Archive for the ‘Teacher POV’ Category
Programming your robot to make precise turns can be a source of frustration for some students as they begin to learn ROBOTC. Oftentimes, when students are just learning programming, all of the movements of their robots are based on timing. When programming a robot to move forward or backwards, a small error or a small amount of inconsistency can usually be overcome. With turning, however, inconsistencies and small errors can lead to larger errors and the frustration I mentioned earlier.
At this point, students learn that sensors can be used to improve the movement of their robots. With the VEX IQ, a Gyro Sensor is provided that eliminates any guesswork when it comes to programming your robot to turn.
The Gyro Sensor measures the rotational angle of the robot. If you look at the Gyro Sensor, you will see an arrow that points in a counter-clockwise direction. That is the default positive direction. Therefore, as long as the sensor is mounted flat on the robot it picks up the parallel angle to the ground. The sensor then registers the current position as a zero point. If the robot turns counter-clockwise, it registers as a positive value. If it turns clockwise, the sensor registers a negative value. We can see this applied with the following illustration:
We can program the Gyro Sensor using Natural Language or full ROBOTC. To use Natural Language, you just need to make sure that the Gyro Sensor is plugged into port 4. Let’s take a look at some ways to program the Gyro Sensor with Natural Language.
With this program, getGyroDegrees returns the current rotational value of the sensor in units of degrees. When making gyro-based turns, it is best to reset the gyro sensor before each turn, so the resetGyro command is utilized. With the example, we want the robot to turn until the getGyroDegrees command returns a value (from the Gyro Sensor) of 90 degrees. Therefore, we use the repeatUntil command. When we run this program, our robot should make a 90 degree left turn. Note that the robot may turn more than 90 degrees due to drift, which is caused by momentum. If this occurs, just slow down the speed of the motors. That should eliminate the drift.
We can apply the same commands to program our robot to make a right turn.
What I did when first showing the students the Gyro Sensor was to have them see the sensor work with the debugger screen. I used a sample program utilizing full ROBOTC with this activity. The sample program we used was in the Gyro Sensor Folder, and it is called Gyro Display Values. The students compiled and downloaded the program. They kept the USB cables plugged into their robots so they could see the values of the Gyro Sensor on the debugger screen. To access the debugger windows, go to the Robot menu, click on Debugger Windows, and then select Sensors.
The students can now run their program, physically move their robot, and see how the values of the Gyro Sensor change via the debugger screen.
The VEX IQ Gyro Sensor is extremely useful and easy to program, and the students have a lot of fun using this sensor.
- Jason McKenna
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
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:
Move the robot forward for 2.5 rotations:
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);
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:
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
//Move the robot forward for 1.5 rotations (rotations are the default unit) at 50% speed (default speed)
//Turn the robot right for 1.25 rotations at 50% speed (default speed)
//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)
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:
More robot models will be supported in future releases.
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
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.
The ROBOTC Curriculum contains quizzes to help assess what students have learned, or for that matter, what they haven’t learned. However, as we discussed in a previous blog post, one of the great things about teaching ROBOTC is the ability to differentiate instruction to your students. This can present some issues when it comes to assessment. If a student is progressing quickly through the curriculum, he/she cannot have more assessments than another student. Students all have to be assessed equally. This then begs the question of how you can have the students move through the curriculum at different rates while still assessing them equally.
One of the ways I’ve been able to address this is through the use of rubrics, like the one below:
The programmer uses Pseudocode within the comments to display a logical plan to solve the Mission.
Unsatisfactory - No Pseudocode included.
Satisfactory - Pseudocode is included but it does not display a logical plan to solve the mission.
Good - Pseudocode is included and it displays some logical thinking and something of a plan to solve the mission.
Exemplary – Pseudocode displays a logical plan to solve the mission. The plan is well thought out and clear.
The programmer is able to solve the Mission efficiently and repeatedly.
Unsatisfactory - Less than 70% of the mission is completed.
Satisfactory - Between 70 and 80% of the mission is completed.
Good - Between 80-90% of the mission is completed.
Exemplary - All of the mission is completed, and is able to be completed repeatedly.
Unsatisfactory - Code is hard to read and understand.
Satisfactory - Code is readable but is difficult to understand completely.
Good - Code is readable and understandable, but unclear is certain places.
Exemplary - The code is tabbed well and takes good advantage of white space in order to make it very easy to read.
Unsatisfactory - No Comments included.
Satisfactory - Basic Comments are included but some important parts of the code are not explained.
Good - All of the code is commented but explanations could be more complete.
Exemplary - All of the code is commented and the comments are thorough and comprehensive.
The nice thing about this rubric is that the student does not have to complete the programming challenge in order to be assessed. Just like in any other class, students might not learn a concept to mastery on its initial presentation. You never want a student to reach their frustration level, so this gives the teacher an opportunity to clear up misconceptions while still assessing the student.
