What is the fastest way for Marty to move? Walking forward? Sliding sideways? Using Scratch 3, you will code a countdown timer that starts and stops Marty moving. You can then change the way that Marty moves and see how far Marty goes! If you want to take this further, you can measure the distance Marty has travelled and work out Marty’s speed.

Masking tape or equivalent to mark a start line

How to calculate speed from distance and time measurements

How to use event, control and operator blocks

This activity can be linked to concepts covered in the lesson packs 

As this activity uses concepts from Physics often investigated when studying forces and motion, the activity also partially addresses benchmarks in the following curriculum areas:

We are going to start by making a simple countdown timer that ticks down in seconds.

We want to code a timer that counts down by a set number of seconds. To do this we want to make a variable. This variable is for the total number of seconds that our timer is set for. To make a new variable, select the 

 option in the code blocks drawer followed by the 

 button. You will be asked what you want to call your variable, we called our variable 

: You can change how long your timer runs for by setting 

To count down, we want to wait for one second then reduce the value of the time variable by one.

Set the gap variable to 1 second. Then we want to add a change variable block from the Variables option in the code blocks drawer and set it to -1.

Because we want our timer to count all the way down to zero, we want to repeat this step until the timer reaches zero. To do this easily, we can make use of a repeat block from the same code blocks drawer. This is also known as making a loop. Set the repeat to the initial value of the timer.

Place the wait and change blocks inside the loop.

Our complete code so far looks like this:

It would be helpful to have a sprite on the screen tell us the time on our countdown timer.

 option in the code blocks drawer. Put the 

 code that we have just created and set it to say the value 

 so the complete code for our countdown timer with helpful sprite is now:

We also added a backdrop to inspire us! On the right hand side of the Scratch screen, there is the 

 with Scratch cat currently loaded onto it. We want to change the background that Scratch cat is currently on by hovering on the blue circle with an image logo that can be found in the bottom right of the screen. Then find the option that says 

We selected the Playing Field background.:

To make the Scratch cat look as if it is running, we changed its 

. At the top left hand side of the Scratch screen above the code blocks, select the tab named 

Making marty move while the countdown timer ticks down...

 starts and stop moving when the timer reaches zero. This means we want two things to be happening at the same time so will use 

We will use a broadcast block from the Event blocks. This block sends a broadcast message across our Scratch program and any code that starts with the when I receive block set to that particular broadcast message will be kick-started to run. These blocks are shown below:

So we need two different actions to happen at the same time:

To do this we need to run our coding blocks in parallel which means at the same time. Make a broadcast message called start.

Add the broadcast message to our existing code after get ready:


Just above where you found the broadcast block in the 

 block. This block will run when we broadcast that message. Make a 

Now it is time to code Marty’s motion. Whatever Marty is doing whether it is walking forwards, sliding sideways or any other creative way to move, we only want Marty to be doing this while the time counts down.

 that will repeat until the time is equal to 0 (zero). For this we need a 

We also need the block with the equals sign from the 

 option in the coding block drawer. This block checks if the first value is equal to the second value. If the values are equal, the 

 and then compare values again… Set this block to test if the value of the 

 is at zero, we want this script to stop running to stop Marty from moving any further. Use a 

We can now add whatever motion we want Marty to do inside the 

Here is an example of the complete code that would make Marty 

 reaches zero. We only need to tell Marty to 

 block makes one step happen again and again... and again until the 

Set up a start line for Marty and give the code that you have written so far a go!

So we have a countdown timer, a helpful sprite and we have made Marty walk forwards until the timer stops. Now we can start playing with Marty's different movements and see what effect this has on how fast Marty moves.

We can change Marty's motion using these 

 taken for these movements to happen. You might come up with other ways of making Marty move along using other code blocks!

It can be useful to know the speed of a moving object. This is an idea you might come across in Physics or Maths lessons. It also gets used in all sorts of everyday situations from sports to speed cameras!

Here are a few things you will need to think about:

 of an object can be worked out if we know the 

 that Marty has moved from the start line when the 

 that the timer counted down for then you have the information needed! You can work out 

 taken as shown by the relationship below:

 you are using the measure the distance in so you give the correct units for your speed. For example, a 

Make Marty move in different ways, record 

You might find it helpful to draw up a results table like the one shown below:

Now that you know how to work out speed, wouldn’t it be helpful if all you had to do was measure the distance travelled and then have the sprite calculate the speed for you?

