Introduction

Aims

In this part of the activity we will:

  • Measure sound (an input) using the microbit
  • Make a real time graph of the sound level on the computer
  • Visualise the sound level on the micro:bit

Learning outcomes

Learning outcome
Inputs Measuring inputs with a microcontroller
Graphing serial data Graph serial data on a pc
Visualise data Visualise data on the micro:bit

Preperation

Equipment required

Equipment item Quantity
Laptop/PC 1
Micro:bit 1
USB cable 1

Activity

Measure sound using the microbit

Write the program below

This program uses serial communication to send the sound value the micro:bit measures back to the computer so that we can look at the value it on the computer screen. (We can imagine this like the microbit having a conversation with the computer)

Blocks Python
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Now check the program works!

There are some instructions in the image below

  • Try it out in the simulator first
  • Then try it out for real on your micro:bit
  • Note you need to be connected to the micro:bit for this to work (both with a usb cable, and in the makeCode environment)

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Important Questions

  • What sound values do you see in the simulation? in real life?
  • What is the maximum? What is the minimum?
👉🏾 Answer
  1. In the simulation you should see a minimum of 0, and a maximum of 255
  2. In real life, the values seem to range from 0 to 131!

Now lets visualise the sound measurement on the micro:bit

  • Write the program below
  • This program allows us to plot a graph on the micro:bit leds to show how loud the sound is!
    • If you’re interested, the documentation for the bar graph is here
  • Check it is working correctly, you can check how it works in the simulator
Blocks Python
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