Lesson video

Hello, my name is Mr. Hogan.

I'm so excited to be learning with you today.

You've made a great choice to learn about physical computing and the micro:bit with me.

We're can have such a great time learning together.

I'll be supporting you along the way with your learning during these lessons.

I'm so pleased that you've decided to complete your learning with me today.

We are going to do brilliantly.

Good luck.

Welcome to today's lesson from the unit, "Physical computing using the micro:bit." This lesson is called "Connecting micro:bits to other hardware." I'm really looking forward to this lesson.

It can be challenging in some parts.

But please, you can pause the video or rewind the video to go over parts if you didn't understand that particular slide.

It's gonna be a really good lesson.

I'm looking forward to it.

So keywords from today's lesson.

GPIO pin, this is a general purpose input/output pin.

It's a programmable pin found on microcontrollers and other digital devices.

Ccircuit, a complete path that electricity can travel through.

For example, a loop that lets electric current flow.

And the last key word is wireless, which is the transmission of data between devices without using physical cables or wires.

Today's lesson is split into two different parts.

The first part is all about writing programmes for external hardware using the GPIO pins.

And the second part is exploring the radio module for wireless messaging.

So hopefully, it's gonna be a fantastic lesson.

Let's start with "Writing programmes for external hardware With the GPIO pins." The micro:bit can be connected to other external hardware Through the GPIO pins.

This will become part of a circuit.

Remember, GPIO means general purpose input and output.

Some tasks in this lesson require wires and an LED.

But you can use the emulator if you don't have them.

So you haven't got the physical wires or the LED, the emulator on them micro:bits make code programming environment will let you simulate what would happen.

The GPIO pins let your programmes control the power in a circuit, which is like an output, and detect power in a circuit, which is like the input.

This circuit will not work because the circuit is not closed.

The wires are not touching each other, if you can see.

So they do not form a complete loop.

So you can see the crocodile clips on the left hand side of the circuit.

They're not touching.

So the LED, like Aisha is saying, is not working.

To close the circuit, tin foil has been used to create a connection between the two crocodile clips.

So once that circuit is closed by the tin foil, as Alex is saying and is shown in the diagram, the LED is now on.

This programme will show a smiley face icon when the circuit is closed.

So you can see that we are referring to pin 0.

So when pin 0 is pressed, then the smiley face will appear.

Else, the unhappy face will appear.

You can use these blocks in the micro:bit MakeCode editor.

And if you can, transfer it to your own micro:bit.

If you have a micro:bit, close the circuit by pressing down on GPIO pin 0 and the GND pin, known as the ground pin.

So if you get your micro:bit and literally put your fingers on there, you should be able to see the smiley face appearing because the circuit is closed.

You can recreate this as well using the emulator.

Aisha's saying, "When I touch the pins, the circuit is closed and the smiley face icon appears." That's correct.

Alex is saying, "Yes, A tiny safe amount of electricity flows through your body.

It is similar to closing a circuit using the tin foil." So our body is actually conducting the electricity from GPIO zero to the ground pin.

Let's have a quick check.

How can a micro:bit be connected to external hardware? Is it A, through the USB cable, B, using the speaker, C, by pressing on the logo, or D, through the GPIO pins.

Have a think.

You can rewind the video any time and pause it.

The answer is D, through the GPIO pins.

Well done if you got that correct.

We're now gonna set up the hardware on our micro:bit.

So we're gonna connect a wire to the power pin, the 3V pin, and then connect another wire to one of the input pins.

In this image, the pin 1 is used as the input pin.

But you can also use pin 0 or two.

Now, any contact between these wires will allow the circuit to be formed.

The digital right pin block turns the voltage of the pin on or off.

In this programme when button A is pressed, pin 0 turns on and number one shows on the LED display.

When button A is not pressed, pin 0 turns off and number zero shows on the LED display.

So we've not used number one as the pin in this example.

We've used pin 0.

So this example, the LED also lights up when this programme is run and button A is pressed.

So now, you can see that we're using pin 0 as the input pin, not pin 1.

And you can see the representation of the LED lighting up and the number one appearing on the LED screen when button A is being pressed.

Well done on getting this far.

Remember, you can pause the video at any time.

It is a lot to take in.

But it's really exciting.

We are now attaching external hardware.

LEDs are not the only external hardware that can be used with a micro:bit.

A buzzer can be connected to make a noise when a circuit is closed, or a motor can be connected to turn a device, like a fan, on or off.

Let's have a quick check.

