Lesson video

Hello, my name is Mr. Hogan.

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

You have made a great choice to learn about physical computing.

I'm so excited about this lesson.

We're gonna have such a great time learning together, and I'll be here helping you with our learning during these lessons.

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

We are gonna do brilliantly welcome to today's lesson from the unit physical computing using the micro:bit.

This lesson is called "Using Input and Output," and you'll be learning to write programmes that use the output and input features of a physical computing device.

I'm really looking forward to learning with you today.

And remember, you can pause the video or rewind the video at any time if you want to get over some points.

Keywords for today's lesson.

We've got light emitting diode, often referred to as LEDs.

This is a component that emits light when electricity flows through it.

The next one is hardware component.

So this is a physical part of a computer or device that helps perform its function, such as wires, buttons, or an LED display.

Then we have a sensor.

This is a device that can detect things like light, temperature, or movement.

This lesson is split into two parts.

The first one, we're going to explore the LED on the micro:bit, and the second part is we're going to use sensors to create our own interactive programmes.

Parts of this lesson you might find challenging, but don't worry.

We all find things hard when we first do things, so please try your hardest, and I'm sure we'll enjoy the lesson and get through it together and really have successful outcomes at the end.

Let's have a look at the first part of the lesson, which is where we're going to explore an LED display using a micro:bit.

So the LED display is shown here, and we've lit it up using the heart icon, so it displays the shape of a heart which is filled with red LEDs.

So it's a five-by-five ED display.

So there's five LEDs along the top and then five LEDs along the side.

So that gives us 25 LEDs.

And we can also attach additional output devices through the general purpose input and output pins or known as GPIO pins.

These are at the bottom of the micro:bit.

Lucas is saying, "I saw an LED display on the front of a bus showing the number and the destination." Izzy is saying, "Yes, these LED displays use software that is programmed to control which LEDs light up to show numbers and text." Lucas has also seen LEDs.

He's saying, "I have also seen LED displays at bus stops, train stations, and on motorway signs." Have you seen any LED displays anywhere? Just like the LED displays used on buses at bus stops and at train stations, we can display text, numbers, and icons on the micro:bit's LED display.

These blocks are used to display the heart image on the LED display.

So at the beginning of the lesson where we saw the heart icon on the micro:bit, this is how we programme the micro:bit to do this.

So you use the on start block, and then use the show icon block, and then make sure it's the heart icon.

The LED display has preset icons that can be used by selecting the dropdown arrow here.

So there's lots of different preset icons that you can use.

smiley faces, and happy faces, alien faces, crosses, ticks, lots of preset icons that you can use.

Let's have a quick check.

How many LEDs are there on a micro:bit? Is it A, five, B, 10, C, 15, or D, 25? Have a think.

You may rewind the video anytime or pause it.

Should we have a look at the answer? How many LEDs are there on a micro:bit? The answer is 25.

Yes, so we have five LEDs along the top, five LEDs down the side.

So if you multiply them together, it's 25.

Well done again this far.

Hopefully you've enjoyed the lesson, and now we're gonna actually use these 25 LEDs on a micro:bit.

This programme uses the forever, if button is pressed, show icon, and pause blocks.

Depending on which button the user presses, an icon will be displayed for a hundred milliseconds, which is 1/10 of a second.

So take your time and look at these blocks and see if you can understand what's going to happen when button A or button B is pressed.

So when button A is pressed, a tick will appear, and a smiley face after a pause of 100 millisecond.

And if button B is pressed, a cross or an X will appear, pause for a hundred milliseconds, and then an unhappy face will appear.

Izzy is saying here, "I want to light up specific LEDs to get someone's attention, but there isn't a preset icon I can use." Lucas has added, "You can switch the individual LEDs on or off using the squares on the show LED block." Yeah, so there is a show LED block where you can click on separate LEDs to create your own patterns.

This programme uses the show LEDs block and the pause block together.

When buttons A and B are pressed.

When they're pressed at the same time together, specific LEDs light up.

The programme then pauses for 100 milliseconds before the other LEDs light up.

So you can see on the programme that the corner LEDs light up first, and then the LEDs in the middle of the edges of the display then light up.

Take your time to look at the programme.

You're doing really well to get this far in trying to understand how we're gonna use all these LEDs on the micro:bit.

Let's have a quick check.

This programme uses the repeat and clear screen block.

Can you predict what will happen? Will A happen, the LED display will repeat times showing a large cross pattern and a blank screen, each for 500 milliseconds? Or will B happen, the LED display will show the diamond-like pattern continuously for 10 seconds? Or will C happen, the LED display will flash random patterns for 500 milliseconds each, repeating 10 times? So take your time, look at the blocks, look at the programme.

See if you can work out what's going on.

Remember you can pause your video at any time or rewind it and have a think about the answer.

Right, Let's have a look at the answer.

It is A, the LED display will repeat 10 times showing a large cross pattern and a blank screen, each for 500 milliseconds.

So it'll be like that pattern flashing on and off the micro:bit LED display.

