Pipoco — a minimal Rust ECU

Pipoco is a small Rust ECU workspace built around no_std-compatible runtime crates. The split crates own trigger decoding, scheduling, board interfaces, TunerStudio protocol/page DTOs, and fuel/runtime strategy; ecu-compat remains a legacy compatibility facade for EcuState, TS page-store glue, trigger primitives, and safety helpers. Board crates wire those reusable pieces to pins, ADC, timers, persistence, and transport.

Status: prototype with a verified runtime inventory. The live path currently covers trigger decoding, scheduler execution, safety gating, and base injector pulse-width lookup; several advertised control features remain built but not wired.

Highlights

• 60‑2 trigger decoder with sync/loss handling
• Batch and sequential fuel injection; wasted‑spark and sequential ignition
• Angle‑based scheduling (per‑cylinder TDC + BTDC targets); low‑jitter tick deadlines
• TunerStudio pages for tables, calibration, and runtime diagnostics
• no_std-compatible crates with fixed-size data and integer math; board and runtime responsibilities are split by crate

Getting Started

• Run the verification script:

  • ./tools/verify.sh
  • It runs the lint-clean core checks plus the currently supported STM32F4 build slices.
  • Workspace-wide cargo check --workspace --all-targets --all-features is not a stable gate because the embedded board crates pull incompatible critical-section restore-state modes into one resolution, and the RP2040 example bins are still under active repair.

• Choose a firmware recipe before building or flashing:

  • List renderable board/recipe pairs: cargo run -p ecu-firmware-resolver -- --list
  • Render a build command: cargo run -p ecu-firmware-resolver -- rp2040-pico ignition-only-wasted-spark-no-watchdog-bringup
  • Render a flash command when metadata supports it: cargo run -p ecu-firmware-resolver -- --flash-command rp2040-pico ignition-only-wasted-spark-no-watchdog-bringup

• Manual board package builds are still useful for board bring-up:

  • RP2040 Pico: cargo build -p ecu-rp2040-pico --release
  • STM32F4: rustup target add thumbv7em-none-eabihf && cargo build -p stm32f4-ecu --release

See per-board docs for pins and features: boards/rp2040-pico/TS-HOWTO.md and the board README files.

Feature/Profile Matrix

• stm32f4-ecu: capture-tim and capture-gpio are mutually exclusive capture profiles.
• ecu-rp2350b: capture-gpio is the available capture profile; example-bins gates the helper binaries (capture-pio was removed).
• ecu-rp2040-pico: flash-kv, capture-pio, capture-cam, and example-bins are documented as named feature slices, with the example binaries gated where required.
• Keep the board READMEs and tools/verify.sh in sync when a feature profile is added or removed.

Board Status

• boards/rp2040-pico: bring-up board with live TunerStudio runtime data and flash-backed page persistence.
• boards/stm32f4: bring-up board with timer capture and example transport bins.
• boards/rp2350b: example-only / experimental VE demo and auxiliary bins; not a supported ECU board yet.

TunerStudio Integration

• INI asset used by tests: crates/compat/tests/assets/IPW-ECU.ini (signature “IPW‑ECU V0.1”).
• Pages in use:
  • [Sensors] (3): TPS/MAP calibration, CLT/IAT curves
  • [AE] (4): accel-response calibration and decay/lockout settings
  • [DFCO] (5): thresholds, delays, hysteresis
  • [Limits] (6): sensor clamps and optional emergency triggers
  • [Diag] (7): fault flags; [DiagLog] (8): recent events
  • [Angles] (9): per‑cylinder injection/spark references and cam timeout

Scheduling Modes

• Angle-based scheduling using live tooth timing with per-cylinder angles is the only implemented path.

Persistence

• Tables and angles persist via a simple key/value interface (RAM or flash‑backed on boards).
• Keys: fuel (512 B), ign (512 B), angles (68 B). Flash backends include CRC/versioning.

Safety & Diagnostics

• Sensor range clamps with optional emergency mode
• Flood‑clear and sync‑loss shutdown utilities
• Diagnostics flags and recent‑event log available via TS pages

Project Layout

pipoco/
├── crates/              # Reusable ECU libraries
│   ├── compat/          # Legacy compatibility facade (no_std-compatible)
│   ├── domain/          # Units, ids, authority, and shared domain types
│   ├── runtime/         # Runtime orchestration
│   └── spec/            # Executable specs and formal/proof artifacts
├── boards/              # Embedded board support packages
│   ├── common/          # Shared board adapters and helpers
│   ├── rp2040-pico/     # Pico board
│   ├── rp2350b/         # RP2350B board
│   └── stm32f4/         # STM32F4 board
├── sim/                 # Simulator, FFI, and host driver crates
├── tools/               # Verification and maintenance scripts
└── tests/               # Python/tooling tests

Contributing

• Run ./tools/verify.sh before review.
• Host-side tests: cargo test --workspace --all-features --exclude ecu-rp2040-pico --exclude stm32f4-ecu --exclude ecu-rp2350b.
• Keep no_std-compatible crates on fixed-size data structures. Avoid panics.
• When touching TunerStudio, keep INI/page sizes in sync (tests verify signature and sizes).

License

AGPL-3.0-or-later