# Component

> Base skill for working with electronic components in this library. Use when adding new component types, manufacturer handlers, or working with MPN (Manufacturer Part Number) operations, BOM entries, or component classification.

- Skill: `majiayu000/component-6` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add majiayu000/component-6`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/component-6/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Web & Frontend
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/majiayu000/component-6

---


# 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

| Class | Purpose |
|-------|---------|
| `ComponentType` | Enum of ~200 component types with passive/semiconductor flags |
| `ComponentManufacturer` | Enum of manufacturers with regex patterns |
| `ManufacturerHandler` | Interface for manufacturer-specific MPN parsing |
| `MPNUtils` | Static utilities for MPN normalization, similarity, type detection |
| `BOMEntry` | Component entry in a bill of materials |

## Adding a New Manufacturer Handler

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

```java
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:

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

## Adding a New Component Type

1. Add to `ComponentType` enum with passive/semiconductor flags:
```java
NEW_TYPE(false, true),  // (isPassive, isSemiconductor)
NEW_TYPE_MANUFACTURER(false, true),
```

2. Update `getBaseType()` switch to map specific types to base:
```java
case NEW_TYPE_INFINEON, NEW_TYPE_ST -> NEW_TYPE;
```

3. Add patterns in relevant manufacturer handlers

## MPN Operations

```java
// 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:
```bash
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

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