So now it's time to connect your micro:bit to your computer if you have one.

This is our first practise.

So task A, one, how long are the pauses in this programme? So take a look at that programme.

And then two, the ghost and skull icons along with the repeat block are used in the programme.

Describe what will be displayed on the LED display of the micro:bit.

So take your time in answering these two questions.

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

Shall we have a look at the answer? So, one, how long are the pauses in this programme? One second because the pause is set to 1,000 milliseconds, so that is one second of time.

Two, the ghost and skull icons along with a repeat block are used in the programme.

Describe what will be displayed on the LED display of the micro:bit.

So the answer to this one is, and hopefully you recognise the answer, but don't worry if you didn't.

The LED display of the micro:bit will repeat between a ghost icon and a skull icon six times, each displayed for one second.

So don't worry if you've got the words of the skull icon and the ghost icon correct, but if you've got the idea of it repeating, that's amazing.

Well done.

Number three, create a programme on the micro:bit that responds to the button presses as follows.

A, when one button is pressed, all the LEDs should light up, pause, display a cross icon, pause, and repeat this four times.

B, when a different button is pressed, all the LED should light up, pause, display a downward-facing arrow icon, pause, and repeat this sequence four times.

So take your time thinking about these.

You may want to reread these questions and go to the micro:bit programming environment to programme it.

Remember you can pause this at any time or rewind it to refresh your memory at any parts of the lesson.

Should we have a look at the answer? So three A asked, when you one button is pressed, all the NED should light up, pause, display a cross icon, pause, and repeat this sequence four times.

You may have slightly different answers, but this is the solution I came up with.

So I've got the forever block and an if block saying if button A is pressed, and then repeat four times, all the LEDs lighting up, pause of 500 milliseconds.

Then the cross icon appear, pause for 500 milliseconds, and then that repeats another three times, making it four in total.

B, when a different button is pressed, all the LED should light up, pause, display a downward-facing arrow, pause, and repeat the sequence four times.

So what I did was did a little trick on the micro:bit programming environment, and right clicked and duplicated some icons, and then I just changed the show icon to a downward-facing arrow.

I also changed the button being pressed 'cause it asked us to use a different button, so I use button B, and that's what I changed so I did it quite quickly.

You may have a different solution.

You may have put some blocks under other blocks in the repeat block.

That's fine.

So yeah really well for getting this far.

And hopefully if I get go at programming, the LED display on the micro:bit.

Well done.

The if block may also be used under the previous if block within the same forever block.

Excellent for getting this far in the lesson.

We're gonna move on to the second part of the lesson, which is using sensors to create interactive programmes.

So we're gonna use all the sensors on the micro:bit.

There's lots of them.

Built-in hardware components and sensors on the micro:bit include an accelerometer, a light sensor, a temperature sensor, and buttons.

And we're gonna use these, and you're gonna explore them, and use them throughout this rest of the lesson.

It's gonna be really exciting.

Aisha's asking, "Have you ever noticed how a phone or tablets screen flips when you turn it sideways? That's an accelerometer.

It senses how you are tilting the device." Alex is saying, "In some racing games, when you tilt a device to steer, that's an X accelerometer measuring the movement." So these sensors are all around us and we actually use them in everyday life, maybe without even knowing.

So learning to programme an accelerometer helps you understand how devices use these sensors.

You can use your imagination to come up with new and exciting ways to use the accelerometer.

This programme displays a happy face whenever the accelerometer detects that the micro:bit is lying face up.

So we've got the forever block and if block with is screen up gesture, then we're gonna show the smiley face.

If it's not so, else, we're gonna clear the screen.

This programme displays a left arrow when the accelerometer detects that the micro:bit is tilting to the left.

So have a look at these blocks.

Hopefully you're understanding what they do on the micro:bits and how they control the LEDs.

Aisha is saying, "I like the idea of using a micro:bit's accelerometer, but it's attached to my computer with A USB cable, so it's difficult to move around." The micro:bit can be powered by two AAA batteries, using a battery pack.

When the battery pack is connected and the USB cable is removed, the micro:bit will still work.

So as long as you transferred the programme to the micro:bit, then you can attach the battery pack, remove the USB cable, it will still work.

So if you've programmed it to do those different arrows, that will still work on the micro:bit.

So you can actually take it away from the computer.

Let's have a quick check.

Which of the following is used to detect movement of the micro:bit? Is it A, the accelerometer, B, light sensor, C, temperature sensor? Remember you can pause the video at any time or rewind it to have a think.

Should we have a look at the answer? It is A, accelerometer.

Well done if you got it right, but don't worry if you got it wrong.

You can always go back and look at the slides again and rewind the video.

The micro:bit has a temperature sensor and a light sensor.

What can you make that would use these sensors? Alex is saying, "I could make a thermometer that shows me the temperature or a nightlight that turns on when it gets dark." Yes you can.

You can programme the micro:bit to do this.

This programme displays the temperature on the LED display when button A is pressed.

This will be a number in degrees Celsius.

