Crack the Code · Stage 4

Weeks 5–7 · Generating, developing & testing design ideas

Generate four alarm-system design ideas, evaluate each with PMI, choose two to test, and pick the strongest to take forward as your project.

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Open this deck on the projector and press F for full-screen. N toggles speaker notes. The accompanying teacher guide is at /curriculum/crack-the-code/teacher/lessons/4.

Before this lesson:

Print or share the design ideas template and the PMI sheet (resources view).
Have the _10_Alarm_Basic.ino sketch open as a worked model.
Set up a "design wall" — students can pin or photograph design sketches.

intention 2 min

Generating, developing & testing design ideas

Generate four alarm-system design ideas, evaluate each with PMI, choose two to test, and pick the strongest to take forward as your project.

Print or share the design ideas template and the PMI sheet (resources view).
Have the _10_Alarm_Basic.ino sketch open as a worked model.
Set up a "design wall" — students can pin or photograph design sketches.

task 30 min

Today's work

Review the design brief and complete the KWL chart; complete an IPO chart for the project; brainstorm possible solutions.
Generate four design ideas — each with a name, an end-use application and an IPO chart — and evaluate each with Plus / Minus / Interesting (PMI), using class work and internet research as stimulus.
Complete the time/action plan and finance plan; list component-sourcing websites.
Test two ideas in class (insert a screenshot of the code into the folio), evaluate each with PMI, and justify the final selection by linking it to the design brief and criteria for success; draw the flowchart and write the pseudocode for the chosen design.

Explain the Know–Want–Learned (KWL) chart with reference to the design brief, constraints and criteria for success.
Explain that students must develop four basic control-system designs using the Arduino; describe what makes a good design solution (closed loop, simple functions, a clear end-use application).
Support project management: students complete a time/action plan (action · expected completion · ongoing evaluation), finance/cost planning for consumables, and a list of websites to source components.
Have students test two of their design ideas in class against the criteria for success, evaluate each with PMI, and justify their final choice. Note: once the code works on the ThinkerShield, students remove it and assemble the circuit from components.

check 3 min

Quick check

I can generate four distinct alarm-system designs, each with an IPO chart and an end-use application.
I can evaluate each design with Plus / Minus / Interesting and reference the brief and criteria.
I can plan time, action and finances for my chosen design.
I can test two designs on the ThinkerShield and justify which one I'm taking forward.

"More features = better design" — the brief asks for one working input + one working output that branches; over-scoping makes it harder to finish.
"I'll figure out the code later" — students should test their proposed code on the ThinkerShield before committing to a design.

reflect 3 min

Before you pack up

Why did you pick the design you're taking forward, in terms of the design brief and the criteria for success?

Four design ideas with IPO charts and PMI evaluations.
Two-design test report with code screenshots and an evaluation.
Time/action plan with at least three ongoing-evaluation entries.
Finance plan for the consumables the student will need.

End of lesson 4

That's it.

Tomorrow / next lesson: Final design, circuits & electronics.

Teacher guide Next lesson's deck → All decks