Your challenge is to add blocks to the code so that, after Marty stops moving, the sprite on screen asks you for distance and time measurements and then displays the speed that Marty was travelling at.

How will the sprite ask questions and how will you enter your answers? 

The speed that is calculated needs to have the correct units. Y

ou will need to decide what units you want the distance and time answers entered in!

How will your code keep track of the information that is entered? 

Marty's Super Speed Investigation

Using Scratch 3, you will code a snowstorm then create an interactive program using the input from two bump switches attached to Marty's feet to control a penguin sprite on screen making it move with sound effects. You will extend your code to make Marty move at the same time. You can then use this code as the basis for setting up your own Marty Winter Wipeout course so get your imagination ready!

After coding a snowstorm, the input from two bump switches attached to Marty's feet is used to control a penguin sprite on screen. The sprite moves with sound effects to the right, to the left or jumps depending on the inputs received. The code is extended to make Marty move at the same time as the sprite. Marty is then ready to take on a Winter Wipeout Challenge so get ready to use your imagination!

How to use the input from bump switches to control a sprite on screen

This activity can be linked to concepts covered in the lesson packs Responding to our Environment and Programming Concepts 1 and 2.

Lesson Pack – Responding to Our Environment

You can find a helpful guide to bump switches in 

Bump Switches: Give Marty a Sense of Touch!

 This also gives you instructions for connecting bump switches to Marty. You will need two bump switches, one attached to each of Marty's feet.

Create a new Scratch 3 project with the Marty the Robot extension added.

Time to get programming! Start with a when green flag clicked 

When we connected the bump switches to Marty, the bump switch connected to Marty's right foot was connected to 

 and the bump switch connected to Marty's left foot was connected to 

. Your inputs might be different depending on how your bump switches are connected to Marty.

Towards the bottom of Marty’s scratch blocks, you’ll find an

Click the block to check the current state of the bump switch. A “1” means the bump switch is pressed, and a “0” means it is unpressed.

Set the input to 1 to check on the state of the other bump switch:

We will use these inputs later in our coding.

Oh the weather outside... Create a snowy Scene

The first thing that we have to do is create an snowy theme on the Scratch stage section of the screen.

 of the stage to be something with a snowy theme.

Now we want to add a snowstorm! We are going to clone some snowflakes...sounds like fun!

We now need to select a new sprite - a snowflake to create a snowing effect. This is very similar to changing the backdrop except we use the button beside the backdrop one and search again like before.

Change the size of your snowflake sprite by making the number in the 

 smaller. Our snowflake is set to size 25.

Before we go any further, we want to make sure that the original cat sprite (Sprite1) isn't visible! We've heard of the expression "raining cats and dogs" but we don't want it to be literally "snowing cats and dogs"... To do this you need to change the setting for the sprite so that it isn't showing or you can delete it.

Once you have added your snowflake sprite your stage should look something like this:

The screen is a 480 by 360 rectangle. The 

 can be any value from -240 (sprite as far left as possible) to 240 (sprite as far right as possible). We are going to use x values from -180 to 180 to keep the snowflake on screen.

 blocks (shown below) to randomly pick the x value where the snowflake starts and another 

 block to select the x value of the finishing point of the snowflake.

Set the values to range from -180 to 180:

 of 180 at the very top of the screen to a 

We can tell our sprite to go the start position using a 

To make it more realistic, we will also vary the time it takes each snowflake to fall using another 

 block. Set this block to vary from 2 to 5.

 block to move the snowflakes steadily to its finish position. We will use the second 

 block that we have just made to vary the time taken for the snowflake to fall from between 2 seconds to 5 seconds. We then need another random block just like the first one for final 

We want snow to keep falling so we will put these two code blocks inside a 

Just one snowflake makes for a very boring snowstorm, we need more!

 lets a sprite to make a copy of itself while the code is running. Every clone will run the same section of code but is independent of the other clones. This means that every one of our snowflakes will start and finish in a different random place on screen and take a different random time to fall.

Start by making a clone of the snowflake sprite using the 

We have set the number of repeats to 10 to make 10 snowflake sprites.

We now need to tell our newly cloned sprites what to do. Pick a 

Add the forever loop containing the snowflake code that you have made to make each clone independently run this code:

We also want the original snowflake sprite to move so add a copy of the 

: Play around with the snowflake settings to change your snowstorm! You can change the positions of the snowflakes, the time taken to fall and the number of snowflakes.

