micro:bit Challenge Creator — Lesson 2 — Year 7 Digital Technologies

This project: ← 1 · Play, Understand & Improve 2 · Radio, Design & Build

👋 Welcome back — Lesson 2. First see how micro:bits talk to each other by radio, then design, build, test and share your own micro:bit game.

Your answers from Lesson 1 are saved on this computer. New to this machine? Use ↥ Restore from file to load the file you downloaded last lesson. ← back to Lesson 1

Name Class Teacher

📡 Section 4 — How micro:bits talk (radio demo)

Watch the teacher demonstration: one micro:bit sends a message and another receives it with no cables.

Key idea: SEND → (radio signal) → RECEIVE

Question	Your answer
What did the first micro:bit do?
What happened on the second micro:bit?
Did they use cables?
What was sent between them?

🐞 There are 2 mistakes in the code below that stop it working. What are they, and how would you fix them?

Sending device

on start radio set group 1 on button A pressed radio send string "Boo" on button B pressed radio send string "Aaargh"

Receiving device

on start radio set group 1 on radio received receivedNumber show string "receivedNumber"

Mistake 1 — what's wrong and how to fix it: Mistake 2 — what's wrong and how to fix it:

Mistake 1: the receiver listens with on radio received receivedNumber (the number block), but the sender sends text ("Boo"/"Aaargh"). Use the string receive block — on radio received receivedString — so it matches what was sent.
Mistake 2: show string "receivedNumber" has the variable name in quote marks, so it shows the literal words instead of the message. Remove the quotes and show the received variable itself, so the actual message appears.

I understand how micro:bits communicate

🤝 Section 5 — Add multiplayer (radio extension)

Task 4: upgrade Rock–Paper–Scissors so two players can interact using radio. Plan the three steps.

Step	Description
1
2
3

Winner helper: same choice = draw; different choices, decide who wins (e.g. rock beats scissors).

Feature	Your idea
What will your micro:bit send?
What will it receive?
How will it decide a winner?

My micro:bit sends data
My micro:bit receives data

🧠 Section 6 — Design Thinking Studio

Before you build, think like a designer: lots of ideas, think about the player, refine the plan.

Task 1 — Ideation: what is the challenge? What makes it interesting?

Idea	What is the challenge? What makes it interesting?
1
2
3
4

Stretch thinking — what vibe?

Task 2 — Your best idea is number… and why?

Task 3 — Design details

Element	Your design
Game name
Theme (funny, battle, race…)
What happens in the game?
Input (e.g. shake, button)
Output (LED, sound, radio)
Goal
Fail condition

⚖️ Balance & multiplayer design

Question	Your response
What skill is needed to win?
What makes it challenging?
Is there randomness?
How will you make it fair?

Task 5 — Multiplayer design (radio extension)

Between players	What happens?
Player 1 action
Player 2 action
What is sent (radio)
How the winner is decided

How does adding another player make your game better? Task 6 — Quick sketch (describe it): PLAYER ACTION → MICRO:BIT RESPONSE → RESULT

I created multiple ideas
I chose the best idea and explained why
My game has clear rules, a goal and a fail condition
I planned the inputs and outputs
I considered difficulty and multiplayer (extension)

🎯 Section 7 — Design your challenge

Your mission: create a new challenge inspired by Rock–Paper–Scissors.

Idea	Description
1
2
3

My final idea:

Challenge requirements

Use at least one input
Use at least one output
Include a goal
Include a fail condition
Be playable in under 1 minute

High-achievement extension

Use radio communication
Include two-player interaction

Element	Your design
Game name
Input
Output
Goal
How you lose
Random element?
Multiplayer? (radio)

💻 Section 8 — Build your program

Task 5: plan the logic of your code before you build it. (Use the micro:bit Editor tab to build it.)

Code planner

START:
When happens →
  Do
If →
  Then
Else →

If using radio:

Send: Receive: React:

My program runs
My inputs work
My outputs display correctly
Radio works (if used)

📝 Section 9 — Write player instructions

Challenge name: How to play: Goal: How do players lose?

🏁 Section 10 — Challenge Arcade

Play other students' games, test them, and give useful feedback.