The five by five LED matrix is not only in an output device, but it can also be used as an input device when it's detecting light levels.

The light level senses the amount of light falling onto the display.

These blocks will show the light level value of the LED display.

This programme displays the light level when the light level is less than 100.

This will be a number between zero, which is not light, and 255, which represents the brightest light the micro:bit can measure.

So take a look at these blocks, and if it's below 100, it will display the light level as a number.

Should we have a quick check? What is a possible project to programme on a micro:bit? Is it A, when the light is below 100 and the temperature is below 20 degrees Celsius, flash an icon on the LEDs; When the humidity is below 100 and the temperature is below 20 degrees Celsius, flash an icon on the LEDs; or is it C, when the micro:bit is in a specific location, flash an icon on the LEDs? Have a think about it.

Remember you can pause and rewind the video anytime Shall we have a look at the answer? So it is A.

When the light is below 100 and the temperature is below 20 degrees Celsius, flash an icon on the LEDs.

That's because we can sense the temperature, the temperature sensor, so below 20 degrees, and we can also sense light.

Well done for getting this far in the lesson, we're gonna move on to the practise now.

So task B one, create a programme that will display a left arrow when the micro:bit is tilted to the left and a right arrow when the micro:bit is tilted to the right.

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

Remember you can pause the video at any time or go back and rewind the video.

So hopefully now you can go and create this programme.

Let's have a look at a possible solution.

This is the way I've come up with it, but you may have got something slightly different.

So I asked you to create a programme that will display a left arrow when the micro:bit is tilted to the left and a right arrow when the micro:bit is tilted to the right.

So we've got a forever block here, and we've got if is tilted to the left, do the left icon, display the left icon, and then if it's tilted to the right, display the right icon on the LED display.

Well done for trying to get it right.

You may have come up slightly different things, different blocks.

You may have done two different blocks rather than one big block with a forever block around each block.

That's fine as long as you've got the outcome on the LED display.

When you tilt to the left, a left arrow appears.

When you tilts to the right, A right arrow appears.

So well done.

Two, create a programme that will light up all the LEDs on the display if the light level is less than 100 when button B is pressed.

Again, if you can, transfer the programme to your micro:bit and test it if it works.

Have a little think.

We touched upon this a few slides ago, so you may want to rewind the video and take a look at something very similar.

Well, pause the video and have a go at programming this.

So let's have a look at a possible answer.

So I've got here when button B is pressed and if the light level is below 100, then display all the LEDs.

So I've got a show LED block there with all the LEDs lit up.

Well done for getting the answer correct, and well done for having a go at it if you've got something slightly different.

Three, create a programme that will display a smiley face icon for five seconds if the temperature is over 20 degrees Celsius when button A is pressed.

If you can, transfer the programme again to your micro:bit and test it if it works.

So again, you can pause the programme and go back and see what examples we've looked at previously.

And hopefully, you can go away and programme this.

Let's have a look at a possible answer.

So these blocks here I've got the on button A pressed.

If the temperature is greater than 20, show the smiley face icon.

Pause for 5,000 milliseconds, which is five seconds, and then clear the screen.

And you may have tested it on your physical micro:bit by actually holding the micro:bit together in your hands to maybe get a temperature above 20 degrees if you are in an environment where it's below 20 degrees normally.

So well done for having a go at that, and hopefully you would've got the complete solution, may have done it slightly differently, using slightly different blocks, maybe on button B block, rather than on button A.

That's all good, all fine.

So well done for making it this far.

Four, based on what you've learned about the micro:bit's LEDs and sensors describe an idea for a project you can make.

The project should use the LEDs display and at least one sensor.

So take your time and think about, okay, you know about these sensors, you know about the LEDs displays.

Could you create your own project using these? If you want some ideas and you want to rewind the video anytime, you can do.

Take some time to think about this answer.

Should we have a look at the answer? So the question was, based on what you've learned about the micro:bit's LED's and sensors, describe an idea for a project you could make.

So when button A is pressed, the micro:bits should display a sun icon on the LED display if the temperature is over 20 degrees celsius.

When button B is pressed, the micro:bit should display a sun icon if the light level is over 100.

When tilted to the left, a right arrow should appear.

When tilted to the right, a left arrow should appear, and that's great.

And you can do all of those things at the same time on the micro:bit in different blocks.

So if you've got something similar or you had something like if button A and B is pressed, something happens, fantastic.

And see if you can put together some ideas to come up of not just one thing it can do, but a variety of different things, based on an input, something outputs.

Well done on getting this far.

So it's the end of the lesson.

Well done.

I had a really good time teaching you all about the micro:bit and using all the inputs and outputs.

So in summary, the micro:bit's LED display can be programmed to display text and images.

These LEDs can be triggered using one of the micro:bit's input devices.

Sensors can be used in programmes on the micro:bit to carry out actions.

For example, the light sensor can be used to turn on the LED display when the light levels are low.

Really well done and some of it may be really challenging to you.

I'm really pleased that you got this far and hopefully you've enjoyed the lesson.