Bro's in Control - Make a funny voice recorder

micro:bit - the next gen

In the CBBC series Bro’s in Control, Adam, Joe and Callum have fun with the BBC micro:bit mini computer. Adam uses the sound recording and playback functions on the micro:bit to surprise Joe during a game of hide and seek.

Watch the video below with your class to see how things go and then try out one of the activities yourselves. You’ll also find teacher notes on this page along with a link to a video on the Micro:bit Educational Foundation website that explains the activity.

Teacher notes

Before watching

Introduce the BBC micro:bit device and the MakeCode programming platform.

Discuss what pupils already know about recording and playing back sound using devices like phones and tablets, and what they know about microphones and speakers.

Ask pupils to share what they already know about using sensors and controlling devices remotely - link to their own senses and familiar sensors they may have already encountered, e.g. smoke alarms, automatic doors, automatic lighting, smart speakers etc.

After watching

Clarify what the different prank devices actually did and how the micro:bit was involved:

• Joe was detected by two micro:bits outside of the wardrobe when he broke an invisible radio beam. This sent a radio message to the micro:bit inside the wardrobe which played a pre-recorded sound. When the wardrobe door was opened, the light sensor on the micro:bit detected this and Joe’s voice and recorded him before playing it back like a parrot.
• The signs were triggered by the proximity sensor on two micro:bits that sent radio signals to initiate the trigger.
• The loud scream was triggered using the proximity sensor. When the invisible beam was broken it sent a radio trigger to play a loud scream on a micro:bit that was attached to a speaker.

Visit the project page on the Micro:bit Educational Foundation website and work through the steps to:

• Complete the coding project to create a funny voice recorder
• Try out the device in small groups

After completing the activity

Discuss what you discovered during the project:

• What happens to a sound recording when the micro:bit is turned off?
• Can more than one sound be stored at a time?
• How many different ways did the micro:bit receive input? – sound, light, motion etc
• How many different ways did the micro:bit produce output? – sound, motion etc
• What other computer devices have you seen that use a microphone, speakers or sensors?

Extension activities

• Use the micro:bit’s built-in microphone and speaker to make a mini-jukebox that plays your own songs
• Explore changing the sample rate for recording and playback- what does the recoding sound like?
• Use a micro:bit to create a classroom alert that will remind children to stay quiet when they are working
• Create a glossary of the key vocabulary used in the project – use words, symbols and pictures
• Draw flow charts with boxes and arrows that show how the different surprises work
• Create a cartoon strip showing Adam and Joe and the different prank devices they created
• Take a photo of one or the devices and label it to show where all the different parts of the micro:bit are located
• Make a video advert for one of the prank devices explaining how it works
• Make a list of different ways versions of the micro:bit devices you have made could be used to help people rather than surprise them
• Think about how the devices you created could be used to help prevent your stuff from being stolen

Suggestions for activities for children with special educational needs

• Sequence photos of the surprise devices to show the order in which the surprise happens
• Use a laptop/tablet to record children explaining how to use the micro:bit – “talking instructions”
• Match human senses to some of the micro:bit sensors and built-in devices
• Create a visual dictionary for key vocabulary with pictures/symbols – drawn by pupils or cut and stick
• Complete gap-fill descriptions and explanations about the project using word-banks of key vocabulary
• Match images and simple descriptions/labels of the micro:bit device
• Label printed photos of the different micro:bit devices with simple annotations and key vocabulary

Download as a PDF: Computing topics covered | Cross-curricular links and activities

Educational context

Microphones
Microphones work by converting sound vibrations into electrical signals that can be stored and transmitted. A microphone has a small thin layer of material that will vibrate when sound waves from a noise or voice reach it. These vibrations are used to move a magnet or an electrical coil that turn the sound waves into electrical signals. Digital microphones convert these electrical signals into digital data that can be stored and used by a computing device or sent to a speaker so we can hear it.

Speakers
A speaker is a device that can take electrical signals and turn them into sound waves that we can hear. It does this by using the electrical signal to move a cone made from thin flexible material backwards and forwards. This movement creates sound waves in the air that can then travel into our ears and be heard. Digital speakers can read a digital sound file and convert it back into sound waves that will move the speaker cone and produce sound waves in the air so we can hear it with our ears.

Sensors
Humans use their five senses to find out what is happening in the world around them. Other animals may have extra senses that humans don’t have. Having senses means we can react to things around us, and stay out of danger. Computer sensors also collect information about the world. They convert this information into digital data and it can then be understood by a computer. We can program the computer to react to this information in a particular way, by making a sound, or switching something on or off. For example, an automatic door has a sensor that can tell if there is movement nearby and open to let someone through.

You can watch Bro's in Control on CBBC or on BBC iPlayer

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