Metadata-Version: 2.1
Name: avea
Version: 1.5.2
Summary: Control an Elgato Avea bulb using python3
Home-page: https://github.com/k0rventen/avea
Author: k0rventen
License: MIT
Description: # Control of an Elgato Avea bulb using Python
        
        [![PyPI](https://img.shields.io/pypi/v/avea.svg)](https://pypi.org/project/avea/)
        [![Language grade: Python](https://img.shields.io/lgtm/grade/python/g/k0rventen/avea.svg?)](https://lgtm.com/projects/g/k0rventen/avea/context:python)
        [![Build Status](https://travis-ci.com/k0rventen/avea.svg?branch=master)](https://travis-ci.com/k0rventen/avea)
        
        
        The [Avea bulb from Elgato](https://www.amazon.co.uk/Elgato-Avea-Dynamic-Light-Android-Smartphone/dp/B00O4EZ11Q) is a light bulb that connects to an iPhone or Android app via Bluetooth.
        
        This project aim to control it using a Bluetooth 4.0 compatible device and some Python magic.
        
        Tested on Raspberry Pi 3 and Zero W (with integrated bluetooth). 
        
        - [Control of an Elgato Avea bulb using Python](#control-of-an-elgato-avea-bulb-using-python)
          - [TL;DR](#tldr)
          - [Library usage](#library-usage)
          - [Code documentation](#code-documentation)
          - [Reverse engineering of the bulb](#reverse-engineering-of-the-bulb)
          - [Communication protocol](#communication-protocol)
            - [Intro](#intro)
            - [Commands and payload explanation](#commands-and-payload-explanation)
            - [Color command](#color-command)
            - [Brightness command](#brightness-command)
          - [Walkthrough & Example](#walkthrough--example)
            - [Brightness](#brightness)
              - [Color](#color)
          - [Python implementation](#python-implementation)
            - [One-liner for color computation](#one-liner-for-color-computation)
            - [Bluepy writeCharacteristic() overwrite](#bluepy-writecharacteristic-overwrite)
            - [Working with notifications using Bluepy](#working-with-notifications-using-bluepy)
          - [TODO](#todo)
        
        ## TL;DR
        
        The lib requires [bluepy](https://github.com/IanHarvey/bluepy), so we must install the following dependancy, wheter we use pip or install from source.
        
        **Dependancies**
        
        ```
        sudo apt install libglib2.0-dev
        ```
        
        **Then install from pip3**
        
        ```bash
        sudo apt install python3-pip
        sudo pip3 install --upgrade avea
        ```
        
        **or if you prefer installing from source**
        
        ```bash
        git clone https://github.com/k0rventen/avea
        cd avea
        sudo python3 setup.py install
        ```
        
        ## Library usage
        
        You can check the example script `example.py`, to try it directly onto your bulbs :
        
        ```bash
        sudo python3 example.py
        ```
        
        Below is a quick how-to of the various methods of the library.
        
        **Note : the discover\_avea\_bulbs() function needs root privileges, due to bluepy's scan(). From your user, you can use sudo -E.**
        
        ```python
        import avea # Important !
        
        # Get nearby bulbs in a list, then retrieve the name of all bulbs
        # using this method requires root privileges (because of bluepy's scan() )
        nearbyBulbs = avea.discover_avea_bulbs()
        for bulb in nearbyBulbs:
            bulb.get_name()
            print(bulb.name)
        
        # Or create a bulb if you know its address (after a scan for example)
        myBulb = avea.Bulb("xx:xx:xx:xx:xx:xx")
        
        # You can set the brightness, color and name
        myBulb.set_brightness(2000)                 # ranges from 0 to 4095
        myBulb.set_color(0,4095,0,0)                # in order : white, red, green, blue
        myBulb.set_rgb(0,255,0)                     # RGB compliant function
        myBulb.set_smooth_transition(255,255,0,4,30)   # change to rgb(255,255,0) in 4s with 30 iterations per second
        myBulb.set_name("bedroom")                  # new name of the bulb
        
        # And get the brightness, color and name
        print(myBulb.get_name())                # Query the name of the bulb
        theColor = myBulb.get_color()           # Query the current color
        theRgbColor = myBulb.get_rgb()          # Query the bulb in a RGB format
        theBrightness = myBulb.get_brightness() # query the current brightness
        theAddr = myBulb.addr                   # query the bulb Bluetooth addr
        theFwVersion = myBulb.get_fw_version()  # query the bulb firmware version
        ```
        
        That's it. Pretty simple.
        
        Check the explanations below for more informations, or check the sources !
        
        
        ## Code documentation
        
        ## Reverse engineering of the bulb
        
        I've used the informations given by [Marmelatze](https://github.com/Marmelatze/avea_bulb) as well as some reverse engineering using a `btsnoop_hci.log` file from an Android device and Wireshark.
        
        Below is a pretty thorough explanation of the BLE communication and the python implementation to communicate with the bulb.
        
