Python 3 package for connecting devices to WolkAbout IoT Platform through WolkGateway.
This package is meant to be used for developing WolkGateway modules that enable devices without IP connectivity to send their data to WolkAbout IoT Platform.
The user is responsible for providing the custom implementation that usually contains the device’s network communication protocol, as well as for providing the business logic and everything related to the used hardware and the specifics of their particular use case.
However, all the communication that is directed towards the gateway through WolkConnect - BUS Handler is already provided with this package, an open source implementation written in Python 3 that uses the MQTT protocol over TCP/IP to communicate with WolkGateway.
- Python 3.7+
All requirements for this project can be installed on Debian based systems by invoking:
sudo apt-get install python3.7 python3-pip && python3 -m pip install pip && python3.7 -m pip install pipThe project can be installed using Python's package manager pip:
sudo python3.7 -m pip install wolk-gateway-moduleor installed from source by cloning the repository and running:
sudo python3.7 -m pip install -r requirements.txt
python3.7 setup.py installimport wolk_gateway_module as wolk
# Create device sensors
# Use data_type parameter where reading type & unit symbol are not important
generic_sensor = wolk.SensorTemplate(
name="Generic sensor",
reference="G", # References must be unique per device
data_type=wolk.DataType.NUMERIC,
description="Optional description"
)
temperature_sensor = wolk.SensorTemplate(
name="Temperature",
reference="T",
reading_type_name=wolk.ReadingTypeName.TEMPERATURE,
unit=wolk.ReadingTypeMeasurementUnit.CELSIUS,
description="Temperature sensor",
)
# Create a device template used to register the device
device_template = wolk.DeviceTemplate(
sensors=[generic_sensor, temperature_sensor]
)
# Create a device
device = wolk.Device(
name="Device",
key="DEVICE_KEY", # Unique device key
template=device_template
)# Implement a device status provider
def get_device_status(device_key: str) -> wolk.DeviceStatus:
"""Return current device status."""
if device_key == "DEVICE_KEY":
# Handle getting current device status here
return wolk.DeviceStatus.CONNECTED
wolk_module = wolk.Wolk(
host="localhost", # Host address of WolkGateway
port=1883, # TCP/IP port used for WolkGateway's MQTT broker
module_name="Python module", # Used for connection authentication
device_status_provider=get_device_status,
)
wolk_module.connect()wolk_module.disconnect()Devices need to be registered on the Platform before their data is considered valid. This is achieved by calling:
wolk_module.add_device(device)To stop listening for commands for a specific device use:
wolk_module.remove_device(device)This will only stop acknowledging inbound commands, to delete the device completely use WolkGateway or the web application, depending on who has control over devices.
Device status is obtained by calling provided device_status_provider function
wolk_module.publish_device_status("DEVICE_KEY")wolk_module.add_sensor_reading("DEVICE_KEY", "REFERENCE", "value")
# For reading with data size > 1, like location or acceleration use tuples
wolk_module.add_sensor_reading("DEVICE_KEY", "LOC", (24.534, -34.325))
# Add timestamps to reading occurred to preserve history, otherwise
# module will assign timestamp when adding it to storage
wolk_module.add_sensor_reading("KEY", "R", 12, int(round(time.time() * 1000)))
# Add multiple sensor reading for a device
wolk_module.add_sensor_readings("KEY", {"R1": "value", "R2": True}, timestamp)This method will put serialized messages in storage.
wolk_module.publish() # Publish all stored messages
wolk_module.publish("DEVICE_KEY") # Publish all stored messages for devicehumidity_alarm = wolk.AlarmTemplate(
name="High Humidity",
reference="HH",
description="High humidity has been detected"
)
device_template = wolk.DeviceTemplate(alarms=[humidity_alarm])
# Create device, Wolk instance, add device, connect...
# Will place alarm message into storage, use publish method to send
wolk_module.add_alarm("DEVICE_KEY", "HH", active=True, timestamp=None)In order to control device actuators, provide an actuation_handler and actuator_status_provider.
switch_actuator = wolk.ActuatorTemplate(
name="Switch",
reference="SW",
data_type=wolk.DataType.BOOLEAN,
description="Light switch",
)
slider_actuator = wolk.ActuatorTemplate(
name="Slider",
reference="SL",
data_type=wolk.DataType.NUMERIC,
description="Light dimmer",
)
device_template = wolk.DeviceTemplate(
actuators=[switch_actuator, slider_actuator]
)
device = wolk.Device("Device", "DEVICE_KEY", device_template)
def handle_actuation(
device_key: str, reference: str, value: Union[bool, int, float, str]
) -> None:
"""
Set device actuator identified by reference to value.
Must be implemented as non blocking.
Must be implemented as thread safe.
"""
if device_key == "DEVICE_KEY":
if reference == "SW":
# Handle setting the value here
switch.value = value
elif reference == "SL":
slider.value = value
def get_actuator_status(
device_key: str, reference: str
) -> Tuple[wolk.ActuatorState, Union[bool, int, float, str]]:
"""
Get current actuator status identified by device key and reference.
Reads the status of actuator from the device
and returns it as a tuple containing the actuator state and current value.
Must be implemented as non blocking.
Must be implemented as thread safe.
