# Changelog

All notable changes to the AddVantage PPG firmware and tools.

## [3.4.0] - 08/01/2026

### Added
- **Sphinx documentation system** - Full API docs for firmware and test tools
  - Doxygen/Breathe integration for C code documentation
  - Autodoc for Python test harness modules
  - User guides: CAN protocol, flash layout, telemetry, testing
  - Known issues tracking
- **Cloudflare Pages deployment** - Auto-deploy docs to acu.mikeayles.com
- **CMake docs target** - `ninja docs` to build documentation

### Changed
- Documentation now hosted externally instead of in-repo markdown

## [3.2.7] - 07/01/2026

### Fixed
- **Boot loop issue** - Fixed watchdog timeout during C runtime initialization
  - Added custom reset handler (`startup_wdog.S`) that disables WDOG within 256 bus cycles
  - Device no longer boot loops after flashing

### Added
- **Test harness boot loop detection** - Detects firmware that's stuck in reset cycle
  - Counts version strings (>3 indicates boot loop)
  - Verifies 10+ telemetry lines received (proves stable operation)
- **CAN bus validation** - Compare CAN data to ECU telemetry
  - Statistical comparison (mean, stddev) over 10 second window
  - Configurable tolerance (default 10%)
- **Real-time CAN viewer GUI** - `tools/can_viewer.py`
  - Gauge widgets for RPM, Torque, Temperature
  - Time series graphs with ECU overlay
  - Side-by-side CAN vs ECU comparison

### Changed
- **CMake build system** - Now the recommended build method
  - Vendored SDK dependencies (no CodeWarrior required)
  - Cross-platform (macOS, Linux, Windows)
- **Variables API refactored** - Cleaner shared variable interface

## [3.2.6] - 2025

### Added
- Version string in boot telemetry (`V3.2.6` suffix)
- Semantic versioning format in boot banner

### Fixed
- Telemetry parsing for extended fields

## [3.2.5] - 2023

### Added
- Temperature correction map (100 points, 1°C resolution)
- Differential pressure compensation

### Changed
- Fuel map resolution increased to 16x16

## [3.2.0] - 2023

### Added
- J1939 CAN bus support
  - EEC1 (RPM, Torque)
  - ET1 (Coolant Temperature)
  - LFE (Fuel Economy)
- Multiple fuel map support (4 maps)
- EEPROM emulation in flash

### Changed
- Migrated from ProcessorExpert SCI to MSCAN driver
- Updated baud rate handling

## [3.1.x] - 2022

### Added
- VT100 terminal display mode
- Password protection for configuration
- Engine profile presets (1-18)

### Fixed
- ADC sampling stability
- Serial output buffering

## [3.0.0] - 2022

### Added
- Initial SKEAZ128 port
- Basic PPG control
- UART telemetry output
- Flash configuration storage

---

## Version Numbering

Format: `MAJOR.MINOR.PATCH`

- **MAJOR** - Hardware platform changes
- **MINOR** - Feature additions
- **PATCH** - Bug fixes, minor improvements

## Upgrade Notes

### From 3.2.6 to 3.2.7

No configuration changes required. The watchdog fix is transparent.

**Build Change:** Use CMake instead of CodeWarrior:

```bash
mkdir build && cd build
cmake -G Ninja -DCMAKE_TOOLCHAIN_FILE=../arm-gcc-toolchain.cmake ..
ninja
```

### From 3.1.x to 3.2.x

Configuration flash layout changed. Run factory reset (`f` command) after upgrade.

### From 3.0.x to 3.1.x

Compatible upgrade. No changes required.