Another thing that a teacher can do is utilize Exit Slips. Once again, if students are working at different instructional paces, then the Exit Slips can general. You can ask questions like, “What part(s) of the programming challenge were you able to finish today?” This type of metacognition is valuable for students as they complete projects that last several days. Or, the exit slip can be a review of previously learned concepts. Either way, Exit Slips can play an important role in both teaching and assessing.
Fortunately for teachers, robotc.net contains a wealth of information for extension activities. The ROBOTC blog contains a section entitled “Cool ROBOTC Projects.” Here, there is a wealth of ideas that teachers can look at in order to create an interesting activity.
Moreover, the ROBOTC forum contains a section dedicated to projects. This can also be researched in order to find ideas or interesting projects for your class. Also, the forum can be used to ask questions as you begin to plan and implement a project. Here, you really get the best of both worlds: A wealth of ideas and choose from and a dedicated community willing to help you with those ideas.
Have a great school year!
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.
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).
- John Watson
I’ve always been of the opinion that teaching is an art, not a science. Therefore, it’s impossible to devise a scenario that will handle every issue. But, there are some common issues that arise for teachers as they teach robotics and ROBOTC.
Many students come into class familiar with different aspects of technology, but many students will be unfamiliar with some basic things. For example, never assume that students will know how to save a program while using ROBOTC. Secondly, never assume that the students will know where to save their programs. As a teacher, you need to have a plan to cover these things for students. Also, it would be helpful to have a reference for these things for the students. When students return from Christmas Break or a long weekend, sometimes these details escape them.
One things that is very important for teachers who work in classes in which the students are working cooperatively, is for the teachers to identify what is most important and to assess those things. Simply, students get better at things which are measured and assessed. For example, if you want students to use math vocabulary while solving a particular problem involving different wheel sizes, then you need to assess that. If students are working as a group to solve a problem, then each student’s role in that group needs to be defined and assessed.
Additionally, students working cooperatively in groups are always going to be an issue for teachers. The clearer the roles (and how those roles will be assessed) are defined for the students, the better chance you have for success. Still, teachers need to have a plan for those students who just don’t work well in groups. This plan needs to be articulated to the parents and to your administrators at the beginning of the school year.
One of the great things about teaching robotics and ROBOTC is that the first answer is hardly ever correct. This is great because the students are immersed in the problem-solving process. However, some students will become frustrated by this and immediately look to you for the answer. Teachers need to have a plan for these students. How can students work cooperatively to handle these issues? What has been done to prepare for the challenge? Is there a flow chart that the students can review for some ideas? Is there a sample program the students could examine? As teachers gain more experience working through the ROBOTC curriculum, they’ll be able to anticipate these situations more and have an answer for them.
The beginning of class and the end of class oftentimes determine the success, or failure, of a lesson. Teachers should always have a plan for the beginning of class to get the students settled and focused. The more structured this opening activity is, the better. If a routine is developed, the students will respond accordingly. If the students are coming to your class after gym class or lunch, for example, this opening structure will be very important. Examples of class openers could be having the students find errors in code, a review of particular concepts (what is the difference between = and ==), or an Abstraction Bridge.
In much the same way, the closure of the lesson should be used to judge the effectiveness of that day’s lesson. The most popular way to do this is with the use of an exit slip as the students leave the room.
Having a plan allows teachers to work that plan instead of getting frustrated with individual students. Planning your work, and then working your plan will help to allege some of the daily stressors that teachers face.
- Jason McKenna
Eventually your classroom may run into issues with either the ROBOTC software, the robots, or both. The most important question that arises when this happens is ‘Where do I go for help?’ Fortunately, ROBOTC has you covered with an expansive support system designed to help all ROBOTC users get back on their programming feet as quickly and easily as possible. This blog post will take a look at some of the more common issues that you may run into and how to quickly resolve them.
“I am having trouble installing ROBOTC, and do not know why it will not install properly.”
ROBOTC installs like most other programs, but even so you may run into installation issues (depending on your classroom computers’ specific setup). If you run into installation troubles, take a look through our ‘Getting Started’ guide on the ROBOTC wiki as it covers many of the common installation issues that classrooms in particular run into.
“I have installed ROBOTC but am running into issues activating my license.”
First, make sure your license has activations remaining by logging into the ROBOTC customer service page using your license ID and password. Next, check to see if your school’s IT department has recently reimaged the computers; if they have, the license information may have been deployed incorrectly and they will have to contact ROBOTC technical support (below).
“ROBOTC is installed and activated, but my computer will not connect to my robot/won’t load Virtual Worlds!”
There are a variety of reasons this could be occurring (depending on the computer’s set up and the specific robot platform being used), but normally these issue is solved by following the appropriate setup guide on the ROBOTC wiki (LEGO MINDSTORMS NXT, VEX IQ, and VEX Cortex). For the Robot Virtual Worlds software, double check to make sure the computer’s hardware meets or exceeds the minimum requirements as well.
