imu4helmlog

BNO085 sensor calibration and install-time boat-frame alignment (mount_quat). TRIGGER when the user asks about calibration, mount orientation, "which way is forward", drift, roll/pitch showing wrong values, or installing the sensor on the boat. DO NOT trigger for general BNO085 datasheet questions unrelated to calibration.

IMU and seastate domain reference — quaternions, reference frames, heave estimation, significant wave height, motion metrics that matter for sailing performance analysis. TRIGGER when the user asks what a metric means, why we capture a particular report, how seastate is characterized, or how IMU motion relates to polar performance. DO NOT trigger for BNO085 register-level or install questions (use /calibrate).

Build, upload, and monitor firmware on the ESP32-C3. TRIGGER when the user asks to flash the device, check serial output, build firmware, set up OTA, or debug a build/upload failure. DO NOT trigger for host-side test runs (use /tdd) or for hardware wiring questions (use /hardware).

Hardware reference — BOM, ESP32-C3 pinout, BNO085 wiring, power, enclosure, mounting. TRIGGER when the user asks about wiring, pins, which connector, what board to buy, enclosure, physical install, or "can I use pin X for Y". DO NOT trigger for calibration math (use /calibrate) or firmware build issues (use /flash).

Pre-PR verification for imu4helmlog — host tests, device build, clang-format, docs, risk-tier-appropriate checks. TRIGGER when the user is about to open a PR, asks "am I ready to push", or wants a pre-merge review. DO NOT trigger mid-implementation; use /tdd during development.

Ingest protocol reference between the ESP32-C3 device and the helmlog server — schema, versioning, idempotency, endpoint contract. TRIGGER when adding fields to the sample payload, bumping the schema version, implementing the helmlog-side endpoint, or debugging an ingest round-trip. DO NOT trigger for BNO085 register-level questions (use /calibrate or /domain).

Test-driven development for firmware logic using PlatformIO's native env. TRIGGER when adding or changing code under lib/sampler/, lib/packetizer/, lib/ringbuf/, lib/config/, or any pure-logic C++ in this repo. DO NOT trigger for docs, platformio.ini, scripts, or hardware-only modules (lib/imu/, lib/net/, lib/uploader/) where behavior can't be exercised without a board.