Electronic Component Skill

This skill provides guidance for working with electronic components in the lib-electronic-components library.

Core Concepts

Component Type Hierarchy

Components are classified using ComponentType enum with two levels:

• Base types: RESISTOR, CAPACITOR, MOSFET, OPAMP, etc.
• Manufacturer-specific types: MOSFET_INFINEON, CAPACITOR_CERAMIC_MURATA, etc.

Use getBaseType() to map specific types to their base type.

Key Classes

Adding a New Manufacturer Handler

1. Create handler in src/main/java/no/cantara/electronic/component/lib/manufacturers/:

public class NewMfrHandler implements ManufacturerHandler {
    @Override
    public void initializePatterns(PatternRegistry registry) {
        registry.registerPattern(ComponentType.RESISTOR,
            Pattern.compile("^NMF[0-9]{4}.*", Pattern.CASE_INSENSITIVE));
    }

    @Override
    public String extractPackageCode(String mpn) { /* ... */ }

    @Override
    public String extractSeries(String mpn) { /* ... */ }

    @Override
    public boolean isOfficialReplacement(String mpn1, String mpn2) { return false; }

    @Override
    public Set<ManufacturerComponentType> getManufacturerTypes() { return Set.of(); }

    @Override
    public Set<ComponentType> getSupportedTypes() {
        return Set.of(ComponentType.RESISTOR);
    }
}

2. Add entry to ComponentManufacturer enum:

NEW_MFR("(?:NMF)[0-9]", "New Manufacturer", new NewMfrHandler()),

Adding a New Component Type

1. Add to ComponentType enum with passive/semiconductor flags:

NEW_TYPE(false, true),  // (isPassive, isSemiconductor)
NEW_TYPE_MANUFACTURER(false, true),

2. Update getBaseType() switch to map specific types to base:

case NEW_TYPE_INFINEON, NEW_TYPE_ST -> NEW_TYPE;

3. Add patterns in relevant manufacturer handlers

MPN Operations

// Normalize MPN
String normalized = MPNUtils.normalize("LM358-N"); // "LM358N"

// Detect manufacturer
ComponentManufacturer mfr = ComponentManufacturer.fromMPN("STM32F103C8T6");

// Detect component type
ComponentType type = ComponentType.fromMPN("IRF540N"); // MOSFET

// Calculate similarity
double sim = MPNUtils.calculateSimilarity("LM358", "MC1458"); // 0.9

Similarity Calculators

Each component type can have a dedicated similarity calculator in componentsimilaritycalculators/:

• ResistorSimilarityCalculator - compares resistance values, tolerances, packages
• CapacitorSimilarityCalculator - compares capacitance, voltage, dielectric
• MosfetSimilarityCalculator - compares Vds, Rds(on), package
• etc.

Implement ComponentSimilarityCalculator interface and add to list in MPNUtils.

Testing

Run component-related tests:

mvn test -Dtest=MPNUtilsTest
mvn test -Dtest=ComponentTypeDetectorTest
mvn test -Dtest=MPNExtractionTest

Related Skills

Use specialized skills for specific component types:

• /resistor - Resistor patterns and value extraction
• /capacitor - Capacitor patterns and specifications
• /semiconductor - Diodes, transistors, MOSFETs
• /ic - Microcontrollers, op-amps, voltage regulators
• /connector - Connector manufacturer patterns
• /memory - Flash, EEPROM, RAM components

Recording Learnings

Important: When you discover quirks, edge cases, or important patterns while working on components:

1. General/cross-cutting learnings → Add to CLAUDE.md under "Learnings & Quirks"
2. Component-specific learnings → Add to the relevant skill file below

Examples of what to record:

• MPN patterns that don't follow expected conventions
• Manufacturer-specific quirks in part numbering
• Edge cases in similarity calculation
• Test failures that revealed unexpected behavior
• Regex patterns that needed adjustment

Learnings & Quirks

Handler Patterns

• Use registry.addPattern() not registry.registerPattern() - the latter requires a compiled Pattern object
• Handler order in ComponentManufacturer enum affects detection priority for ambiguous MPNs

MPN Edge Cases

• Some MPNs contain hyphens that are significant (e.g., Molex 43045-0212) vs decorative (e.g., LM358-N)
• Yageo resistors: RC0603FR-0710KL - the -07 is TCR code, not a separator