How can you calculate the circumference of a //code.Node Cart wheel
and use it to determine distance traveled?
[Wheels: Diameter and Distance]
One of the great things about the //code.Node Cart is that
it can be used to reinforce various topics.
It can be used with physical science in mind, coding applications, as well as mathematical applications.
This activity not only has a focus on coding with functions,
but also reinforces the formula for circumference of a circle
and how to use it to solve problems.
The only materials needed are the cart, //code.Node, and access to SPARKvue software.
This lab is broken up into five activities:
determining wheel circumference, using circumference to determine distance,
investigating the magnetic field sensor, programming--creating a rotation counter,
and then a final challenge of coding diameter and distance traveled.
Keep in mind, if students have not had experience in calculating circumference,
they may need some additional support with the first two sections of the lab.
Once students have calculated the circumference of the cart's wheel,
they will spend some time reverse engineering how the cart determines position
using the bar magnet on the axle of the cart,
along with the magnetic field sensor within the //code.Node.
I'm going to jump to the third activity, where students are going to be
doing some reverse engineering and understanding how this cart actually determines its position.
They will look at the magnetic field sensor on the back axle.
Then they're asked to set up a track of a half a meter.
This is an important part.
The students need to make sure that they know to start this wheel in the same position every time.
Let me show you how that works.
I'm going to go ahead into SPARKvue and hit Sensor Data.
For this activity, we're going to use the magnetic field strength.
I'm going to disable the other sensors,
and bring up a line graph
that's going to show me magnetic field strength over time.
On the bottom left-hand corner of SPARKvue, you see your live data bar.
Right now, it's telling me, negative 1.8, positive 2.0.
For this activity, it's important to get as close to zero as possible.
Maybe even mark your wheel with an arrow, so the students know where to start.
You'll see why this is important in a second.
Let me get it as close to zero as I can.
Almost there, and I'm going to click Start.
You can see on the data bar, it's pretty interesting.
They can use this data to gauge how many rotations the wheel has made.
They do some investigating with this. They do it multiple times, and they recreate the graph.
Then they're charged with coming up with a program-- this is activity four--
where they have to come up with a rotation alarm.
They can use any coding that they want, but the end game is to make sure that
they have something that gives you a beep every time this wheel makes a full rotation.
I've gone ahead, and I have an example of the program.
You'll also find this in the teacher version of the document.
I'm going to open that up.
Take a look at our program here.
This example states that as soon as it goes to a positive gauss--
that's the unit of measure for the magnetic field strength--
it's going to give me an indicator beep.
If it's below, it will not make any noise at all.
Let's see how this works.
I'm going to bring back up my graph,
because I want to be able to see this data bar again.
As close to zero as I can. Click Start.
It's pretty interesting.
As they run through this, they're going to see when they hit those peaks,
it's going to give them an alarm saying, "I've done a rotation."
Actually, when you're looking at the data,
this is a half rotation when I'm looking at this first piece here.
Then that dictates another half rotation.
That's one coding program example. Again, you'll have that in the teacher version.
The next challenge, the students are given the code.
This is where they're going to have to plug in the circumference
that they calculated for the wheel of the cart.
Let's open that one.
I'm going to go ahead and show you the program.
It's a bit more advanced, because they're using functions.
They're actually creating a mathematical application in here
saying that it's going to take the position of the cart.
Again, they're going to go half a meter to start.
They're going to plug in that circumference.
They're going to be able to have a counter that not only shows you the magnetic field strength
for those peaks and valleys, but now you're going to see a number
that'll correlate with how many full rotations you have on the cart.
I'm going to go back here.
For this one, I want to add a new page.
I want you to be able to see the magnetic field strength.
You see I've run this program many times. User entered for rotation.
Let me clean that up for you.
I'm going to manage these runs and delete everything.
Check the program. Everything looks good.
Let's give it a whirl.
Again, I need to start as close to zero as I can.
Pretty good, and Start.
It's telling me that I've done about four full rotations and a half rotation.
I can look at this data bar and see how the magnetic field strength and this correlate.
That is the last challenge program in that activity.
This activity may need to be broken up over a couple days.
Once students have completed all the activities,
they will have the knowledge they need to complete the questions
in the question and analysis section of the lab.
You can access the student and teacher versions of this activity
in our teacher resource center at pasco.com.
Keep in mind, you can always challenge students to extend their coding programs,
such as not only showing how many rotations the wheel completed
in a numerical output on the SPARKvue screen,
but also showing the number on the 5x5 LED array itself.
Thanks so much for watching.
Don't be afraid to let your students come up with other activities that use the //code.Node Cart.
The possibilities are endless. You will find they can teach us a thing or two.