# Changelog

All notable changes to AR-Autopilot will be documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

---

## [Unreleased]

## [0.1.0-sprint1] — Sprint 1 — Firmware ESP32 base — 2026-05-18

> Sprint 1 was executed autonomously overnight after the user gave explicit
> blanket authorisation (no per-decision approval) to push through subsequent
> sprints. The four technical decisions in `docs/sprint-1-plan.md` §2 were
> taken with the **recommended** option (Arduino-only framework -- pragmatic
> shift from the dual-framework plan, see Architecture note below).

### Added

#### Firmware (`firmware/ar_autopilot_v1/`)

- **`platformio.ini`** — Build configuration for ESP32-DOWD on the
  AR-NMEA-IO v1.0 board. Three envs:
  - `esp32-dev` — release build (-Os, default).
  - `esp32-debug` — debug build (-O0, verbose logs).
  - `native` — host Unity tests (no hardware required, host C++ compiler
    needed).
  - `check` — cppcheck static analysis.
- **Sprint 1 dependencies** pinned: `NMEA2000-library` v4.22+,
  `NMEA2000_esp32` v1.0+, `eModbus` v1.7.4.
- **`src/main.cpp`** — boot, FreeRTOS task spawn, returns to scheduler.
- **`src/system/`** — `ar_log.h` logging facade, `task_config.h` central
  table of stack sizes / priorities / core pinning, `heartbeat.cpp`
  (1 Hz LED + uptime log on Core 0).
- **`src/modes/`** — STANDBY-only mode state machine. Non-STANDBY mode
  requests rejected with a warning.
- **`src/hal/`** — `di_do.{h,cpp}` (5 DI + 10 DO with software debouncing
  and last-state cache); `rudder_sensor.{h,cpp}` (100 Hz ADC + 5-sample
  median filter, Core 1); `rudder_actuator.{h,cpp}` (DO1/DO2/DO3 driver
  with three layered safety interlocks: power-off, STANDBY, limit switch).
- **`src/safety/`** — `watchdog.{h,cpp}` (TWDT @ 2 s, panic on expire);
  `safety_monitor.{h,cpp}` (50 Hz DI polling on Core 1, DI1 disengage
  button enforced, DI4 external alarm, both-limit-switch interlock).
- **`src/protocols/modbus_slave.{h,cpp}`** — eModbus RTU server on UART2
  @ 38400 8N1, slave ID 1. 17 input registers, 19 discrete inputs,
  5 holding registers, 4 coils. Reads pull from live telemetry (mode,
  rudder, NMEA 2000 snapshot, heap). Writes validate range and route to
  the corresponding handler.
- **`src/protocols/nmea2000_consumer.{h,cpp}`** — NMEA 2000 stack open
  with CAN TX=GPIO3 RX=GPIO1, subscribed to PGN 127250 (Heading) and
  PGN 127251 (Rate of Turn). Snapshot exposed via Modbus input registers
  24-26 (heading_deg_x100, rot_dps_x100, heading_age_ms). 5 s staleness
  flag built in for Sprint 6 alarm wiring.
- **`src/filters/median.h`** — Templated `MedianFilter<T, N>` (host
  testable).
- **`modbus_registers.yaml`** — Single source of truth for the Modbus
  register map. 45 entries total.
- **`test/test_median_filter/test_median.cpp`** — 8 Unity tests of the
  median filter (host-side, no Arduino dependency).
- **`tools/modbus_client_test.py`** — manual Modbus client for poking
  the slave from a PC with a USB-RS485 dongle.

#### Cross-cutting

- **`tools/gen_modbus_registers.py`** — YAML -> C++ header + Python
  module code generator with `--check` mode for CI/drift detection.
- **`arautopilot/shared/modbus_register_map.py`** — generated Python
  mirror of the firmware register contract (`Reg` dataclass per entry,
  grouped into `DISCRETES`, `COILS`, `INPUTS`, `HOLDINGS`).
- **`arautopilot/tests/test_modbus_register_map.py`** — 30 tests:
  schema sanity, address uniqueness within group, range bounds,
  spot-checks for critical registers, and **drift detection** that fails
  if anyone edits the YAML without regenerating.
- **`docs/firmware.md`** — firmware operator + integrator guide
  (toolchain, build, flash, expected boot log, troubleshooting,
  Sprint 1 capability matrix).

