Teacher guide Researching & planning ≈ 165 min

Lesson 4 · Weeks 5–7

Generating, developing & testing design ideas

Learning intention

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

Success criteria

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.

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.

ThinkerShields (for testing) · A3 paper for design sketches · PMI template · time/action plan template (resources view).

Read the brief again. What are we designing? Who for? What does success look like?
Brainstorm with the class: rooms, drawers, lockers, boxes, pet bowls, doors.
Show _10_Alarm_Basic.ino as a worked example; trace the four Status values.
Hand out the design template; set students off on four ideas + PMI.
Mid-lesson: walk a couple of design ideas to the whole class; coach the PMI process.

"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.

Provide a deck of input/output cards; students draw two cards and design an alarm around them.

Add a secondary input (e.g. a key-press code) for arming/disarming.

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

Syllabus outcomes hit by this lesson: TE4-1DP TE4-2DP TE4-4DP TE4-DES-02 TE4-PRO-01