similarity-mcu

# MCU Similarity Calculator Skill Guidance for working with MCU similarity calculators in the lib-electronic-components library. --- **For metadata-driven similarity architecture**, see `/similarity-metadata`: - SpecImportance levels (CRITICAL, HIGH, MEDIUM, LOW, OPTIONAL) - ToleranceRule types (exactMatch, percentageTolerance, minimumRequired, etc.) - SimilarityProfile contexts (DESIGN_PHASE, REPLACEMENT, COST_OPTIMIZATION, etc.) - Calculator integration patterns and gotchas --- ## Overview There are two MCU-related calculators: ### MCUSimilarityCalculator (Simple Interface) - Implements `SimilarityCalculator` - Uses pattern matching for family/series/features - No PatternRegistry required ### MicrocontrollerSimilarityCalculator (Component Interface) - Implements `ComponentSimilarityCalculator` - Uses manufacturer handlers for extraction - Requires PatternRegistry ## Applicable Types (MicrocontrollerSimilarityCalculator) ```java ComponentType.MICROCONTROLLER ComponentType.MICROCONTROLLER_ATMEL ComponentType.MICROCONTROLLER_INFINEON ComponentType.MICROCONTROLLER_ST ComponentType.MCU_ATMEL ``` ## Similarity Weights (MCUSimilarityCalculator) ```java familySimilarity * 0.5 // Family is most important seriesSimilarity * 0.3 // Series number featureSimilarity * 0.2 // Feature codes (F, L, U, etc.) ``` ## MCU Families ### Family Groups | Group | Members | |-------|---------| | PIC | PIC16, PIC18, PIC24, PIC32 | | STM | STM8, STM32 | | ATM | ATMEGA, ATTINY, ATXMEGA | | MSP | MSP430, MSP432 | ```java // Same family = 1.0 family similarity calculator.calculateSimilarity("STM32F103", "STM32F407"); // High similarity (same STM32 family) // Related family = 0.8 family similarity calculator.calculateSimilarity("PIC16F877", "PIC18F4550"); // Good similarity (both PIC family) ``` ## Feature Codes | Code | Meaning | |------|---------| | F | Flash memory | | L | Low power | | U | USB capable | | W | Wireless | | R | ROM version | | T | Extended temperature | ```java // Same feature codes contribute to similarity calculator.calculateSimilarity("STM32F103", "STM32F407"); // Both have F (Flash) feature ``` ## Series Similarity Series numbers are compared numerically: - Same series = 1.0 - Close numbers (within 100) = partial similarity - Far numbers = lower similarity ```java // Same series calculator.calculateSimilarity("ATMEGA328", "ATMEGA328P"); // Very high similarity // Close series calculator.calculateSimilarity("ATMEGA328", "ATMEGA329"); // High similarity // Far series calculator.calculateSimilarity("ATMEGA328", "ATMEGA2560"); // Lower similarity ``` ## MicrocontrollerSimilarityCalculator Scoring | Condition | Score | |-----------|-------| | Same manufacturer, same series, same package | 1.0 | | Same manufacturer, same series, different package | 0.9 | | Official replacement parts | 0.8 | | Same series across manufacturers | 0.7 | | Both microcontrollers, different series | 0.5 | ## Test Examples ### MCUSimilarityCalculator ```java // Identical MCU calculator.calculateSimilarity("ATMEGA328P", "ATMEGA328P"); // Returns 1.0 // Same family, different series calculator.calculateSimilarity("STM32F103", "STM32F407"); // Returns > 0.5 // Different families calculator.calculateSimilarity("STM32F103", "ATMEGA328"); // Returns lower similarity ``` ### MicrocontrollerSimilarityCalculator ```java // Same part, different package calculator.calculateSimilarity("ATMEGA328P-AU", "ATMEGA328P-PU", registry); // Returns >= 0.5 // Different MCUs calculator.calculateSimilarity("ATMEGA328P", "STM32F103C8T6", registry); // Returns 0.5 (base MCU similarity) ``` ## Common MCU Patterns ### Atmel/Microchip AVR ``` ATMEGA 328 P -AU │ │ │ │ │ │ │ └── Package (AU=TQFP) │ │ └───── Variant (P=Picopower) │ └───────── Series number └──────────────── Family ``` ### STMicroelectronics STM32 ``` STM32 F 103 C8 T6 │ │ │ │ │ │ │ │ │ └── Package (T6=LQFP48) │ │ │ └───── Memory/pins │ │ └───────── Series │ └─────────── Type (F=Foundation) └───────────────── Family ``` ### Microchip PIC ``` PIC16 F 877 A │ │ │ │ │ │ │ └── Variant │ │ └────── Series │ └──────── Memory type (F=Flash) └────────────── Family ``` --- ## Learnings & Quirks ### Family Detection - Regex `^([A-Z]+)\d+` extracts family prefix - Empty family = 0.0 family similarity ### Series Number Extraction - Extracts first numeric sequence - Compared as integers for proximity ### Feature Code Position - Usually at end of part number - Regex `[A-Z]+$` extracts trailing letters ### Package Codes - Vary significantly by manufacturer - Don't affect core part equivalence - Same MCU in different package = HIGH similarity ### Cross-Family Comparison - Different families get Levenshtein similarity - Never returns > 0.8 for different families <!-- Add new learnings above this line -->