MicroFit - Your very own Step Counter

Overview

Ever wondered how a smartwatch or fitness band counts your steps? In this project, you're going to build your very own step counter using a micro:bitmicro:bitThe micro:bit is a tiny programmable computer, about the size of a matchbox, made for learning to code. It has two buttons, a grid of little red LED lights and built-in sensors that can detect movement, light and temperature.Full entry →!

Inside your micro:bit is a clever little sensor called an accelerometerAccelerometerAn accelerometer is a tiny part inside the micro:bit that senses movement, like tilting, shaking or being turned over. It turns that movement into numbers your code can react to.Full entry →. It can feel when the micro:bit moves. We'll use it to spot every step you take, add them up, and show the total on the LED matrixLED MatrixThe LED matrix is the grid of little red lights on the front of the micro:bit. By switching them on and off in patterns, your code can show numbers, letters and tiny pictures.Full entry → (the grid of lights on the front).

The best bit? When you're done, you'll have a real working fitness tracker you can pop on and take outside. Don't worry if something doesn't work first time, that's all part of coding. Let's give it a go!

What you'll need

Key words

Set up your micro:bit EduBlocks Editor

1. Open your web browser. We recommend Google Chrome or Microsoft Edge.
2. In the address bar type app.edublocks.org.
3. Under Create New Project, select micro:bit. Name your project MicroFit, and make sure block is selected under type.

4. Select Create to open the micro:bit editor.

Import the MicroPython library

Select Basic, then Imports, then snap a from microbit import * block onto the #start code here block.

This imports the micro:bit library into EduBlocks so we can use all the micro:bit's functions.

Set steps to 0

1. Select Variables, choose Create a Variable, and name it steps.
2. Snap a steps = 0 block to the from microbit import * block.

This makes a variableVariableA variable is something that can change. Think of it like a labelled box: you pop something inside, and the label tells you what it is. You can swap what's inside whenever you like.Full entry → called steps and starts it at zero.

Create a while True loop

Select Basic, then Loops, then snap a while True: block onto the steps = 0 block.

This while loopWhile loopA while loop keeps repeating its instructions for as long as something stays true. The moment that thing stops being true, the loop stops.Full entry → gives us a space to put code that repeats forever.

Detect a shake

1. Select Basic, then Logic, then drag an if True: block inside the while True: block.
2. Select Accelerometer, then snap an accelerometer.was_gesture("shake") block onto the if block where it says True.

This if statementIf statementAn if statement checks whether something is true, and only runs its instructions when it is. It's how code makes decisions.Full entry → runs its code only when the micro:bit feels a shake.

Increase the steps

1. Select Variables, then snap a steps = 0 block inside the if accelerometer.was_gesture("shake"): block.
2. Change the = to += and the 0 to 1.

Now every detected shake adds one to your step count.

Pause the code

Select Basic, then Statements, then snap a sleep (1000) block below the if accelerometer.was_gesture("shake"): block, lined up with the if (inside the while True: loop, but not inside the if). Change 1000 to 500.

This pauses for half a second so the loop has time to notice the button press we'll add next.

Reset the steps with button A

1. Select Basic, then Logic, then snap an if True: block onto the sleep (500) block.
2. Select Buttons, then snap a button_a.was_pressed() block onto the if block where it says True.
3. Select Variables, then snap a steps = 0 block inside the if button_a.was_pressed(): block.

Pressing buttonButtonA button is a switch you press to tell your project to do something. The code can check whether it's being pressed or not.Full entry → A now resets your step count back to zero.

Show the number of steps

1. Select Display, then snap a display.scroll ("Hello World") block just below the if button_a.was_pressed(): block.
2. Select Variables, then snap a steps block onto the display.scroll block, over the words "Hello World".

This block sits inside the loop but not inside the button A block, so your steps scroll across the LED matrixLED MatrixThe LED matrix is the grid of little red lights on the front of the micro:bit. By switching them on and off in patterns, your code can show numbers, letters and tiny pictures.Full entry → all the time, not just when you press A.

Downloading the Code

1. Connect the micro:bit to the computer with the micro USB cable.
2. Select Connect and follow the on-screen prompts to pair the micro:bit with your web browser.
3. Select Download to send the code to your micro:bit.

Run it and Watch

In the web browser

EduBlocks has a built-in micro:bit simulator, handy if you haven't got a micro:bit to hand.

1. On the right-hand side of the screen, select Simulator.
2. From the accelerometer menu below the simulator, select Shake.
3. Select Send. This simulates a shake and shows a number on the simulated micro:bit.

On a real micro:bit

Once your code's downloaded, give the micro:bit a shake. Each shake bumps your step count up by one on the LED matrix. Pop a battery pack on, attach it to your wrist or ankle, and head outside to watch your steps climb.

Try it yourself

Stuck? Quick fixes