The next step is to add a penguin sprite on screen. This sprite will move in different ways depending on the bump switches pressed.

Add another new sprite - we picked a penguin! If you get stuck, look back at the "how do I add a new sprite" instructions.

Don't delete or hide the snowflake sprite!

If the bump switch on Marty's right foot is pressed, we want the penguin sprite to move away to the right as if it is avoiding an obstacle. We will get the code for the penguin "right" move ready and will link this with the Marty's right foot bump switch in the next section.

We want the penguin sprite to start in the middle of the screen, select a 

Next we will turn the penguin sprite slightly to the right using a 

 block and setting the angle to 15 degrees.

Then the penguin will move steadily down to the right on screen. For this we need a 

 block and we will set the time to be 1 second, the 

We want to add a sound effect so will use the 

Marty's winter wipeout

Using Python, you will create a program that will transform your Marty into Maryu, the Street Fighter Marty, extending it to use the attacks and taunts that you want.

The video above is an example of what you can make your Street Fighter Marty do.

A computer (additionally a monitor/TV with an HDMI cable, keyboard, and mouse to connect to the Raspberry Pi for convenience)

A Joy-Con or any other Bluetooth controller (USB controllers can be used as well!)

The beauty of executing your program via your Raspberry Pi to connect and make your Joy-Con control your Maryu

Scanning IP addresses, manually connecting a Bluetooth device to your Raspberry Pi

Configuring your Raspberry Pi to connect to a Wi-Fi network without using an HDMI cable

Transforming your polite, civil Marty into a fierce street fighter!

Before we even start the programming part of the activity, we need to set up the environment via Raspberry Pi.

First, download and install an SD Memory Card Formatter on your computer to format your SD card based on your Operating System, for example,

https://www.sdcard.org/downloads/formatter/

Download the Raspbian ZIP file for your Raspberry Pi (also simplified to Pi when referred to) via,

https://www.raspberrypi.org/downloads/raspbian/

https://www.raspberrypi.org/documentation/installation/installing-images/README.md

Following this, there are two ways of booting your Pi. Without using a HDMI cable and running it on your computer via VNC Viewer, or by using a HDMI cable with a monitor, keyboard and mouse, which would be an easier alternative.

First ensure your Pi is powered with the SD card in the SD card slot (with Rasbian installed). You will now boot your Pi for the first time without a HDMI cable!

The following video will guide you through the process of booting your Raspberry Pi,

https://www.youtube.com/watch?v=zBD7t5eWCoY

You can get the IP address of the Raspberry Pi using 

 after connecting your Pi to your Wi-Fi network as shown in the video above. Make sure your computer and Pi are connected to the same Wi-Fi network. You can ssh into your Pi via Terminal by running the command,

The default Pi password is ‘raspberry’ and the connection to your Pi can be closed using the next command,

You should now be able to connect to your Pi via 

 as shown in the previous video. When booting up the Raspberry Pi for the first time, you will be guided on connecting to your Wi-Fi network and you will be requested to update the software on your Raspberry Pi.

To make sure the packages on your Pi are up to date, ssh into your Pi via Terminal or by connecting to your Pi via the VNC Viewer, and then run the following commands via Terminal (it is the third icon to the right after the Raspberry Pi icon on the top left corner when using VNC Viewer),

$ sudo apt-get update
$ sudo apt-get upgrade

You are now set up to progress with the activity!

booting raspberry pi with a hdmi cable (easier!)

Booting your Pi for the first time with a HDMI cable is a very simple and straightforward process.

Make sure your Pi is powered with the SD card in (with 

 installed) and make sure it is connected to a monitor/TV via the HDMI cable and connect the peripherals (keyboard and mouse) via the USB ports.

The Pi should boot immediately when powered, and this will be visible when connected.

You will be guided on connecting to your Wi-Fi network and you will be requested to update the software on your Raspberry Pi. To make sure the packages on your Pi are up to date, open Terminal (it is the third icon to the right after the Raspberry Pi icon on the top left corner), and run the following commands,

$ sudo apt-get update 
$ sudo apt-get upgrade

Brilliant! You are now all set to progress with the activity!

After making sure the existing packages on the Pi are up to date, you need to check what version of python and pip is on the Pi.

 is the programming language used to do this activity and 

 is used to install and manage software packages written in Python.

We can check what version we have via Terminal by running the commands,

This should return the version installed for Python 2 and pip is used to support Python 2.

