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.
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.inosketch open as a worked model. - Set up a "design wall" — students can pin or photograph design sketches.
Generating, developing & testing design ideas
What you will be able to do
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.inosketch open as a worked model. - Set up a "design wall" — students can pin or photograph design sketches.
Today's work
Try it · keep the evidence
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.
Quick check
Show your reasoning
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.
Before you pack up
Explain what you learned
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
Explain it. Apply it.
Next lesson: Final design, circuits & electronics.