BLE protocol notes
==================

The Avea bulb communicates over Bluetooth Low Energy (BLE). The library writes to the Avea control characteristic to set or request state such as color, brightness and name.

UUIDs
-----

The library uses the following Avea-specific UUIDs:

.. list-table::
   :header-rows: 1

   * - Purpose
     - UUID
   * - Avea service
     - ``f815e810-456c-6761-746f-4d756e696368``
   * - Control characteristic
     - ``f815e811-456c-6761-746f-4d756e696368``

Commands
--------

.. list-table::
   :header-rows: 1

   * - Value
     - Command
   * - ``0x35``
     - Set or get bulb color
   * - ``0x57``
     - Set or get bulb brightness
   * - ``0x58``
     - Set or get bulb name

Brightness
----------

Brightness values are integers from ``0`` to ``4095``. The command payload starts with ``0x57`` followed by the brightness value encoded as little-endian bytes.

Color
-----

Color values are 12-bit integers from ``0`` to ``4095``. The color command starts with ``0x35`` and contains values for white, red, green and blue.

The channel prefixes are:

.. list-table::
   :header-rows: 1

   * - Channel
     - Prefix
   * - White
     - ``0x8000``
   * - Red
     - ``0x3000``
   * - Green
     - ``0x2000``
   * - Blue
     - ``0x1000``

The implementation prepares these payloads in :func:`avea.compute_brightness` and :func:`avea.compute_color`.