Lesson video

Hi, my name's Mr. Brown.

Welcome to today's lesson.

We're looking at input and output design decisions.

So we're thinking about all the different inputs and outputs of our systems and how we decide what we're going to do, and thinking about how it's going to be implemented within our designs.

Now, designers make design decisions all the time, so we're gonna be thinking about how to do this and the best choices that we can possibly make.

Right, without further ado, we'll go on and look at the key learning outcomes and the key learning points and the lesson cycle.

So today's outcome is to choose the inputs and outputs for my micro:bit alarm system.

The keywords today, onboard components.

So that's different parts of a product that are already built into the micro:bit.

And offboard components, those are the different parts of a product that can be attached to a micro:bit.

The accelerometer, that's a device that measures how quickly something is speeding up or slowing down.

And design decisions.

Choices that are made when creating a product.

There are three learning cycles today.

So the first learning cycle is about alarm inputs, second, alarm outputs, and then design decisions.

Let's start with learning cycle one, alarm inputs.

So Class Six are thinking about inputs that they can use for a museum alarm that's linked to their micro:bit.

And they're thinking about the offboard components that could be attached to a micro:bit.

And those would include push-to-make switches, which could be used as a pressure alarm, for example, where within their alarm system, within their museum shoebox.

Could also use photoresistors.

Now that, they measure light.

And if people got too close, then the light levels would change.

It might create a shadow and so therefore that could be a form of input.

These are the offboard components, but they're also thinking about the onboard components.

The onboard components that are within the micro:bit and could also be used as inputs.

So there is a microphone, so it could be, if there's sound levels change, then that would sense something and then that would create a signal.

We've got light sensors, so the light sensors on the LED screens, that would change.

And if light levels change, just like with a photoresistor, then that could create a signal.

Now, Andeep has said that actually light and sound levels in his museum often change, so he's probably not going to choose those.

Let's go through the first key check for understanding.

So how can LEDs in a micro:bit be used as a sensor in an alarm? Is it A, they can measure changes in light levels.

B, they can measure changes in sound levels.

C, they can measure changes in magnetic fields.

Or D, they can measure changes in temperature.

Is it A, B, C, or D? That's right, well done.

It's A.

So LEDs can actually measure changes in light levels.

Tends to be the first five in the top row of the LEDs that are used as a light sensor.

So Class Six thought about other onboard micro:bit components that could be used as inputs.

And this is on the back of the micro:bit this time.

So there's a temperature sensor.

So if the temperature changes, then that could create an alarm.

Or the compass.

Now this could signal an alarm if a magnetic fields change or it's moved.

Now the compass is a really interesting piece of technology on the micro:bit and we're gonna be talking about that in a moment.

But it includes an accelerometer and it also includes a compass and it also includes a sensor for the magnetic fields.

Andeep is talking about how temperature levels often change in his museums. So again, he might not be choosing to use the temperature one.

He has chosen to use the accelerometer as an input for his museum alarm.

Now that's part of this little button here on the bottom left of the micro:bit.

And that's the accelerometer.

Also includes the compass and also includes the magnetic field monitor as well.

Now he says that this onboard input can sense movement and signal an alarm when it's moved.

So with the micro:bit with an accelerometer, if it's picked up, if it's moved, if it's jolted, then it will create a signal to say that it's being moved.

And that is how it could be used as part of an alarm.

So well done, Andeep.

It was a really good idea.

Let's go through another check for understanding.

Where is the accelerometer? Is it A, B, or C? Well done, it's A.

Now Sofia, she's chosen to use something different.

So she's chosen to use an offboard push-to-make switch as her input for the alarm system that she's going to be creating.

And it looks a bit like that.

And how, what she's going to do is she's going to connect the push-to-make switch to the micro:bit.

She's gonna put that push-to-make switch near the artefact.

And then if the switch is connected, so if it's been pushed and the actual, the system is connected, then the LEDs are gonna display a flashing X as the alarm.

