Challenge 1 – Detect input, create output

Let’s start by detecting an input created by a person, then create an output based on that input. You’ve seen a simple example of this in the previous week where the step counter was being displayed on the micro:bit’s screen after a person pressed one of the micro:bit buttons. That was taking an input (the button press) and creating an output (the number on the micro:bit’s screen).

In this challenge, we’re going to use the micro:bit’s pins to detect touch, and play a sound through a speaker that we attach. We’ll code two different pins on the micro:bit to each play a different sound.

Equipment

You can code and test this challenge using the simulator. If you have a micro:bit you’ll have also need – 3 x clips – a speaker with its own power source or a pair of headphones – something conductive like tinfoil or fruit

In the UK, we call clips crocodile clips. In the US, they are called alligator clips!

Pins on the micro:bit

Watch the video below to learn more about the micro:bit’s pins

Setup the Speaker

###Code Test the speaker is working by putting some test code in the block On button A press. If you have a speaker on your computer that you’re coding with, you can test your code by pressing the A button on the simulator. Use the simulator to find your favourite melody!

Build

+Connect the speaker to the micro:bit using two clips. +Add one clip to GND and +the other to Pin 0

The speaker only works connected to Pin 0. Connect the clips to the speaker jack, one at the bottom, one at the top.

_{Speaker setup}
(Click to expand)

Play

To play the test sound, press button A. Watch the video in the next step for a demonstration.

Add your own keys

You can extend the pins on the micro:bit using clips. Attach a clip to Pin 1 and Pin 2.

You can attach a conductive item to the end of the clips then touch them: in the next step I use fruit and also tinfoil.

Below is the final setup with the keys and the speaker attached. And the code I used to create my musical piano.

_{Final setup}
(Click to expand)

To play your keyboard you need to hold Pin 1 or 2 and GND to play your sound.

In the next step you will watch a video that shows this challenge in action.