Adding BSB-LAN Parameters

This skill guides you through adding new parameters to the python-bsblan library.

Parameter Naming Conventions

• Use snake_case for all parameter names
• Group related parameters with common prefixes
• Legionella-related parameters use legionellafunction* prefix
• DHW (Domestic Hot Water) parameters use dhw_* prefix

Discovering Parameters from a Real System

Before adding a new parameter, use examples/fetch_param.py to retrieve the raw API response from a real BSB-LAN device. This shows the exact structure, data types, units, and descriptions returned by the device.

Setup

# Set environment variables for your device
export BSBLAN_HOST=<ip-or-host>     # Your BSB-LAN IP address; leave unset to use autodiscovery
export BSBLAN_PASSKEY=your_passkey  # Optional: if your device requires a passkey
export BSBLAN_USER=username         # Optional: if authentication is enabled
export BSBLAN_PASS=password         # Optional: if authentication is enabled
export BSBLAN_PORT=80               # Optional: defaults to 80

Fetching Parameters

# Fetch a single parameter
cd examples && python fetch_param.py 1645

# Fetch multiple parameters at once
cd examples && python fetch_param.py 1645 1641 1642 1644 1646

Example Output

The raw API response shows the exact structure you need to model:

{
  "1645": {
    "name": "Legionella function setpoint",
    "value": "70.0",
    "unit": "°C",
    "desc": "",
    "dataType": 0
  }
}

Use this output to determine:

• Field type: float, int, or str based on the value format
• Unit: The unit field (e.g., °C, %, -)
• Description: The name field for docstrings
• Data type: The dataType field for EntityInfo typing

Device Discovery

fetchparam.py uses mDNS/Zeroconf discovery (via examples/discovery.py) to find your BSB-LAN device automatically when BSBLANHOST is not set. If mDNS is unavailable, set the BSBLAN_HOST environment variable directly.

Steps to Add a New Parameter

1. Add to constants.py

Add the parameter ID mapping:

BASE_HOT_WATER_PARAMS: Final[dict[str, str]] = {
    "1645": "legionella_function_setpoint",  # Parameter ID: name
}

2. Add to Model in models.py

Add the field to the appropriate model:

class HotWaterConfig(BaseModel):
    legionella_function_setpoint: EntityInfo[float] | None = None

3. Update Method in bsblan.py (if settable)

Add parameter to the method signature:

async def set_hot_water(
    self,
    legionella_function_setpoint: float | None = None,
) -> None:

4. Add Tests

Create tests in tests/test_*.py:

@pytest.mark.asyncio
async def test_set_hot_water(mock_bsblan: BSBLAN) -> None:
    """Test setting BSBLAN hot water state."""
    await mock_bsblan.set_hot_water(
        SetHotWaterParam(nominal_setpoint=60.0)
    )
    mock_bsblan._request.assert_awaited_with(
        base_path="/JS",
        data={"Parameter": "1610", "Value": "60.0", "Type": "1"},
    )

Polling Categories

Parameters are organized by update frequency:

• Fast Poll (State): Current temperatures, HVAC action/state, pump states
• Slow Poll (Config): Operating modes, setpoints, legionella settings, time programs
• Static: Device identification, min/max temperature limits

Hot Water Parameter Groups

Hot water parameters use granular lazy loading. When adding a new hot water param, add it to the appropriate group in constants.py:

# In constants.py - add to appropriate group set:
HOT_WATER_ESSENTIAL_PARAMS: Final[set[str]] = {"1600", "1610", ...}
HOT_WATER_CONFIG_PARAMS: Final[set[str]] = {"1601", "1614", ...}

Concurrency Safety

The library uses asyncio locks to prevent race conditions:

• sectionlocks: Per-section locks for lazy loading
• hotwatergrouplocks: Per-group locks for hot water validation

When adding new sections or groups, the lock is created automatically on first access.

Validation

Always run after changes:

uv run prek run --all-files
uv run pytest --cov=src/bsblan --cov-report=term-missing

Coverage requirements: 95%+ total, 100% patch coverage.