Lesson 1 - micro:bit: Guardian of Marine Life
1. Engage: How Do Sea Turtles Find Their Home Beach?
Let’s start with a fascinating story! Imagine a baby sea turtle hatching on a warm beach, crawling into the ocean, and swimming far, far away. Years later, when it’s grown up, it swims back exactly to the same beach where it was born to lay its own eggs.
Show students a short video or photos of baby sea turtles hatching and adult turtles nesting.
Key Question
If you were a sea turtle, what tool would help you find your way home?
Discuss student ideas (maps? stars? signs?).
Then reveal:“Scientists discovered sea turtles use Earth’s magnetic field—like a hidden compass inside their bodies!”
Share a simple diagram of Earth’s magnetic field.
Explain: “Every beach has a unique ‘magnetic signature”, and turtles remember it like a secret code!”
2. Explore: Sensing Earth’s Magnetic Field with micro:bit
Today, we’ll meet the micro:bit! It has a special sensor—the compass, just like the one sea turtles use to sense Earth’s magnetic field.
Activity 1
Meet the micro:bit Compass
Show the micro:bit and point to its components: “This tiny board has a brain (processor) and a compass sensor—let’s find it!”
Key Question
If you use the micro:bit to simulate a compass, what will be displayed when you spin around holding the micro:bit? Why?
We can display arrow or compass headings on the micro:bit.
Similar to sea turtles: Their bodies sense the same magnetic "map"—and we can see it on the micro:bit, more specifically! Let’s try to show specific compass headings on the micro:bit.
3. Engineer: Program the micro:bit to Show Compass Heading
Let’s teach the micro:bit to show compass headings like a sea turtle! We’ll use the coding platform - MakeCode.
Coding Steps:
1.Open Microsoft MakeCode through the link below.
https://makecode.microbit.org/
2.Create a new project named “Turtle Compass”.
3.Drag a show number block into the forever loop from Basic.
4.From the “Input” category, drag a compass heading block and connect it to a show number block.
Your code should look like this:
Key Question
What do the different numbers mean? What is the number range?
Test the Code: Plug the micro:bit into a computer with a Micro-USB cable. Click "Download" to send the code. Hold the micro:bit and rotate it. What number shows when you face north? east?
Note: The first time you start using the compass of a micro:bit, it will start calibrating the compass (adjusting itself). Tilt it to fill the screen to complete the calibration.
Make sure to use the compass away from metal, as this may confuse the micro:bit.
4. Experience & Challenge: Help Turtles Find Their Way Home!
Let’s create this project and find out the relationship between numbers and the directions.
Activity 2
Prepare sticky notes with arrows on the ground that point to north, east, south, and west.
Guide students to complete the program, download it to their micro:bits, follow the arrows on the ground, and record the numbers displayed on the micro:bits.
Let's take on a challenge! The goal is to use the micro:bit to make a navigator that can help a blindfolded classmate pretending to be a sea turtle find their home beach (northeast).
Activity 3
Guide the students to import the program provided by the teacher, complete it correctly, and upload it.
After completing the program, organize groups to test their navigators according to the rules below:
(1)One student is the “turtle” (blindfolded, holds the micro:bit) and team members stand at the finish point (northeast direction).
(2)The "turtle" turns around 3 times and starts finding its way home according to the sound prompts from the micro:bit. Others must not interfere with the "turtle".
(3)The fastest team to reach the home beach with correct direction wins!
5. Elaborate: Protecting Turtles—Our Role in SDG 14
Sea turtles rely on their magnetic sense to survive, but human actions can confuse them:
(1)Plastic trash in the ocean (turtles mistake it for food).
(2)Lights on beaches (baby turtles crawl toward lights instead of the ocean).
(3)Beach construction (destroys nesting spots).
Brainstorm: “What can we do to help?” (e.g., pick up trash, use dim beach lights, plant beach grass to protect nests).
Create a class poster: “10 Ways to Protect Sea Turtles & Their Ocean”.
Wrap Up:“Today, we used micro:bit’s compass to act like sea turtles—but the real hero is YOU! By protecting oceans and creatures, we ensure turtles never lose their way home. That’s how we support SDG 14: Life Below Water!”
Lesson1.zip 