Game	Fun (1–5)	Clear?	Easy / Hard?	Notes

Radio battle mode (if used)

Did it connect successfully?
Did both players interact?
Was the result fair?

What will you fix or improve after feedback?

⭐ Extension — challenge ladder (for fast finishers)

Finished building and tested your game? Climb as far up the ladder as you can. Pick any challenge, plan it in the box, then build it in the micro:bit Editor tab. More stars = harder.

⭐ have a go · ⭐⭐ stretch · ⭐⭐⭐ boss level

⭐ Keep score — add a score variable that goes up by 1 each time you win a round, and show it when you press a button. How will you store and show the score? ⭐⭐ Private channel — use radio set group so only you and your partner hear each other (every other pair picks a different number). What group number did your pair choose, and why does this stop crosstalk with other groups?

⭐⭐ Auto-judge over radio — both players send a number for their choice (0 = rock, 1 = paper, 2 = scissors). When you receive your opponent's number, use if / else to show Win, Lose or Draw. Write the rule that decides the winner:

Hint — the sending half

let myChoice = 0
radio.setGroup(3)
input.onGesture(Gesture.Shake, function () {
    myChoice = randint(0, 2)
    radio.sendNumber(myChoice)
    basic.showNumber(myChoice)
})

Then in radio.onReceivedNumber: it's a draw if both numbers match. Otherwise you win if your choice beats theirs — rock(0) beats scissors(2), paper(1) beats rock(0), scissors(2) beats paper(1). (Neat trick for the win case: it's a win when (myChoice − theirChoice + 3) % 3 == 1.)

⭐⭐⭐ Bigger game — extend Rock–Paper–Scissors to five options (e.g. add Lizard and Spock). Write what beats what, and describe how you'd change the winner check in code. ⭐⭐⭐ Invent a new two-player radio game — design something different (e.g. a reaction duel: first to shake after the LEDs flash wins). Plan it as input → process (with radio) → output, and state the win condition.

I attempted at least one ⭐⭐ challenge
I built and tested it on the micro:bit (or simulator)
I reached a ⭐⭐⭐ boss level

💭 Section 11 — Reflection

What did you learn from building Rock–Paper–Scissors? How did radio change your game? What was the hardest part? What would you improve next time?

Use input and output
Modify a program
Create a working challenge
Write clear instructions
Use radio (extension)

Nice work — when you're done, hit ⬇ Download my work and hand it in. — Mr Wong

🧩 micro:bit MakeCode editor ↗ Open in a new tab

Build, test in the simulator, then download the .hex to your micro:bit. Your code is saved inside the editor on this computer (separately from your workbook answers). If the editor doesn't load below, your school network may block it — use the “Open in a new tab” button.

📡 Radio reference (for Sections 4 & 5)

Two micro:bits can talk if they are on the same group. One sends, the other receives the same kind of message (both strings, or both numbers).

SENDER

radio.setGroup(1)
input.onButtonPressed(Button.A, function () {
    radio.sendString("rock")
})

RECEIVER (correct)

radio.setGroup(1)
radio.onReceivedString(function (receivedString) {
    basic.showString(receivedString)
})

Both micro:bits must use the same group number. The sender uses sendString, so the receiver must use onReceivedString and show the variable (no quote marks) — that's exactly the two fixes from the Section 4 puzzle.

💡 Rock–Paper–Scissors starter

Need the original game to build on? In the micro:bit Editor tab, switch to JavaScript, select all, and paste this in. Switch back to Blocks to see it as blocks.

input.onGesture(Gesture.Shake, function () {
    let choice = randint(0, 2)
    if (choice == 0) {
        basic.showString("R")   // Rock
    } else if (choice == 1) {
        basic.showString("P")   // Paper
    } else {
        basic.showString("S")   // Scissors
    }
})

Tip: combine this with the radio blocks above for a two-player version.

💾 How your work is saved

Autosave: everything you type saves in this browser automatically — including your Lesson 1 answers.
Same computer, same browser: your answers come back when you return — but only on this device, and they can be lost if the browser data is cleared.
Switched computers? Click ↥ Restore from file and choose the file you downloaded last lesson.
To hand in: click ⬇ Download my work (it includes both lessons) or use 🖨️ Print / PDF.