of community created projects showcased on the ‘Projects Discussion‘ section of the ROBOTC forums.

Once the students have sufficiently expanded their knowledge of advanced ROBOTC programming, they will be ready to tackle more complex robotics projects. This is a perfect opportunity to encourage creativity and inventiveness with preexisting challenges (and is a perfect example of where differentiated instructions can positively impact a classroom). By utilizing differentiated instruction in the classroom, you will be able to not only challenge the newer programmers with the basic programming examples, but will also be able to engage the more advanced students with complex programming options, such as making their robots perform a challenge quicker, more efficiently, or more accurately (or a mix of all three).