"""
if device_key == "DEVICE_KEY":
if reference == "SW":
# Handle getting current actuator value here
return wolk.ActuatorState.READY, switch.value
elif reference == "SL":
return wolk.ActuatorState.READY, slider.value
# Pass functions to Wolk instance
wolk_module = wolk.Wolk(
host="localhost",
port=1883,
module_name="Python module",
device_status_provider=get_device_status,
actuation_handler=handle_actuation,
actuator_status_provider=get_actuator_status,
)
wolk_module.add_device(device)
wolk_module.connect()
# This method will call the provided actuator_status_provider function
# and publish the state immediately or store message if unable to publish
wolk_module.publish_actuator_status("DEVICE_KEY", "SW")
wolk_module.publish_actuator_status("DEVICE_KEY", "SL")Similar to actuators, using device configuration options requires providing a configuration_handler and a configuration_provider to the Wolk instance.
logging_level_configuration = wolk.ConfigurationTemplate(
name="Logging level",
reference="LL",
data_type=wolk.DataType.STRING,
default_value="INFO",
description="eg. Set device logging level",
)
logging_interval_configuration = wolk.ConfigurationTemplate(
name="Logging interval",
reference="LI",
data_type=wolk.DataType.NUMERIC,
size=3,
labels=["seconds", "minutes", "hours"],
description="eg. Set logging intervals",
)
device_template = wolk.DeviceTemplate(
configurations=[logging_level_configuration, logging_level_configuration]
)
device = wolk.Device("Device", "DEVICE_KEY", device_template)
def get_configuration(
device_key: str
) -> Dict[
str,
Union[
int,
float,
bool,
str,
Tuple[int, int],
Tuple[int, int, int],
Tuple[float, float],
Tuple[float, float, float],
Tuple[str, str],
Tuple[str, str, str],
],
]:
"""
Get current configuration options.
Reads device configuration and returns it as a dictionary
with device configuration reference as key,
and device configuration value as value.
Must be implemented as non blocking.
Must be implemented as thread safe.
"""
if device_key == "DEVICE_KEY":
# Handle getting configuration values here
return {
"LL": get_log_level(),
"LI": get_log_inteval(),
}
def handle_configuration(
device_key: str,
configuration: Dict[
str,
Union[
int,
float,
bool,
str,
Tuple[int, int],
Tuple[int, int, int],
Tuple[float, float],
Tuple[float, float, float],
Tuple[str, str],
Tuple[str, str, str],
],
],
) -> None:
"""
Change device's configuration options.
Must be implemented as non blocking.
Must be implemented as thread safe.
"""
if device_key == "DEVICE_KEY":
for reference, value in configuration.items():
# Handle setting configuration values here
if reference == "LL":
set_log_level(value)
elif reference == "LI":
set_log_interval(value)
# Pass functions to Wolk instance
wolk_module = wolk.Wolk(
host="localhost",
port=1883,
module_name="Python module",
device_status_provider=get_device_status,
configuration_provider=get_configuration,
configuration_handler=handle_configuration,
)
wolk_module.add_device(device)
wolk_module.connect()
# This method will call the provided configuration_provider function
# and publish the state immediately or store message if unable to publish
wolk_module.publish_configuration("DEVICE_KEY")In order to enable firmware update for devices, provide an implementation of FirmwareHandler and pass to Wolk instance.
device_template = wolk.DeviceTemplate(supports_firmware_update=True)
device = wolk.Device("Device", "DEVICE_KEY", device_template)
class FirmwareHandlerImplementation(wolk.FirmwareHandler):
"""Handle firmware installation and abort commands, and report version.
Once an object of this class is passed to a Wolk object,
it will set callback methods `on_install_success` and
`on_install_fail` used for reporting the result of
the firmware update process. Use these callbacks in `install_firmware`
and `abort_installation` methods."""
def install_firmware(
self, device_key: str, firmware_file_path: str
) -> None:
"""
Handle the installation of the firmware file.
Call `self.on_install_success(device_key)` to report success.
Reporting success will also get new firmware version.
If installation fails, call `self.on_install_fail(device_key, status)`
where:
`status = FirmwareUpdateStatus(
FirmwareUpdateState.ERROR,
FirmwareUpdateErrorCode.INSTALLATION_FAILED
)`
or use other values from `FirmwareUpdateErrorCode` if they fit better.
"""
if device_key == "DEVICE_KEY":
print(
f"Installing firmware: '{firmware_file_path}' "
f"on device '{device_key}'"
)
# Handle the actual installation here
if install_success:
self.on_install_success(device_key)
else:
status = wolk.FirmwareUpdateStatus(
wolk.FirmwareUpdateState.ERROR,
wolk.FirmwareUpdateErrorCode.INSTALLATION_FAILED,
)
self.on_install_fail(device_key, status)
def abort_installation(self, device_key: str) -> None:
"""
Attempt to abort the firmware installation process for device.
Call `self.on_install_fail(device_key, status)` to report if
the installation process was able to be aborted with
`status = FirmwareUpdateStatus(FirmwareUpdateState.ABORTED)`
If unable to stop the installation process, no action is required.
"""
if device_key == "DEVICE_KEY":
# Manage to stop firmware installation
status = wolk.FirmwareUpdateStatus(
wolk.FirmwareUpdateState.ABORTED
)
self.on_install_fail(device_key, status)
def get_firmware_version(self, device_key: str) -> str:
"""Return device's current firmware version."""
if device_key == "DEVICE_KEY":
# Handle getting the current firmware version here
return version
wolk_module = wolk.Wolk(
host="localhost",
port=1883,
module_name="Python module",
device_status_provider=get_device_status,
firmware_handler=FirmwareHandlerImplementation(),
)
wolk_module.add_device(device)
wolk_module.connect()Enable debug logging with:
wolk.logging_config("debug", log_file=None)Data persistence mechanism used by default stored messages in-memory.
In cases when provided in-memory persistence is suboptimal, it it possible to use custom persistence by implementing OutboundMessageQueue and passing it in the following manner:
wolk_module = wolk.Wolk(
host="localhost",
port=1883,
module_name="Python module",
device_status_provider=get_device_status,
outbound_message_queue=CustomPersistence()
)