“I have a different question or would like more information on these particular issues.”
There are several resources that can be used when troubleshooting a ROBOTC installation or physical robot issue.
- Coding Problems and Questions – All coding questions should be forwarded to the ROBOTC forums, where the entire support staff may see and answer them.
- Specific Commands, Functions, etc – The ROBOTC wiki is full of useful information including setup guides, programming tips, breakdowns of commands and functions, and more.
- Technical Issues and Bug Reports – For any and all bugs and glitches you may run into, the ROBOTC support line (firstname.lastname@example.org) will be the best mode to contact the ROBOTC support team directly.
The challenge for teachers in today’s educational environment is to teach student at their instructional level. Instead of creating an artificial level to instruct the entire class, teachers have to assess each student’s current level and create a plan to ensure that the student has academic growth from that beginning baseline. It’s best to think about this with an example. A sixth grade student has a reading comprehension at a 9th grade level at the beginning of the school year. The student takes assessments during the spring of that school year. When those assessments are scored, it shows that the student is reading at a 9th grade comprehension level. In the past, teachers and parents would be happy with that information, but the recent push towards differentiated instruction has forced educators to look at this information in a new light. What implications does this have for a robotics teacher?
Luckily, teaching robotics seamlessly fits into the demands of differentiated instruction. First, students are encouraged to come up with different solutions to problems. Whether it is a building challenge or a programming exercise, different students are going to come up with different solutions. Students are encouraged to do this in other disciplines also, but robotics is unique because it is so open-ended. There are only so many ways you can solve a math problem, but there is a myriad of different ways to program your robot to accomplish a task.
Secondly, students who are learning robotics are not forced to conform to an artificial ceiling. In another classroom, a teacher has to keep a student’s learning somewhat in line with the rest of the class. When teachers try to differentiate instruction, they create projects or assignments that are open-ended so students can explore those items as much as they can. However, when that assignment/project is completed, students are all brought back to the same point within the curriculum. Teaching robotics revolves around problem-based learning. Therefore, as the students learn how to solve a programming challenge with more sophisticated ROBOTC code, they are accelerating their knowledge both within that project and within the larger curriculum. While some students are mastering the fundamentals of programming their robot to move, other students can be incorporating more complex programming tools, like functions, into their programs. Robotics teachers can point students in the right direction so they can explore different and more intriguing programming concepts to apply to their challenges. It is not necessary that students memorize all of the different programming/building techniques, but that they know how to access the information when they need it. In this way, students are given the tools to create some ownership with their learning. That ownership, combined with the engagement of robotics helps to provide the true key to differentiation: high student interest.
Simply, if students are not interested in what they are doing, they will never develop the intrinsic motivation needed to push their learning. Students will work towards the minimum unless they are engaged and challenged. Teaching robotics provides the perfect platform to accomplish this goal and create a learning environment in which students are receiving individual acceleration and enrichment. Robotics is the perfect means to achieve the end of differentiated instruction.
- Jason McKenna
Now that the physical robot kits are in the classroom and ROBOTC is installed and activated, you should be ready to build the physical robots for your classroom. One of the best features of a VEX Robotics kit is that they allow students to create a nearly limitless range of robots; the downside of this, however, is maintaining student-created robots in a classroom. To help with this, ROBOTC and the Video Trainer Curriculum support several standard models to help keep a baseline in the classroom.
The first of such robots we will look at is the VEX Squarebot (using the VEX Cortex), one of the standard Cortex models that are used in the VEX Cortex Video Trainer for ROBOTC. The Squarebot utilizes three VEX motors (two for driving, one for the arm), and a wide variety of sensors. These sensors include Quadrature Shaft Encoders, a Sonar Sensor, and a Potentiometer (among others; in total, there are 8 separate sensors on the Squarebot). This model allows for a variety of tasks to be completed and is designed to work with all of the challenges in the ROBOTC Curriculum.
A smaller, different alternative Cortex standard robot is the Swervebot. Like the Squarebot, the Swervebot utilizes the VEX Cortex as its main processor and uses two VEX motors for driving. However, the Swervebot’s small chassis does not utilize an arm. Instead, the Swervebot makes clever use of an Omniwheel in the rear for turning and boasts three Line Follower sensors and a Gyroscope (as well as 6 other sensors, for a total of 10) and is perfect for smaller classroom environments.
Finally, the new VEX IQ platform can be quickly assembled and ready to use in a classroom thanks to the IQ Clawbot standard model. Using 4 motors total (two for driving, one for the arm movement, and one for gripper control), the VEX IQ Clawbot can be controlled either autonomously using the VEX IQ sensors (such as the Bumper Switch and Color Sensors), remotely using the IQ Controller, or a pleasant mix of both, depending on which kit is being used.
Visit CMU’s Robotics Academy VEX site for more information on the different kits available and to find build instructions.