Design a small robot base that follows a line or avoids obstacles: two motors through a driver, a battery chosen against the brief, gearing and a chassis, tested on a course.
Every robot competition starts with the same question: can it drive where you want, for long enough, without falling apart?
Client: the STEM club, for a line-following or obstacle course. Context: a 2 m course on the floor.
Brief: complete the course in under 60 s, without leaving the line (or touching an obstacle) more than once, and run for 30 minutes on one battery. Two DC gear motors through a motor driver, a battery of 6 to 9 V weighing at most 150 g, a chassis that fits in 20 × 20 cm.
Inquire: Read the brief: who it is for, what it must do (criteria) and the limits (constraints).
Develop: Plan before you build: parts, circuit, code and the tests you will run.
Create: Build it, first in the simulator, then for real if you have the kit. Expect a few tries; that is normal.
Test: Run your tests and record what happened, including what failed.
Evaluate: Judge it against each criterion, and say what you would change.
Make your prediction first. Help opens once you've locked it in.
InquireRead the brief: who it is for, what it must do (criteria) and the limits (constraints).
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)?
Completes the course in under 60 s
Leaves the line at most once
Runs for 30 minutes on one battery
Two DC gear motors and a motor driver
Battery 6–9 V, at most 150 g
Chassis fits in 20 × 20 cm
DevelopPlan before you build: parts, circuit, code and the tests you will run.
Develop: plan before you build
Try it yourselfYour edits are saved in this browser.
The two motors and the board draw about 900 mA together. Choose a battery that meets the brief (30 minutes using 80%, 6–9 V, 150 g at most).
Use the board. This ticks when you get there.
CreateBuild it, first in the simulator, then for real if you have the kit. Expect a few tries; that is normal.
Create: build it
TestRun your tests and record what happened, including what failed.
Test: run your table
EvaluateJudge it against each criterion, and say what you would change.
Evaluate: against the brief
For teachers
A Years 9–10 design project: a two-motor drive base for a line or obstacle course, with a battery chosen against the brief, steering planned, built in a simulator then for real, and tested on a timed course. About 300 minutes.
I can choose a battery and motors against a brief.
I can plan a robot's steering from its sensors.
I can test a robot on a course and evaluate it with data.
Before class
Needs Power and motors (drivers, shared ground, batteries); LiPos only after the LiPo safety sign-off and if your risk assessment allows. Pairs with Mechanisms (gearing), CAD (a printed chassis) and the robotics simulator. The micro:bit Cutebot (Code › Robotics challenges) is a ready-made alternative base for classes without kits.
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: the battery choice must be justified against all three numbers.
Create: drive straight first, then add one sensor.
Test: three timed runs, results in a table.
The hard part (on purpose)
Mechanical problems (loose wheels, a dragging chassis) look like code problems. Test the base driving straight before adding sensors.
When students get stuck
The robot turns the wrong way. Ask: Which motor slows when the sensor sees the line? Fix: Swap the turn logic, or swap a motor's wires.
It resets when it starts. Ask: Where do the motors get their power? Fix: Their own battery, grounds joined.
Stretch and support
Stretch: Proportional steering: slow the inside wheel by an amount that depends on how far off the line it is.
Support: A driver wiring diagram and a two-sensor line-follower sketch to Modify.
Where it leads
Other Years 9–10 projects: Automated sorter, Lift.
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: Choosing the battery against the brief and planning the turn signals before building connects Power and motors to a real design.
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.
Now you can
Choose a battery and motors against a brief.
Plan a robot's steering from its sensors.
Test a robot on a course and evaluate it with data.