It’s that time of the year again — the Commonwealth Games are nearly here! Why not get into the sporty spirit by making your very own interactive stadium, complete with sound effects, a sprinting event, and an electronic scoreboard? We can show you how! All you need is a little bit of cardboard, some strips of alfoil, and the assistance of Scratch and Makey Makey.

 

Step 1: Build the stadium using cardboard (and your own creative genius)

Ready to bring out your inner artist? Great! Using some cardboard, fashion yourself a good ol’ stadium. Now, there’s more than one way to go about this, so instead of limiting your creativing by giving you a step-by-step instruction manual, here are some pictures for inspiration:

 

Step 2: Add stadium sound effects using Scratch

Now that you have the stadium built, let’s jazz it up a bit by adding some sound effects using Scratch! You can add sounds in two ways: you can (a) record your own sound effects, or you can (b) use Scratch’s in-build effects library, where you can find relevant sound effects such as:

  • Music
  • Clapping
  • Cheering
  • Crowd noises
  • Splashing sounds (for swimming or diving events)

 

To do either of the aforementioned, you’ll have to navigate to the Sound tab in Scratch.

 

The  icon will allow you to browse through Scratch’s in-built sound library. If you see a sound effect that you like, make sure to select it and then click OK. Once you do this, your desired sound should appear in the sound tray, like so:

 

 

 

How do we add stadium sound effects using Scratch, you ask? Look to our pre-made Scratch code for answers!

 

 

If you experiment with some of the keys on your keyboard, you’ll figure out that certain keys cause certain sound effects to play. For example:

  • The space key plays the opening ceremony music
  • The right arrow key plays the sound of someone diving
  • The up arrow key plays the sound of clapping
  • The down arrow key plays the sound of cheering
  • The left arrow key plays the sound of the opening ceremony singer
  • The ‘a’ key plays another cheering sound

 

So how do we trigger the sound effects? We can do it by using an Event block to play a sound, as you can see below in the picture:

 

 

The orange blocks that you see in the picture above are the Event blocks that we mentioned earlier. When an event occurs — in this case, when a certain key is pressed — our purple Sound blocks are executed. Thus, we get a chain reaction, whereby pressing a certain key triggers a sound effect.

We can extend the functionality of our interactive stadium by introducing Makey Makey into the mix. Instead of having to control our stadium using the keyboard, we can create a Makey Makey controller to make a more interesting and unique interface out of anything from buttons, to coins, to fruit and lollies!

 

Step 3: Adding an electronic display board using Scratch and basic electronics

By now, you should have a cardboard stadium that is fully equipped with sound effects. But it can hardly be a stadium worthy of the Commonwealth Games if we don’t have any events, right? With the help of Scratch and basic electronics, why don’t we make a sprint event to be the focus of our stadium? And, while we’re at it, why don’t we make an electronic scoreboard to record the times that it takes our athletes to complete the circuit? (No pun intended!)

There are three things that we’re looking to achieve in this step:

  1. We need to make a sprinting event, complete with a (cardboard) track and (cardboard) athletes
  2. We need to write a Scratch program that will:
    • Start a timer
    • Record the times that it takes for our athletes to finish the event
  3. We need to connect certain components of our event to our Makey Makey, in order to make said event fully interactive!

 

Making the sprinting event

Let’s start by making our athletes. You can theoretically make your athletes out of whatever material you like, but for the sake of this guide, let’s make them using cardboard and paddle pop sticks, kind of like this:

 

 

Once you’ve made your cardboard athletes, wrap some aluminium foil (or some other conductive material) around the base of it. I’ll explain why very soon!

Once you’ve made your athletes, make your cardboard track. Cut four slits lengthways through the cardboard, to serve as “lanes” along which your athletes can run. Line the uncut end of the cardboard with alfoil. You should end up with something like this:

 

If you’re wondering what I mean by “positive terminal” and “ground”, then don’t worry — I’ll explain that in just a bit. For now, let’s move on to making the Scratch program!

 

Making the Scratch program

Next, let’s work on our Scratch program! For your reference, you can click here to check out the project that we did up a little earlier.

Before we get started, let’s break down what we need to do:

  1. We need five sprites: an announcer, and the four athletes
  2. We need to program the announcer to count down from 3, and then start the timer
  3. We need to program each of the four athletes to say what time they finished the race

 

 

The athletes

For each athlete, we need to assign them a different arrow key. For example, here are the keys that we assigned to our athletes:

  • Athlete 1 is assigned the up arrow key
  • Athlete 2 is assigned the down arrow key
  • Athlete 3 is assigned the right arrow key
  • Athlete 4 is assigned the left arrow key

(Helpful hint: If you programmed any sound effects onto these arrow keys, you may want to move them to a different key, unless you want a sound effect to play precisely when your athlete finishes the race!)

The code that we want to put on each athlete will look roughly like this:

 

 

In other words, when an athlete’s assigned key is pressed, the program will tell us the time at which this action happened.

 

The announcer

As you can see in our code, the announcer sits in the top right corner. We’re using the sprite Abby as our announcer, but yours can be anything from Abby to an apple to an aardvark.

When we click the green flag to start the project, we want our announcer to count down from three, and then start a timer. You can do this any number of ways, but this is the way that we’ve chosen to do it:

 

 

After the announcer counts down from 3, she broadcasts a message that says start timer. When the message is received by the when I receive [start timer] event, the timer on all athletes will be reset. In other words, the race will start all over again.

 

Adding Makey Makey to the mix

Get out your Makey Makey — it’s time to put everything together!

Remember our cardboard athletes and our cardboard track? We’re going to need to connect it to the alfoil bits on our athletes, as well as the alfoil on our track. First, connect the ground on your Makey Makey to the alfoil on the end of your cardboard track. Then, connect each individual athlete to their corresponding arrow keys on your Makey Makey (i.e. the ones that you assigned them in the Scratch project). Like so:

 

 

So, what’s going on here? Each of your athletes are going to function as positive terminals, and our alfoil finish line is going to serve as ground. All you really need to know is that, as long as the positive terminal is not in contact with the alfoil, nothing will happen. In other words, if the athlete is not touching the finish line, the event we programmed to occur (i.e. the timer stopping) will not occur:

 

 

On the other hand, when our athlete reaches the finish line — or, in other words, when the positive terminal makes contact with the ground — the circuit will be complete, and our desired event (i.e. the timer stopping) will occur:

 

 

Now go ahead and test your creation! Are the athletes’ finishing times recorded when they reach the finish line?

 

Congratulations!

You should now have a fully-functioning interactive stadium! With all that being said and done, don’t feel the need to limit yourself to just sprinting events. Think about how you can apply the concepts that we’ve learned to other events: how can you make a swimming event, a biking event, or some other kind of event using the concepts that we’ve learned?

 

If you had a ball making your own interactive stadium, you should know that there’s more where that came from! At Coding Kids, we run our own teacher PD sessions, so that you as a teacher can learn how to teach tech projects just like this one. If you’re interested in learning more, drop us an email.

 

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