v2.4.0 - Live Recalibration, Adaptive Threshold & PCA

[francescopace]

Highlights

• Two detection algorithms: Choose between MVS (default) and PCA (Principal Component Analysis)
• Recalibrate from Home Assistant: New switch to trigger recalibration without reflashing
• Adaptive threshold by default: No manual tuning needed - works out of the box

New Features

Dual Detection Algorithms

Two motion detection algorithms are now available:

Algorithm	Configuration
MVS (default)	detection_algorithm: mvs
PCA (experimental)	detection_algorithm: pca

Calibrate Switch

New Home Assistant switch for triggering recalibration without reflashing:

• switch.espectre_calibrate: Turn ON to recalibrate, auto-turns OFF when complete
• Useful after room layout changes or furniture moves

Adaptive Threshold

The segmentation_threshold parameter is now optional:

• Default: Adaptive threshold calculated as P95 × 1.4 during calibration
• Manual override: Specify value in YAML to use fixed threshold

Improvements

Dual Band Selection Algorithms

Two automatic subcarrier selection algorithms:

Algorithm	Method	Configuration
NBVI (default)	12 non-consecutive subcarriers	segmentation_calibration: nbvi
P95	12 consecutive subcarriers	segmentation_calibration: p95

HT20-Only Mode

Simplified to WiFi 4 (802.11n) HT20 mode for stable 64 subcarriers across all ESP32 variants:

• Consistent performance on C3, C6, S3, and original ESP32
• Reduced memory footprint

Other Improvements

• Lower threshold minimum: 0.1 (was 0.5) for high-sensitivity applications
• ESP32-C3 dev config: Added espectre-c3-dev.yaml

Bug Fixes

• ESP32-C3 boot crash: Fixed duplicate register_component calls
• USB Serial JTAG: Correct ESPHome macro for detection
• CSI data overflow: Limit to 128 bytes to prevent overflow

Micro-ESPectre (R&D Platform)

• SHA256 firmware verification: New verify command detects outdated firmware
• CSI Stream Protocol v2: Auto-detected chip type, contributor tracking
• Refactored calibrators: Cleaner architecture with p95_calibrator.py, nbvi_calibrator.py, threshold.py

For Contributors

Architecture changes, testing, and CI/CD improvements

Architecture

• New IDetector interface for polymorphic detection (MVSDetector, PCADetector)
• Centralized threshold calculation in threshold.h / threshold.py
• Legacy csi_processor module removed

Multi-Chip Test Suite

Tests run on ESP32-C6 and ESP32-S3 with real CSI data:

Chip	Recall	FP Rate	F1-Score
C6	98.8%	0.0%	99.4%
S3	99.1%	14.3%	92.9%

CI/CD

• NPZ data loading: C++ tests use same NPZ files as Python via cnpy
• QEMU smoke tests: Catches crashes on S3, C3, C6 before deploy
• Stale bot: Auto-close inactive issues after 30+7 days
• Coverage threshold: CI fails below 80%

Documentation

• Roadmap update: Added 3D Localization in v4.x (30-50cm indoor tracking with phase-coherent antenna array)
• Added Part 2 Medium article link to README
• Updated bug report template with crash debug section
• Added Home Assistant dashboard screenshot to README

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This discussion was created from the release v2.4.0 - Live Recalibration, Adaptive Threshold & PCA.