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Services

Architecture
Services

flowchart TB
  subgraph Store["Store"]
    StateSlice[State slice\nstore.services.audio etc.]
  end

  subgraph Service["One service (e.g. 000-audio)"]
    Reducer[reducer.py\nInitAction + actions]
    Setup[setup.py\nregister, async setup]
    Handle[ubo_handle.py\nsubscribe, side effects]
  end

  subgraph Defs["Definitions"]
    Types["store/services/audio.py\nState, Actions, Events"]
  end

  subgraph Thread["Worker thread"]
    Loop[Event loop]
    Handle --> Loop
  end

  Types --> Reducer
  Types --> Handle
  Setup --> Reducer
  Setup --> Handle
  Reducer --> StateSlice
  Handle -->|dispatch| Store
  Store -->|events| Handle

Services are the modular components that own hardware, network, or app logic. Each service has its own state slice in the store, a reducer, and a ubo_handle that subscribes to actions/events and runs in a dedicated worker thread with an async event loop.

What you see

  • Layout — Under ubo_app/services/, services are in numbered folders by priority:
  • 000-* — Hardware (audio, display, keypad)
  • 010-* — Notifications, speech synthesis
  • 020-* — Keyboard
  • 030-* — Network (ethernet, ip, wifi)
  • 040-* — Camera, RGB ring, sensors
  • 050-* — LightDM, RPi Connect, SSH, users, VS Code
  • 080-* — Docker
  • 090-* — Assistant, file system, infrared, speech recognition, web UI
  • Per-service files:
  • State/actions/events — Defined in ubo_app/store/services/<name>.py (e.g. audio, display).
  • Reducer — reducer.py in the service folder (e.g. services/000-audio/reducer.py) handles InitAction and that service’s actions; registered as part of the root reducer.
  • Setup — setup.py runs once at startup: register the reducer, run async setup, subscribe to store events from ubo_handle.
  • ubo_handle.py — Subscribes to actions/events and implements the service behavior (e.g. call hardware, dispatch new actions).
  • Threading — Each service runs in a worker thread. Event handlers are wrapped so they run in that service’s thread/loop, not the main thread.
  • Conventions — Use UBO_ for env vars; ubo: prefix for core notification/icon ids and <service_name>: for service-specific ids. Use create_task from ubo_app.utils.async_ for async work in the service loop.
  • Overview — Architecture summary.
  • Store — How service state is combined.
  • Services (docs) — Per-service documentation (Audio, Display, Keypad, etc.).