This library was created to support the Velbus protocol in my home automation efforts.
It is currently being used by the Velbus component in home assisstant but can also be used indepenently.
The latest version of the library is 2.0.12 and it is published as a python package on pypi
I would like to extend this module to support all Velbus modules and offer higher-level functionality such as auto-discovery, so feel free to submit pull requests or log issues through github for functionality you like to have included.
API documentation is available here
The library currently only supports a serial connection to the Velbus controller (either through USB module or through RS-232 interface). In order to use the library, you need to first initialize the controller and can then send and receive messages on the Velbus. The library currently does not validate if a message is supported by a certain module (e.g., you can send a blind up message to a relay)
import velbus
import time
# serial (or USB over serial) device connected to Velbus controller
port = "/dev/ttyACM0"
connection = velbus.VelbusUSBConnection(port)
controller = velbus.Controller(connection)
controller.subscribe(_on_message)
# set module address
module_address = 0xdc
message = velbus.SwitchRelayOnMessage(module_address)
channel_number = 1
message.relay_channels = [channel_number]
controller.send(message)
def _on_message(received_message):
print("Velbus message received")
print(received_message.address)
time.sleep(5)
connection.stop()You can install the library with pip (pip install python-velbus) or by checking out the github repository and running python setup.py install at the root of the repository.
The following Velbus modules are currently supported by this library:
| Module name | Description | Status | Comments |
|---|---|---|---|
| VMB6IN | 6 channel input module | SUPPORTED | All messages are supported |
| VMB7IN | 7 channel input module | SUPPORTED | Only messages from VMB6IN are supported |
| VMB4RYLD | 4 channel relay module | SUPPORTED | All messages are supported |
| VMB4RYNO | 4 channel relay module | SUPPORTED | All messages are supported |
| VMB1RS | Serial interface | SUPPORTED | All messages are supported |
| VMB1USB | USB configuration module | SUPPORTED | All messages are supported |
| VMBRSUSB | Configuration module with USB and RS-232 interface | SUPPORTED | All messages are supported |
The velbus website contains an overview of the different available modules and their protocol documentation. In order to add support for an additional module, read through the protocol documemntation and add support for missing messages (many messages are shared between modules so make sure to check if a message already exists or not)
Steps to add support for an additional module:
- Look up the protocol documentation of the module you want to include at the velbus website: Select the module, go to Downloads and search for the info sheet with protocol information.
- Go through the messages directory and look for messages in the protocol information sheet that are not yet supported. Create a new file in the messages folder for each unsupported message. Every new message should inherit from the Message object and reuse common functionality.
- Implement constructor method for each new message
- Implement the populate and data_to_binary methods for each new message
- If the message has other than low priority or no RTR set (which are defaults), then re-implement set_defaults method
- Add new messages to the init.py file in the messages folder
- Test and iterate
- Update the Supported modules section of the README.md file
- Submit a pull request on Github
The library currently offers only the lowest level of functionality: sending and receiving messages to modules. I plan to extend this library with more higher-level functionality such as:
- Modeling modules and their supported functions as entities
- Only allowing to send supported messages to modules
- Auto-discovery of modules
- Exposing the velbus controller as an external API so it can be shared between different consumers