From requirements to a bill of materials
A custom circuit is really several library blocks, chosen and combined to hit your requirements. You describe the whole product — with its constraints — and Forge assembles the BOM. Your job is to direct and review, not to accept blindly.
Give Forge the full picture in one description:
- the inputs (which sensors, what they measure),
- the brain (does it need Wi-Fi? Bluetooth? just local logic?),
- the outputs (screen, LEDs, motor, buzzer),
- the power (battery + runtime, or plugged in),
- and the cost target in naira.
The more of your requirements you state, the more the first BOM already fits. Then you read it critically: is every part pulling its weight? Is anything missing? Is the power path right for the runtime? Is it within budget?
That review — not the generation — is the skill. A BOM is a strong first draft to interrogate, not a final answer to trust.
Power budgeting and honest trade-offs
Two custom-circuit skills separate a design that works on paper from one that works in the field.
Power budgeting
A battery product lives or dies on its power budget. The idea is simple: add up how much current each part draws, and multiply by how long it must run.
battery capacity ≈ total current × runtime (plus margin)
A Wi-Fi node that transmits often draws far more than one that sleeps most of the time. If the battery is too big or too expensive, you have levers: sleep the controller between readings, report less often, or use a lower-power radio. Naming your runtime ("about a week") lets Forge size the battery and pick a power path that can actually hit it.
Honest trade-offs
When the BOM overshoots the cost or size target, you trade, deliberately:
- swap a part for a cheaper one that's good enough,
- drop a non-essential feature,
- or accept a limit (shorter runtime, smaller screen) on purpose.
Good product development is a series of conscious trade-offs — not pretending there are none.
Your custom node must run for a week on a battery. What mainly determines the battery capacity you need?
Try it — a multi-sensor IoT node on a budget
Design a real custom circuit with constraints, then interrogate the result.
Send the prompt — an outdoor sensor node with three sensors, Wi-Fi, a week of runtime, and a naira budget — and read the BOM critically:
- Is every part needed, or could one be dropped?
- Does the power path (battery + charging + converter) suit a week of runtime?
- Is the total within the target price?
Where would you substitute or cut to hit the budget? That judgement is the advanced skill.
Read the BOM Forge returns critically: is every part needed? Does the power path suit a week of runtime? Is it within budget? Note where you'd substitute or cut to hit the target.
A battery-powered outdoor sensor node that reports temperature, humidity, and soil moisture over Wi-Fi, runs for about a week per charge, target around 18,000 NGN.
Opens in a new tab so you keep this lesson open. Nothing to buy — this is just to see how Forge reasons. This step isn't graded.