EC-19.2 From a Need to a Requirement, and the Block Diagram
You can turn a vague description of a need into requirements somebody else could test, and draw the block diagram that follows from them.
Before:nothing requiredUnlocks:PE1-4. Embedded C ProgrammingEC-13. Laboratory Practice, in Sequence
The engineering design course later does this formally, with acceptance criteria and a written specification. This topic does it once, informally, on a single page, because a reader who has never written a requirement cannot see what the formal version is protecting them from. The rule to carry forward is that a requirement nobody can test is a wish, and a wish will be interpreted differently by every person who reads it.
Work through these
Hearing a need, and the questions that turn it into a statement
People describe what they want in terms of the solution they imagined rather than the problem they have. A few careful questions about when, how often and what happens otherwise usually reveal a different problem underneath.
NPTEL: Design Thinking — A Primer (IIT Madras) · CourseWhat makes a requirement testable, and what makes one useless
A requirement with a number and a condition can be checked by someone who was not in the room. One that says a thing should be fast or reliable cannot be checked at all, and it will be read differently by everyone.
NPTEL: Product Design and Development (IIT Roorkee) · CourseConstraints: cost, size, power, time and what you can actually obtain
A constraint is a boundary the solution has to stay inside rather than a goal to move towards. Component availability belongs on this list, because a design built around a part nobody stocks is not a design.
NPTEL: Product Design and Development (IIT Roorkee) · CourseThe block diagram, and what each arrow between blocks carries
Boxes name the functions and arrows name what moves between them, which may be a voltage, a message or energy. Labelling the arrows is what turns a decorative drawing into a document somebody can build from.
Comparing two arrangements of the same blocks
The same set of functions can usually be connected in more than one way, and the arrangements differ in cost, complexity and how they fail. Drawing both before choosing is cheaper than discovering the difference during assembly.
NPTEL: Product Design and Development (IIT Roorkee) · CourseWriting the one-page brief for a small build
One page holds the need, the requirements, the constraints and the diagram, and it is what you check the finished thing against. Writing it before building is what makes the later comparison meaningful rather than flattering.
NPTEL: Design Thinking — A Primer (IIT Madras) · Course
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