Flashlight Logic

Overview

Today students start coding loops and conditions in MakeCode by building a simple “flashlight” app for a micro:bit. Students will connect logical statements to real app behavior: choosing brightness and then using loops to keep the brightness pattern going.

Learning intentions

• Students will be able to explain what a loop does in a program.
• Students will be able to use an if/else condition to choose behavior based on an input.
• Students will be able to design a short flashlight routine using a loop that maintains brightness.
• Students will be able to debug a program by checking how conditions control what the loop repeats.

Success criteria

• I can describe (in my own words) how a loop repeats steps.
• I can write an if/else condition that changes the flashlight behavior.
• I can use a loop so the flashlight brightness stays on or follows a pattern without manual restarting.
• I can test and fix at least one bug in my flashlight program.

Curriculum links

• Number System — positive and negative quantities and meaning of 0 in real contexts (used today as “brightness level” magnitude with possible “off” at 0).
• Number System — absolute value as distance from 0, interpreted as magnitude (used when students describe brightness as a magnitude).
• Number System — interpreting inequalities on a number line (used when students compare sensor/button values to decide “on/off/low/high”).

Lesson structure (45 minutes)

1. 0–5 min · Hook (App demo + quick talk). Teacher shows a short MakeCode or simulated flashlight effect (steady on, then blinking) and asks: “What parts tell the micro:bit to repeat, and what parts decide what brightness to use?” Students turn-and-talk and share 1 idea.

2. 5–12 min · Mini lesson: loops + conditions. Teacher models two code ideas on the board:

• Condition: “If button A is pressed, set brightness to 9; else set to 0.”
• Loop: “Repeat forever: keep setting brightness and show the pattern.” Students identify which lines are “decision” vs “repeat” and label them on a simple example handout.

3. 12–20 min · Plan it (flowchart + roles). Teacher gives students a one-page flowchart template (input → condition → brightness output → loop). Students complete the flowchart for their app choice:

• Option A: Button toggles between OFF (0) and ON (max brightness).
• Option B: If input is “low,” blink slowly; else blink quickly (still using brightness levels, with 0 as off).

4. 20–32 min · Build in MakeCode (teacher guided). Teacher circulates while the class follows a baseline build:

• Start with an if/else using a simple input (button press or accelerometer direction).
• Add a loop (forever) so the flashlight behavior continues.
• Set LED brightness/output for each branch (brightness = a numeric magnitude; include “0” for off). Students build their program to match their flowchart, using at least one condition and one loop.

5. 32–38 min · Debug sprint (test, observe, fix). Teacher asks students to run “3 tests”:

• Test 1: trigger OFF case
• Test 2: trigger ON case
• Test 3: confirm the loop keeps behavior going Students use a “Fix-It Checklist” to change only what is needed (e.g., wrong branch, missing loop, brightness not set to 0 when off).

6. 38–45 min · Share-out + exit ticket. Teacher selects 3–4 quick demonstrations (focus: “Show me the loop” and “Show me the condition”). Students answer the exit ticket:

• “Circle the part that repeats.”
• “Write one sentence: What condition decides what happens?”

Resources

• MakeCode (micro:bit) devices or computers for 25 students
• Student flowchart template (printed or digital)
• Fix-It Checklist (printout)
• Starter code cards (button/if/else + loop blocks)
• Headphones optional for quiet testing
• Projection of target example app
• Exit ticket slips or digital form
• Timer for the debug sprint

Assessment

• Formative checks during build: teacher listens for correct “decision vs repeat” language.
• Debug sprint: check whether students can identify whether the bug is in the condition or the loop.
• Exit ticket: students must correctly describe which part repeats and what condition controls behavior.

Differentiation

• Support: provide sentence starters for flowcharts (“If ___ then brightness is ___.” “Else brightness is ___.”) and a partially completed starter flowchart.
• Support: offer a “minimum viable” flashlight target (only one condition + forever loop with OFF/ON).
• Extension: challenge students to add a second condition (e.g., Button A sets brightness, Button B changes pattern speed) while still using a loop.
• EAL/SEN: allow students to use symbols in the flowchart (OFF/ON, ↑/↓ for brightness) and verify understanding with oral checks before coding.