EDA Architect Skill

Define the architecture and constraints for electronics projects.

Auto-Activation Triggers

This skill activates when:

• User asks to "design a board", "create a project", "start a new PCB"

• User asks "what do I need for..." an electronics project

• Project has no docs/project-spec.md or docs/design-constraints.json

• User mentions requirements gathering or project planning

Context Requirements

Requires: Nothing (this is the first step)

Produces:

• docs/project-spec.md

• Human-readable specification

• docs/design-constraints.json

• Machine-readable constraints

Workflow

1. Understand the Project Goal

Ask the user about:

• What is this device/board intended to do?

• Target use case (prototype, production, hobby)?

• Any existing designs to reference?

2. Define Power Architecture

Determine:

• Input power source (USB, battery, mains, PoE, solar)

• Voltage rails needed (3.3V, 5V, 12V, etc.)

• Power topology per rail: LDO vs buck converter

• See reference/POWER-TOPOLOGY-DECISION.md for decision tree

• Estimated power budget

• Battery life requirements if applicable

2.5 Thermal Budget

Estimate early:

• Total power dissipation (sum of all consumers)

• Hot components (any >0.5W needs attention)

• Cooling strategy: natural, forced, heatsink

• See reference/THERMAL-BUDGET.md for estimation guide

3. Processing Requirements

Establish:

• MCU/processor needs (or if needed at all)

• Processing requirements (speed, peripherals)

• Memory requirements (Flash, RAM)

• Preferred families (STM32, ESP32, RP2040, etc.)

4. Connectivity & Interfaces

Document:

• Wireless: WiFi, Bluetooth, LoRa, Zigbee, cellular

• Wired: Ethernet, USB, CAN, RS485, RS232

• User interfaces: buttons, LEDs, displays

• Debug/programming interfaces

4.5 Stackup Decision

Determine layer count based on complexity:

• 2-layer: Simple, LDO only, low-speed (I2C/SPI)

• 4-layer: MCU with switching regulator, USB, Ethernet, WiFi

• 6-layer: High-speed (>100MHz), DDR, dense routing

• See reference/LAYER-COUNT-DECISION.md for decision tree

5. Sensors & I/O

List:

• Required sensors

• Analog inputs/outputs

• Digital I/O requirements

• Any specialized interfaces (motor control, etc.)

6. Physical Constraints

Define:

• Target board dimensions

• Enclosure requirements

• Mounting hole positions

• Connector placement constraints

• Height restrictions

7. Environmental

Note:

• Operating temperature range

• Indoor/outdoor use

• IP rating if applicable

8. Manufacturing Targets

Capture:

• Target quantity

• Assembly method (hand, reflow, turnkey)

• Layer count preference

• Budget constraints

8.5 DFM Early Constraints

Capture manufacturer capabilities:

• Preferred manufacturer (JLCPCB, PCBWay, OSHPark)

• Assembly method constraints

• Fine-pitch components (affects hand soldering)

• Budget tier: prototype, low-volume, production

Output Format

project-spec.md Structure

Project Specification: [Name]

Overview

[Brief description and goals]

Requirements Summary

Detailed Requirements

[Sections for each category with full details]

Constraints

[Physical, environmental, budget constraints]

Open Questions

[Any unresolved items]

design-constraints.json Schema

See reference/CONSTRAINT-SCHEMA.md for full schema documentation.

Guidelines

• Ask clarifying questions rather than assuming

• Suggest common solutions when user is unsure

• Flag potential issues early (power budget, space constraints)

• Keep the spec focused - avoid scope creep

• Document rationale for key decisions

• Use project templates from reference/PROJECT-TEMPLATES.md as starting points

Architecture Validation Warnings

Before completing the architecture phase, check for these risky combinations:

Condition Warning

2-layer + switching regulator "Consider 4-layer - switching regulators need solid ground plane"

2-layer + USB/Ethernet "Controlled impedance difficult on 2-layer - consider 4-layer"

2W total + no thermal plan "Add thermal budget - high power needs planning"

Hand assembly + fine-pitch (<0.5mm) "Verify solderability - fine-pitch is difficult to hand solder"

0.5W component + no thermal strategy "Component dissipating >0.5W needs thermal attention"

Battery + LDO with high Vin-Vout "Consider buck converter for battery life"

When a warning condition is detected, present it to the user and ask if they want to:

• Update the design to address it

• Acknowledge the risk and proceed

Next Steps

After completing architecture, suggest:

• /eda-source [component-role] to begin component selection

• Start with critical components: MCU, power regulators