And this will continue until it's reset as button A is pressed.

So she's thought about a lot of detail here, not just the input, but also the output.

Now other members of Class Six chose different inputs to use within their museum alarms. So Lucas is gonna use the micro:bit LEDs as a light sensor.

Jacob is gonna use the temperature sensor.

And Laura is going to use an offboard photoresistor.

Now Lucas and Laura, their's are fairly similar, 'cause they're gonna be measuring the light levels.

And Jacob's gonna be using a temperature sensor to signal if heat is detected.

Now what you've probably realised is that Lucas, Jacob, Laura, Andeep, they've all thought of different types of inputs to use and that's fine.

There's lots of different choices that we can actually have.

And that is part of the design decisions that we're going to be having to make today is thinking about which one's gonna work for you, which one's going to work for your design.

Which leads us quite nicely onto the actual tasks.

So what we'd like you to do is to discuss with a partner the inputs that are gonna work well for your shoebox museum alarm.

If you remember, Andeep went through all of the different inputs and said, "That's not gonna work for me.

That's not gonna work for me.

This one is going to work for me." What you've got to do now is decide what input is going to work well for you.

And talking about it with someone really helps.

So talk about it with a partner about the inputs that are gonna work well for you.

So you need to think about is it going to be an offboard component or an onboard component? And also how is the input actually going to signal the alarm? So you've got to think about how, what input you're gonna use, but also how is that going to actually signal the alarm? Okay, time for you to go off and have a short discussion now with a partner which inputs are gonna work well for you.

Right, Jun and Aisha discuss which inputs they're gonna use and they thought about if the input's gonna be onboard, offboard, and how the input's gonna signal the alarm.

And Aisha said, "Well, I'm gonna use the micro:bit LEDs as a light sensor next to the artefact to signal the alarm if light levels change.

And Jun, well, he's gonna use an offboard push-to-make switch next to the artefact and that's going to signal the alarm when pressed.

So they've both come up with different ideas.

I'm sure you've come up with different ideas and that's what we want.

We want lots of different ideas.

We want you all to think about what's gonna work well for your museum, for your ideas, for your decisions that you are going to be making.

Right, good.

So we've thought about the alarm inputs.

We now know what we're going to be doing.

So we move on to lesson cycle two.

So we're gonna start thinking about the alarm outputs.

So Class Six have carried on thinking, they've done their thinking about the inputs and they're now thinking about the outputs.

And we're gonna be thinking about the offboard components that we could add.

So you could add a buzzer or you could use a bulb.

These are just two examples.

There are lots of other examples that you could actually use.

There's also onboard components that could be used on the micro:bit as outputs.

So the LEDs, they signal a message or a picture.

And we can also think about whether we, where we're going to actually put those.

So, Andeep's saying, "Well, actually I need to think about where to put the micro:bit so the alarm can be seen." 'Cause again, it's all very well and good choosing this as an output.

It's a really good output.

But actually where's it going to go? Where's it gonna be most effective? But there's other onboard components on the back and that's the speaker.

Now you can create a message on there.

You can signal a sound to come on, you can signal an alarm, you can change the pitch.

There's so many different things you can do with the speaker.

And Andeep's put down, well, he needs to code an input like an accelerometer with any output and he can do that in Tinkercad.

So one of the things that he's got to do when he's choosing which output is actually think about how the input is going to affect that output.

And this is the tricky bit now.

You've chosen an input, you've now got to choose an output that's going to work well with it.

You might want to change your ideas for the input and that's absolutely fine, but we've got to now start thinking and making decisions.

Is it gonna be, what's the input gonna be? What's the output going to be? Check for understanding.

How can LEDs be used as an output in an alarm? Can they display a picture? Can they play a recorded message? Can they display a message or can they make a sound? I'll give you a bit of a clue here.

There are two correct answers.

Okay, off you go.

Right, well done.

It's A and C.

So the LEDs can display a picture, but they can also display a message if you wanted them to.