What is the main purpose of the digital write pin block? Is it A, it turns the voltage of A GPIO pin on or off, B, it reads the button press, C, it displays a number on the LED display, D, it measures the temperature? Have a think.

Remember, you can rewind the video or you can pause it, and have a think about the answer.

So the answer is A, it turns the voltage of a GPIO pin on or off.

Let's move on to task A.

So number one is to use this link to go to the micro:bit MakeCode programming environment.

Create a programme that will display, "This is a triangle," followed by the triangle icon if there is a closed circuit using pin 2.

If there is not a closed circuit, display, "This is a square," followed by the square icon.

If you can, transfer the programme to your micro:bit, connect the battery pack, remove the USB cable, and test the programme by closing the circuit on your micro:bit.

Remember, you can rewind the video at any time to see how you can set this up, and look at the programme blocks as well.

Or have a pause and go to the MakeCode website, and have a good doing this programme.

Well done on getting this far, that's great.

Hopefully, you a really good time.

creating your programme.

This is just one solution.

Yours may vary slightly.

But you can see that I've put here, if pin 2 is pressed then show string "This is a triangle," then show the icon triangle.

And that's what we're asked to do.

And then else show string "This is a square," followed by the square icon.

So this is the probably one of the most straightforward ways of doing it.

But hopefully, you have good fun trying.

Well done.

Number three, create a programme that will display, "Hold down button B to start." When button B is pressed, "Welcome to the micro:bit" is displayed.

And an LED attached to pin 3 and the GND turned on and lights up.

If you can, transfer the programme to your micro:bit, connect the battery pack, remove the USB cable and test the programme by closing the circuit on your micro:bit.

Remember, pause the video.

We can rewind it at any time.

Hopefully, you go and have some fun trying to create this programme.

Well done.

Hopefully, you had fun trying to create this programme.

This is just one solution.

So we've got a forever block with an if saying button B is pressed, then digital right pin 3 to 1, so turn it on, and show string "Welcome to the micro:bit." Else, show string "Hold down button B to start." Remember, this is just one solution.

And well done just for even having a go at trying to create this programme.

Well done on completing the first part of the lesson.

Some really new complex and challenging ideas.

Hopefully, you've learned a lot.

And we're gonna move to the second part of the lesson, which is all about exploring the radio module for wireless messaging.

It's gonna be fun.

And hopefully, remember, you can rewind and pause the video at any time.

Lots of devices are connected to each other without using wires.

Aisha's saying, "My headset connects to my phone wirelessly." And Alex is saying, "The CCTV cameras in school connect wirelessly to the wifi." Can you think of any other wireless devices you've come across in everyday life? Micro:bits have a built-in component for wireless communication over radio.

They can broadcast and receive messages.

Aisha's saying, "My headset uses a Bluetooth connection, which also uses radio." That's correct, Aisha.

If you have a headset, most likely it uses Bluetooth, which then in turn uses radio to communicate data between devices, such as your phone to your headphones, or tablet to your headphones.

So yeah, it's used in everyday life.

Let's have a quick check.

What device can use radio to transfer data? Is it A, a USB flash drive, B, a speaker playing music, or C, a wired computer mouse? Remember, you can pause the video any time or rewind it.

Should we have a look at the answer? It is B, a speaker playing music.

So a speaker can be wirelessly connected via Bluetooth to another device, like your phone.

So yeah, it is transferring.

And it's using radio to transfer that data, that music.

The radio set group block allows you to create separate communication channels between micro:bits.

This ensures that messages intended for one group of micro:bits do not interfere with messages for another group of micro:bits.

So you may only communicate to other micro:bits that set their radio group to the same number as what your micro:bit is set to.

The radio sends string block, sends a message to all micro:bits in the same group.

So you can see the blocks here on the right where we've got on button A pressed, radio send string 'hello', and then pause for 1,000 milliseconds.

The radio received block is used to handle messages sent by the other micro:bits in the same group.

The message is typically assigned to the default variable receivedString for further use in your programme.

So you can see the blocks on the right where we have got the receivedString defaults as a variable name.

And then we say show string receivedString.

Let's have a quick check.

What's the main purpose of the set radio group block? Is it A, to allow micro:bits to send messages only to other micro:bits in the same group, B, to increase the speed of the radio signal, C, to display a message on the micro:bit's screen? Remember, have a think about it, pause the video.

The answer is A, to allow micro:bits to send messages only to other micro:bits in that same group.

So we don't have this confusion of two micro:bits sending messages to different groups.

