casambi-web-controller 0.4.0

Using BLE to control a Casambi-based home lighting system via a web interface.

Casambi Web Controller

This document outlines the local Casambi lighting control system utilizing a web API interface.

System Architecture

The application functions as middleware. It employs the FastAPI framework to convert standard HTTP requests into Casambi network commands. The connection lifecycle and device interactions are managed via the casambi-bt library.

Limitations

The system currently supports only a single Casambi network.

Supported devices are exclusively lighting units capable of dimming.

Requirements

Python

Required libraries: fastapi, uvicorn, CasambiBt

Execution

Execute the main Python script. The terminal will prompt for the Casambi network password. The system will automatically discover the network, establish a connection, and initialize the web server on port 8000.

Logical Bridge Concept

The system introduces the concept of a "Logical Bridge". This is an abstraction layer that maps physical Casambi lighting hardware to virtual nodes.

Instead of hardcoding device-specific commands into external platforms (such as a Matter controller), the Logical Bridge exposes a standardized JSON metadata schema. Each virtual unit within this schema encapsulates its operational events (e.g., turn_on, turn_off, set_level, read_level) with directly executable Python scripts.

This architectural choice ensures high interoperability, allowing any external process with a Python interpreter to dynamically interact with the local HTTP APIs without requiring prior knowledge of the Casambi protocol.

API Endpoints

Get all lights

• URL: /api/lights

• Method: GET

• Description: Retrieves the complete list of available units in the network alongside their current dimmer values.

• Sample Response:

[
  {
      "name": "Ceiling Light",
      "dimmer": 255
  },
  {
      "name": "Desk Lamp",
      "dimmer": 0
  }
]

Get specific light status

• URL: /api/status

• Method: GET

• Parameters:

  • name (string, required): The exact assigned name of the device.

• Description: Retrieves the current dimmer state of a specifically named unit. Returns an HTTP 404 error if the unit is not found.

• Sample Response:

{
  "name": "Ceiling Light",
  "dimmer": 128
}

Control light intensity

• URL: /api/set

• Method: GET

• Parameters:

  • name (string, required): The exact assigned name of the target device.

  • dimmer (integer, required): The target brightness level, strictly constrained between 0 and 255.

• Description: Transmits a command to adjust the target device to the specified dimmer level. Returns a success confirmation. Returns an HTTP 400 error if the dimmer value is invalid.

• Sample Response:

{
  "status": "success"
}

Read or set light level

• URL: /api/level

• Method: GET

• Parameters:

  • name (string, required): The exact assigned name of the target device.

  • dimmer (float, optional): The target brightness level, constrained between 0.0 and 1.0.

• Description: Retrieves the current level if no dimmer parameter is provided. If provided, sets the dimmer level mapped to the hardware range.

• Sample Response:

{
  "status": "success",
  "level": 0.5
}

Get logical bridge metadata

• URL: /api/metadata

• Method: GET

• Description: Dynamically detects the incoming client request context to resolve the host IP and port. It outputs a JSON payload describing the network as a logical bridge. The payload embeds executable Python scripts mapped to standard lighting events (turn_on, turn_off, set_level, read_level) for automated HTTP integration.

• Sample Response:

{
  "bridge": {
    "id": "casambi_bridge_http",
    "type": "dimmable_lighting_controller",
    "network_host": "192.168.1.220",
    "network_port": 8000
  },
  "devices": [
    {
      "node_id": "casambi_ceiling_light",
      "name": "Ceiling Light",
      "hardware_type": "dimmable_light",
      "events": {
        "turn_on": {
          "trigger": "on_off_cluster",
          "script": "import urllib.request\n# Execute GET request to set dimmer to maximum\nurllib.request.urlopen('[http://192.168.1.220:8000/api/level?name=Ceiling%20Light&dimmer=1.0](http://192.168.1.220:8000/api/level?name=Ceiling%20Light&dimmer=1.0)')"
        },
        "turn_off": {
          "trigger": "on_off_cluster",
          "script": "import urllib.request\n# Execute GET request to turn off\nurllib.request.urlopen('[http://192.168.1.220:8000/api/level?name=Ceiling%20Light&dimmer=0.0](http://192.168.1.220:8000/api/level?name=Ceiling%20Light&dimmer=0.0)')"
        },
        "set_level": {
          "trigger": "level_control_cluster",
          "script": "import sys, urllib.request\n# Send logical level directly to the new API\nlogical_level = float(sys.argv[1]) if len(sys.argv) > 1 else 1.0\nurllib.request.urlopen(f'[http://192.168.1.220:8000/api/level?name=Ceiling%20Light&dimmer=](http://192.168.1.220:8000/api/level?name=Ceiling%20Light&dimmer=){logical_level}')"
        },
        "read_level": {
          "trigger": "level_control_cluster",
          "script": "import urllib.request, json\n# Retrieve current level from the new API\nresponse = urllib.request.urlopen('[http://192.168.1.220:8000/api/level?name=Ceiling%20Light](http://192.168.1.220:8000/api/level?name=Ceiling%20Light)')\ndata = json.loads(response.read().decode('utf-8'))\nprint(data.get('level', 0.0))"
        }
      }
    }
  ]
}