Now Sofia, well, she's chosen to use an offboard buzzer as an output for her museum alarm system.

And the micro:bit's going to be connected to a push-to-make switch near the artefact.

And then the buzzer will sound if the switch is pressed.

And there you've got a picture of what that might actually look like in real life.

Other members of Class Six have also chosen outputs to use.

So Lucas is going to use an onboard microphone to sound a recorded message.

Jacob is gonna use an offboard LEDs to flash if signalled by the input.

And Laura is gonna use an offboard bulb which will light up if that's signalled by the input.

Again, Jacob and Laura this time have got quite similar ones, but they're using offboard LEDs or offboard bulbs.

So they are slightly different, but in some ways a similar effect.

Check for understanding, where is the speaker on the back of this micro:bit? Is it A, B, or C? That's right, well done.

It's B, that's where the speaker is.

Okay, I think you probably guess what's gonna be coming up in task B.

So it's very similar to task A, except we're now talking about the outputs.

So which outputs are gonna work well for your shoebox museum alarm? Think about if the output will be offboard or onboard and how is the output gonna be signalled by the input? So if you remember in task A, we talked about how, how is the input going to affect the output? Same sort of question here, but you've got to think about how are they going to relate together? So really think very carefully about how one will affect the other.

So now it's about making decisions about how, what output you're actually going to choose.

So work with your partner, come up with some ideas about what you're going to choose for your outputs for this museum alarm.

Right, well done.

Welcome back.

So Jun and Aisha discuss which outputs that would work well for them.

And they talked about if the outputs can be offboard or onboard, how the output will be signalled by the input.

And Aisha said, well, the micro:bit LEDs are gonna flash a message for her when it senses a light level change and it's gonna be next to the artefact.

And that will warn people from coming too close, which I think is a great idea.

Jun is going to have an offboard push-to-make switch next to the artefact.

And when that's pressed, it's gonna signal a buzzer, which is also gonna be another offboard component, which is gonna be outside the shoebox.

Two really good ideas.

They've thought very carefully about the input and about the output.

I'm sure you've come up with your own ideas and I hope you've come up with lots of different ideas as well, because you don't have to choose these ones.

There are lots of different combinations that you can go through.

Right, well done.

We're onto the third learning cycle.

And the third learning cycle is a bit of a discussion about design decisions.

So designers make design decisions before, during and after making their products.

And when they don't work as well as planned, they need to make decisions about how to change their designs and what they're going to do about it.

And Laura says, and she's quite right, "Changing designs and things is not working." It's okay, it's fine, it's fine if it doesn't work, because we learn from that.

That's where the learning comes in.

So well done, Laura.

You're absolutely right.

Check for understanding.

What happens if a design doesn't work? Is it A, nothing, we just leave it? B, changes might need to be made.

C, everything, the product has to be started all over again.

So which do you think it is? A, B, or C? Well done, you're absolutely right.

It's B, changes might need to be made.

Now Laura has already made some design decisions about the input, the output, and how her alarm system might work.

She's really thought carefully about all of these different things.

She's gonna use a photoresistor as an input.

She's gonna use a bulb as an output.

And when the light levels change, if a person gets too close, for example, the photoresistor sensors this, sends a signal to the micro:bit and that turns on the light bulb.

She's now gonna make design decisions about where those are gonna go in her prototype.

Says she's gonna put the photoresistor next to the artefact and the micro:bit and the bulb on the outside of the shoebox museum.

And the photoresistor fits really well, but unfortunately, the bulb isn't going to fit in the space that she wanted.

And now she's gonna have to make a design decision over what she's gonna do.

What do you think Laura could do? Right, well, Laura decided that she's got some choices to make.

So she could move where the bulb's gonna go.

She could change the bulb for a different output, use something different.

So what she decided was that actually she's going to use LEDs instead of the bulb and she can place this around the lid of the shoebox.

So that when the photoresistor sensors a change in light, then the LEDs will flash on and off.

