A Years 8–9 design project: a parking assistant with an ultrasonic sensor and three warning bands, planned with band-edge tests, prototyped on the board, built in Tinkercad and optionally on hardware, tested with a ruler and evaluated.
Capstone projects · Years 8–9: sense and respond · about 180 minutes · Open the student lesson
Classroom resources
Load these into Waypoints Prepare: choose Load URL and paste the copied address, or download the file and import it. In Prepare, the worksheet's Teacher edition shows the answers; the student copy hides them.
SlidesDownload Present from the browser, or export to PowerPoint or PDF.
WorksheetDownload Print the student copy; the Teacher edition has the answers.
Students will be able to
I can plan tests for every edge of a set of bands.
I can read a distance sensor and act on it.
I can evaluate my design against each criterion with evidence.
Timing
About 3 to 4 lessons (around 180 minutes). Inquire part lesson · Develop 1 · Create 1–2 · Test and evaluate 1
Before class
The sensor code (pulseIn and ÷ 58) is new: give it as a recipe card. HC-SR04 sensors are unreliable on soft or angled surfaces and under about 2 cm; good evaluations mention it. Builds on Arduino › A small system.
If you assess with MYP Design, the steps line up with the criteria:
A Inquiring and analysing: the brief, its criteria and constraints, and research into parts (Inquire).
B Developing ideas: a design specification, the circuit and code plan, and the test table written before building (Develop).
C Creating the solution: building it (in the simulator, then for real), following the plan and justifying changes (Create).
D Evaluating: testing against the specification, recording failures, improvements and impact (Test, Evaluate).
Otherwise, use the same four headings as a simple rubric: each step's reflect checks are the evidence list.
Running the lesson
Develop: ask how many edges three bands have.
Test: rulers out; record the real distance and what the device did.
The hard part (on purpose)
Real ultrasonic readings jump around; students blame their code. Print the readings first.
When students get stuck
What you will see
A question to ask
The fix
The readings jump around.
What does the sensor read when nothing moves?
Average three readings, or aim at a flat, hard surface.
Answers to the checks
Inquire: the brief: Sort each line of the brief: a criterion (what it must do, which you can test) or a constraint (a limit you must work within)? Off over 100 cm → Criterion; Blinks or beeps from 30 to 100 cm → Criterion; Steady under 30 cm → Criterion; HC-SR04 sensor and a buzzer or LED from the kit → Constraint; USB power → Constraint Criteria are what you will test at the end; constraints decide what you are allowed to build with.
Band edges: How many test readings do you need at minimum to check every band edge (30 and 100), on both sides? 4: 29, 30, 100, 101 Each edge needs the reading just inside and just outside it.
Prototype the bands: Here the knob reading stands in for the distance in cm. Write the bands so all six tests pass.
if (cm < 30) steady; else if (cm <= 100) blink; else off.
Which is evidence?: Which is the strongest evidence that the design meets a criterion? A test from the table that set the input and recorded the expected result A planned test with a recorded result is evidence; everything else is a feeling.
Stretch and support
Stretch: Beep faster as it gets closer, with the delay worked out from the distance (map).
Support: A recipe card for reading the HC-SR04, and the band table half filled.
Exit ticket
Give the four test distances that check your band edges.
29, 30, 100 and 101 cm.
What each step is for
Inquire: the brief: Separating what the design must do (criteria) from the limits it works within (constraints) is the first move of any design brief.
Develop: plan before you build: Three bands mean four edges to test; prototyping the bands on the board, with the knob as the distance in cm, gets the logic right before the sensor code.
Create: build it: Building in the simulator first catches wiring and code slips cheaply; the real build then tests the design against the world.
Test: run your table: Running the test table written in Develop, and recording every result including failures, is the evidence for the evaluation.
Evaluate: against the brief: Judging the design criterion by criterion, with evidence from the tests, is what separates an evaluation from a description.
Where it leads
Other Years 8–9 projects: Smart plant monitor, Reaction game.