Similarly, the commands below should return the version for Python 3,

Pip should be on the Pi by default but in the case that it is not, the command below will install it,

The command below is used to compile python extension modules and 

 is used to connect Bluetooth or USB peripherals/controllers (like our Joy-Cons) to the Pi.

$ sudo apt-get install python-dev 
$ sudo apt-get install bluez

You may now choose to program the activity using Python 2 or Python 3. Python 3 is more to date/current.

The commands to install the libraries to connect and communicate with the Joy-Con (evdev) and Marty (martypy) are below.

$ sudo pip install evdev 
$ sudo pip install martypy

$ sudo pip3 install evdev 
$ sudo pip3 install martypy

A Python library is a set of pre-written code or methods that someone else has written that we can directly use! They are used a lot to save time because instead of rewriting lots of different algorithms of programs all the time, we can import these algorithms for us to immediately use!

Before programming the activity to control the Marty with the Joy-Con, it is insightful to connect the Joy-Con to the Pi and get the event code to identify the buttons that are pressed and to assign values/actions to them.

To connect the Joy-Con via Bluetooth, click on the Bluetooth icon on the top right (next to the Wi-Fi icon), turn it on and select ‘

Note: The Joy-Con will not be displayed as an option to connect to because you need to press and hold the tiny silicone button next to the lights on the side until the lights start flashing.

The Joy-Con should then appear as an option to connect to. Select it and there should then be a green tick next to Joy-Con.

If the Joy-Con fails to be connected to the Pi, you can manually trust, pair and connect to the Joy-Con by running the following sequence of commands,

(XX:XX:XX:XX:XX:XX is the device ID in hexadecimal)

Monitoring connectivity of Bluetooth devices can be seen once running the command below.

This can be down in a separate Terminal Window/Tab whilst connecting the Joy-Con manually (if preferred)

Now your Joy-Con is connected to the Pi, the following commands display the event codes and values to identify which buttons are pressed on the Joy-Con, for Python 2 and Python 3, respectively,

$ python /usr/local/lib/python2.7/dist-packages/evdev/evtest.py 
$ python3 /usr/local/lib/python3.7/dist-packages/evdev/evtest.py

Knowing the number the Joy-Con is referred to by is important for the Python script that we will be coding and running in a bit!

https://core-electronics.com.au/tutorials/using-usb-and-bluetooth-controllers-with-python.html

Your Joy-Con may disconnect when not in use, simply press and hold the tiny silicone button next to the lights on the side until the lights start flashing and then try re-connecting to it.

Before you run the command via terminal to download the files to control Marty, first make sure you are in the right directory!

To check which directory you are currently in, run the command below,

It should return and display names of folders.

Desktop should be among the names and we recommend downloading the file when you are in the Desktop directory.

Changing to the Desktop directory can be done by running the command below,

The files to control Marty can then be downloaded via the following command,

You will see the folder on the home screen once you have run the command.

If you want to go back to your previous directory, then run the following command,

Since you can now connect your Joy-Con to the Pi and connect your Marty to the Pi, we are going to focus on the Marty being controlled by the Joy-Con via the Pi.

We already know the event codes for the Joy-Con buttons and we know what event number the Joy-Con is to manually make it communicate with Marty. This was done in the 

Information on API referencing for the Joy-Con events can be accessed,

https://python-evdev.readthedocs.io/en/latest/apidoc.html

There are examples on how event codes and event values can be used to identify button/key pressed and actions can be assigned when the buttons/keys are pressed.

Maryu, the Street fighter marty

If you have you been trying to outlast Marty in the Marty workout or just need a moment of calm, you need this Mindful Marty activity! You will do some mindful breathing with Marty and then follow Marty through a series of robot yoga poses. Bliss!

This activity guides you through how to write all the code needed for a calming mindful breathing and robot yoga routine. Once programmed, Marty will be your instructor so that you can follow along either alone or sharing the relaxation with others!

This activity is linked to the contents of lesson packs Programming Concepts 1 and 2.

It also offers the opportunity for cross-circular health and wellbeing work.

Before we get started coding, we need to adjust how high Marty's arms can go. You will need a screwdriver like the small screwdriver that you used to assemble Marty for this.

Learning Portal

Marty's Super Speed Investigation

Marty's winter wipeout

Maryu, the Street fighter marty

Mindful marty

Shaking hands with Marty

Teach Marty to Walk

The Marty Bell Orchestra

Winter Olympics: Skiing Marty

Workout with Marty!