So very similar to the bulb, but actually she's gonna use LEDs instead.

Check for understanding.

What are design decisions? Are they A, the colours we use when creating a product, B, the shapes we make when drawing a product, or C, the choices we make when creating a product? Is it A, B or C? That's right, well done, it's C.

Right, Laura continues to think about her work and now she's gonna start thinking about the impact that that decision has made for what she still doesn't know, what she still needs to do with her work.

So she still hasn't thought about the coding for the system yet.

She still needs to think about how to code the LEDs, not the bulb.

So she's, the impact of her choosing the bulb compared to the LEDs.

Is that gonna make much of a difference when she's coding? She's gonna have to think about that.

She also needs to know from a practical level, she's going to have to put wires in.

But how's she gonna hide those wires? Where's she going to put them? How's she going to connect them? And she needs to know how to secure those LEDs to the shoebox.

She's got a space for all them now, but actually how is she going to connect them up and how she gonna keep them secure? And lastly, she also needs to think about how to secure the photoresistor next to the artefacts that's gonna work.

She doesn't wanna just leave it lying around.

It needs to be in a more permanent place.

So it's actually set up really well.

But how's she gonna do that? How's she gonna hide the wires? Lots of things that she's still got to make design decisions about and that's fine.

It's okay to still have things that we know we've still got to solve problems for.

Laura then put that all together into a table and summarised her decision.

So she's definitely gonna use an offboard photoresistor.

She's going to use an offboard LED.

She's going to have those linked up so that when the photoresistor sensors a change in light, it will signal the micro:bit and she knows where they're gonna go, but she still needs to know how to code it correctly and how to hide the wires.

And she also knows that she might still have more design decisions to make, which is where you need to come in now with your design decisions.

So you need to think about what decisions you've made already and how are you going to plan for what you still need to know.

This is a really key part of design is not just thinking, "I know what I'm doing, I'm just gonna get on with it," but actually thinking very carefully and planning out, "What are my next steps? What do I still need to do?" And that's where this table might come in handy.

'Cause you can put down what you already know.

So what input, we talked about that in task A, what output, talked about that in task B.

Where the components will go.

So hopefully you can think about where they're actually gonna go in your work.

You might need to change your mind a bit like Laura did and that's absolutely fine, 'cause we're still in the planning and discussion stage.

How is the system gonna work? Well, that really depends upon the input and the output you choose.

And then if you know where the components are gonna go, if they still fit, then you can talk about how the system's gonna work.

And almost more importantly, what do you still need to know? What do you still need to do? That's quite an important task.

Right, we'll let you get on with that and give you a few minutes to do that and we'll come back with some feedback.

So Laura has summarised her design decisions so far and she planned what she still needed to know.

And this is something that she's already gone through.

She's talked about it, she's thought about it.

She's made no more changes than from last time.

But she still needs to know how to code correctly and how to hide the wires as well.

And they're quite important decisions that she knows she's gonna have to make and find design solutions for as she moves forwards.

Right, well done.

I hope you've got a really clear plan now of what you're doing, what your system's gonna look like, where it's gonna go, and also what you still need to do.

'Cause there's still so much yet to do, 'cause we're not quite finished with our museum box designs.

So we need to think about what do we need to do next? Right, and here's a summary of today's lesson.

So a micro:bit alarm could include onboard inputs such as an accelerometer, a magnetometer or light sensor.

A micro:bit alarm could include offboard inputs such as a photoresistor or push-to-make switch.

A micro:bit alarm could include onboard outputs such as an LED display or speaker.

And a micro:bit alarm could include offboard outputs such as buzzers or LEDs.

And the last key learning point from today is that design decisions need to be made as to what a designer wants the micro:bit to do.

Right, great.

Thank you very much for being with me today.

Hope you've learned a huge amount.

You've got a clear action plan for how to complete the shoebox museum and I look forward to working with you next time.

Thanks very much for being with me today.