The radio set group, radio send string, and the radio received blocks can be used with other blocks to programme the micro:bit.

These are all found in the radio group.

In this example, when button A is pressed, another micro:bit will appear and "Hello" will appear on the display.

So you can see in this animation where button A is being pressed and the micro:bit appearing with hello appearing.

So you can see in this animation button A is being pressed and "Hello" is appearing on another micro:bit.

And you can see on the blocks on the right hand side where we set the group to zero, We said radio send string to 'Hello', and then pause for a 1,000 milliseconds when button an A is pressed.

And then we've got the on radio received show string radio, so show string receivedString.

Aisha's saying, "If we both create these blocks, we should be able to send the message 'Hello' to each other." Alex says, "Great!" So yeah, these are the blocks that we need to use in the programme, so that we can send each other a message, in this case, "Hello." You're doing really well.

Hopefully, you're understanding these new blocks that we're gonna use, these radio blocks.

Remember, you can pause the video at any time or rewind it.

But it's really good.

It's so exciting that you're learning how to use radio on the micro:bit.

The first practise is to connect your micro:bit, again, to your computer if you have one.

Number two, create blocks that will, A, set a radio group to three.

Or if you are working in a small group, decide on a channel number you will all use.

B, when buttons A and B are pressed, create and send the message "This is [name]." Obviously, we replace the word name with your own name.

C, when a message is received, the micro:bit shows the string.

Remember, you can pause the video and rewind the video to look at blocks that we've previously looked at at any time.

So let's have a look at the answer.

Here, we've got blocks that set the radio group to three.

So an on start block with the radio set group to 3 block.

B, we've said here on button A and B pressed, radio send string "This is Alex." Alex, obviously, has replaced the name.

And then pause for 1,000 milliseconds.

And then we've got the C part, which is on radio received block receiveString show string receivedString variable.

Three, use the emulator to test your programme.

So remember, you can go into the micro:bit MakeCode environment and test your code.

Remember, you can pause at any time, or rewind the video to see how we did it previously.

So it should look something like this.

If you have coded your programme correctly where this additional micro:bit appears, once the A and B buttons are pressed, which is represented by A and B on the bottom right of the image of the micro:bit, and then the name Alex will appear.

Well done, I hope you're having really good fun trying these out.

So number four, if you can complete this, do the following tests.

But you'll need two micro:bits.

Transfer the programme to one of your micro:bits.

So I'm gonna put the programme onto this micro:bit, okay? And B, remove the USB cable.

So I've done that.

Then transfer the programme to a different micro:bit.

So I'm gonna do that for this one.

And I've also connected then the battery pack to it and remove the USB cable.

Okay, so the idea is to move one micro:bit to the other micro:bit.

So this one could be still connected.

But I've actually got a battery pack on it, so they're close together.

Then on one of the micro:bits, press button A and B at the same time.

So I have just one of them.

Press A and B at the same time.

So the idea is to get your programme on two micro:bits.

Hopefully, you've got a at least one battery pack.

And then move it closer to the other one.

And then press buttons A and B.

So then, hopefully, you'll find that Alex, the string Alex will appear on the micro:bit that you didn't press buttons A and B together on.

Hopefully, that's worked.

Well done if it did.

Five, imagine you have two micro:bits.

Describe a project you could create using the radio feature.

Remember, you can pause at any time or rewind the video.

So let's have a look at some answers for number five.

So the question was, "Imagine you have two micro:bits.

Describe a project you could create using the radio feature." So I could create a secret yes/no game of two micro:bits.

I could ask someone a simple yes/no question.

And they could secretly answer using their micro:bit, yeah? If they press button A, the micro:bit would show yes on the LED display.

If they press button B, the micro:bit would show no.

Yeah, so A for yes, B for no.

And that would be secretly then messaged back.

No one around you would know the answer.

It would be like having your own private communication system.

Yeah, that's a great answer.

But hopefully, you've come up with others that are equally as amazing.

Well done.

well done, it's the end of this lesson.

You've done really well to get this far, understood lots of different things about the micro:bit and using it with other hardware, and using the radio on it, amazing.

So in summary, you can connect external components, like LEDs, buzzers, and motors to the micro:bit to give it new functionality.

The micro:bit's GPIO pins allow you to control external components with code.

You can write a programme to make an LED flash.

The micro:bit can send and receive messages wirelessly to other micro:bits.

This lets you create projects where devices communicate with each other, like a wireless game controller or a secret messaging system.

There's lots to take in in this lesson, so well done.

I hope you really enjoyed it.