Runtime concepts

The Embedded32 runtime layer (@embedded32/core, @embedded32/supervisor) models a small embedded application: periodic tasks, a message bus, and pluggable modules supervised at process level.

Mental model

flowchart LR
  subgraph process [Node.js process]
    SUP[Supervisor]
    RT[Runtime]
    MB[MessageBus]
    MOD1[Module A]
    MOD2[Module B]
    SCH[Scheduler]
  end
  SUP --> RT
  RT --> SCH
  RT --> MB
  MOD1 --> MB
  MOD2 --> MB
  SCH --> MOD1
  SCH --> MOD2

Runtime - owns the scheduler and message bus; wires modules together.
Module - unit of logic with init, start, stop, and optional tick handlers.
MessageBus - in-process pub/sub for typed or string topics.
Supervisor - loads configuration, starts/stops modules, integrates CAN/bridge modules.

Scheduler

The scheduler runs registered callbacks on a fixed interval (milliseconds). Typical uses:

Poll sensors or simulated ECU state
Emit heartbeat messages
Drive simulation ticks

sequenceDiagram
  participant SCH as Scheduler
  participant MOD as Module
  loop every intervalMs
    SCH->>MOD: onTick()
    MOD->>MOD: update state / emit bus event
  end

Message bus

Modules communicate without direct references:

flowchart TB
  PUB[Publisher module]
  BUS[MessageBus]
  SUB1[Subscriber 1]
  SUB2[Subscriber 2]
  PUB -->|publish topic| BUS
  BUS --> SUB1
  BUS --> SUB2

This mirrors ECU-internal event routing and keeps lab code decoupled.

Supervisor and CLI

@embedded32/cli is the primary entry for running a configured stack:

npx embedded32 demo
npx embedded32 start --config ./my-config.json

The supervisor reads JSON configuration (modules, CAN interfaces, bridge endpoints) and coordinates lifecycle: initialize → start → graceful shutdown on SIGINT.

When to use core vs sim vs tools

Need	Package
Custom app with your own modules	`@embedded32/core`
Pre-built vehicle ECU actors	`@embedded32/sim`
Terminal lab without writing code	`@embedded32/tools`
Production-like process layout	`@embedded32/supervisor` + `@embedded32/cli`

Limitations (educational scope)

Single-process Node.js - not a real RTOS or AUTOSAR runtime
No hard real-time guarantees
Configuration format may evolve before v1.1