### Architecture decisions taken

- **Framework**: Arduino-on-ESP32 only (NOT the dual
  Arduino-as-ESP-IDF-component proposed in the Sprint 1 plan). Rationale:
  Arduino-on-ESP32 already provides full FreeRTOS access
  (`xTaskCreatePinnedToCore`, priorities, TWDT, log levels), the dual
  framework is notoriously fragile in PlatformIO, and we hit no
  ESP-IDF-only feature in Sprint 1 scope. OTA-with-rollback and secure
  boot become a real ask in Sprint 8 — at that point we either migrate
  to ESP-IDF or wire the equivalent via Arduino + EspOTA.
- **FreeRTOS core split** as proposed: PID + safety + rudder sensor on
  Core 1 (real-time); NMEA 2000 RX + Modbus + heartbeat on Core 0.
- **Logging**: ESP_LOG via UART0 only, no SD card.

### Verification

- `pio run -e esp32-dev` -> SUCCESS (RAM 6.7 %, Flash 26.5 %, 347 KB).
- `pio run -e esp32-debug` -> SUCCESS.
- `pytest` -> **110 passed** in 0.22 s (80 from Sprint 0 + 30 new).
- `ruff check arautopilot/` -> All checks passed.
- `mypy arautopilot/core library shared` -> Success, 0 issues.
- `pio test -e native` -> deferred: needs host C++ compiler (mingw /
  msvc / clang) on this Windows machine. The Unity test sources compile
  on any standard host once a toolchain is installed.

### Not in Sprint 1 (intentional, per brief §12)

- PID loops (inner/outer).
- True Course / Track Keeping modes.
- Alarm catalogue beyond DI1/DI4 forced disengage.
- Knob driver.
- Studio GUI.
- Dedicated display Flutter app.

## [0.1.0] — Sprint 0 — Foundations — 2026-05-17

## [0.1.0] — Sprint 0 — Foundations — 2026-05-17

### Added

- Repository structure following the layout defined in the project brief (section 11)
- Python package skeleton `arautopilot` with submodules:
  - `core/` — data model (Pydantic v2): modes, alarms, actuator config, PID config,
    vessel config, knob state, project config, IDs
  - `library/` — curated seed: 2 actuator profiles (hydraulic reversible,
    electric DC reversible) and 2 default tunings (yacht motor planeo 30 m, 40 m)
  - `studio/` — empty stubs for Sprint 4
  - `tests/` — pytest suite covering the core data model
- Firmware skeleton: `firmware/ar_autopilot_v1/src/hal/pinout.h` only —
  21 I/O assignment for the AR-NMEA-IO v1.0 board, no functional code yet
- Build configuration:
  - `pyproject.toml` with Pydantic v2, PyYAML, python-dateutil
  - Dev dependencies: pytest, pytest-cov, ruff, mypy
  - Ruff + mypy strict configuration
- `examples/sprint0_demo.py` — end-to-end project creation, save, and reload
- Documentation moved/created:
  - `docs/AR_Autopilot_brief.md` — full project brief
  - `docs/architecture.md` — one-page architecture overview
- `LICENSE.txt` — Proprietary, all rights reserved
- `.gitignore` covering Python, Flutter, PlatformIO, IDEs, Windows artifacts

### Notes

- **No functional firmware**, Studio GUI, or display in this sprint — those
  start in Sprint 1, 4, and 4 respectively.
- The seed PID tunings are **conservative starting values** drawn from
  classical marine control literature (Fossen, Perez). They are explicitly
  **not** the integrator's affinated production values, which remain IP.
- Python ≥3.11 required.