        As BLE communication is quite complicated, you might want to skip all of this if you just want to use the library. But it's quite interesting.
        
        
        ## Communication protocol
        
        ### Intro
        
        To communicate the bulb uses Bluetooth 4.0 "BLE", which provide some interesting features for communications, to learn more about it go [here](https://learn.adafruit.com/introduction-to-bluetooth-low-energy/gatt).
        
        To sum up, the bulb emits a set of `services` which have `characteristics`. We use the latter to communicate to the device.
        
        The bulb uses the service `f815e810456c6761746f4d756e696368` and the associated characteristic `f815e811456c6761746f4d756e696368` to send and receive informations about its state (color, name and brightness). We'll transmit over this characteristic.
        
        ### Commands and payload explanation
        
        The first bytes of transmission is the command. A few commands are available :
        
        Value | Command
        --- | ---
        0x35 | set / get bulb color
        0x57 | set / get bulb brightness
        0x58 | set / get bulb name
        
        ### Color command
        
        For the color command, the transmission payload is as follows :
        
        Command | Fading time | Useless byte | White value | Red value | Green value | Blue value
        ---|---|---|---|---|---|---
        
        Each value of the payload is a 4 hexadecimal value. (The actual values are integers between 0 and 4095)
        
        For each color, a prefix in the hexadecimal value is needed :
        
        Color | prefix
        ---|---
        White| 0x8000
        Red | 0x3000
        Green | 0x2000
        Blue | 0X1000
        
        The values are then formatted in **big-endian** format :
        
        Int | 4-bytes Hexadecimal | Big-endian hex
        ---|---|---
        4095 | 0x0fff| **0xff0f**
        
        ### Brightness command
        
        The brightness is also an Int value between 0 and 4095, sent as a big-endian 4-bytes hex value. The transmission looks like this :
        
        Command | Brightness value |
        ---|---
        0x57 | 0xff00
        
        ## Walkthrough & Example
        
        Let say we want the bulb to be pink at 75% brightness :
        
        ### Brightness
        
        75% brightness is roughly 3072 (out of the maximum 4095):
        
        Int | 4-bytes Hexadecimal | **Big-endian hex**
        ---|---|---
        3072 |0x0C00| **0x000C**
        
        The brightness command will be `0x57000C`
        
        #### Color
        
        Pink is 100% red, 100% blue, no green. (We assume that the white value is also 0.) For each color, we convert the int value to hexadecimal, then we apply the prefix, then we convert to big-endian :
        
        Variables | Int Values | Hexadecimal values | Bitwise XOR | Big-endian values
        ---|---|---|---|---
        White| 0| 0x0000| 0x8000| 0x0080
        Red | 4095| 0x0fff| 0x3fff| 0xff3f
        Green | 0 | 0x0000| 0x2000 | 0x0020
        Blue | 4095| 0x0fff | 0x1fff| 0xff1f
        
        
        The final byte sequence for a pink bulb will be :
        
        Command | Fading time | Useless byte | White value | Red value | Green value | Blue value
        ---|---|---|---|---|---|---
        `0x35`|`1101`| `0000`| `0080`|`ff3f`|`0020`|`ff1f`
        
        
        ## Python implementation
        Below is some python3 code regarding various aspects that are quite interesting.
        
        ### One-liner for color computation
        To compute the correct values for each color, I created the following conversion (here showing for white) :
        
        ```python
        white = (int(<value>) | int(0x8000)).to_bytes(2, byteorder='little').hex()
        ```
        
        ### Bluepy writeCharacteristic() overwrite
        By default, the btle.Peripheral() object of bluepy only allows to send UTF-8 encoded strings, which are internally converted to hexadecimal. As we craft our own hexadecimal payload, we need to bypass this behavior. A child class of Peripheral() is created and overwrites the writeCharacteristic() method, as follows :
        
        ```python
        class AveaPeripheral(bluepy.btle.Peripheral):
            def writeCharacteristic(self, handle, val, withResponse=True):
                cmd = "wrr" if withResponse else "wr"
                self._writeCmd("%s %X %s\n" % (cmd, handle, val))
                return self._getResp('wr')
        ```
        
        ### Working with notifications using Bluepy
        To reply to our packets, the bulb is using BLE notifications, and some setup is required to be able to receive these notifications with bluepy.
        
        To subscribe to the bulb's notifications, we must send a "0100" to the BLE handle which is just after the one used for communication. As we use handle 0x0028 (40 for bluepy) to communicate, we will send the notification payload to the handle 0x0029 (so 41 for bluepy)
        
        ```python
        self.bulb.writeCharacteristic(41, "0100")
        ```
        After that, we will receive notifications from the bulb.
        
        ## TODO
        - Reverse engineer the `ambiances` (which are mood-based scenes).
        
Platform: UNKNOWN
Classifier: Programming Language :: Python :: 3
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: POSIX :: Linux
Description-Content-Type: text/markdown
