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Asynchronous library to receive UDP Packets from Weatherflow Weatherstations

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pyweatherflowudp

An event-based asynchronous library to read UDP packets from Weatherflow weather systems on a local network without any reliance on the cloud.

The atomic data provided by WeatherFlow sensors is all natively metric. To help facilitate transformations to other units or to perform calculations and comparisons, this module utilizes Pint's Quantity class as the type of most properties which have a unit of measurement. See the Quantity section below for more details.

This module utilizes PsychroLib to help with additional weather calculations that are derived from the various data points provided by the actual WeatherFlow sensors. While WeatherFlow has these additional data points available via the app and rest API, they are unavailable via the low-level UDP packet data. And while a list of derived metrics and the associated equations has been posted, they can be quite complex to implement, such as calculating wet bulb temperature. As such, PsychroLib is an invaluable resource since the work has already been done and it eliminates the need to write all the equations in this module (and potentially get them wrong). You may notice that some of these values aren't an exact match with what is shown in the WeatherFlow app because there are different formulas (some simpler, some more complex) to calculate derived weather metrics. This is because WeatherFlow and PsychroLib may have chosen one of the sometimes many different formulas to get the result desired. They should still be relatively close, however.

DOI DOI

Supported Devices

  • Tempest
  • Air (untested)
  • Sky (untested)

Usage

The primary way of interacting with this module, and the devices that are found with it, is via event subscriptions.

The classes and events which they currently support are outlined below, but you can also see an example tying this altogether in demo.py.

Client

WeatherFlowListener

  • EVENT_DEVICE_DISCOVERED - emitted when a new device (Hub, Air, Sky or Tempest) is disovered for the first time

The classes and events in this section can be imported from pyweatherflowudp.client.

Devices

HubDevice

  • EVENT_LOAD_COMPLETE - emitted once when the hub has finished parsing a status update for the first time
  • EVENT_STATUS_UPDATE - emitted each time a status update has been parsed by the hub, including immediately following an EVENT_LOAD_COMPLETE

WeatherFlowSensorDevice (base class for AirDevice, SkyDevice and TempestDevice)

  • EVENT_LOAD_COMPLETE - emitted once when the sensor has finished parsing one status update and one observation for the first time
  • EVENT_OBSERVATION - emitted each time an observation has been parsed by the sensor
  • EVENT_STATUS_UPDATE - emitted each time a status update has been parsed by the sensor

AirSensorType (AirDevice / TempestDevice)

  • EVENT_STRIKE - emitted when a lightning strike has been detected

SkySensorType (SkyDevice / TempestDevice)

  • EVENT_RAIN_START - emitted when rain has been detected
  • EVENT_RAPID_WIND - emitted every 3 seconds (or less frequently depending on battery voltage) to inform about current wind condtions

The classes and events in this section can be imported from pyweatherflowudp.device.

Properties and Methods

WeatherFlowListener

property type description
devices list The known devices.
hubs list The known hubs.
is_listening bool True if the listener is currently monitoring UDP packets on the network, else False.
sensors list The known sensors.

WeatherFlowDevice

Base for hubs and sensors.

property type description
firmware_revision str The current firmware revision of the device.
load_complete bool True if the device has parsed all initial updates, else False.
model str The model of the device ("Hub", "Air", "Sky", "Tempest").
rssi Quantity The signal strength of the device in decibels.
serial_number str The serial number of the device.
timestamp datetime The UTC timestamp from the last status update.
up_since datetime The UTC timestamp the device started up and has since been running.
uptime int The number of seconds the device has been up and running.

HubDevice

property type description
reset_flags list The current reset flags of the hub.

WeatherFlowSensorDevice

Base for sensors.

property type description
battery Quantity The current battery voltage.
hub_rssi Quantity The signal strength of the hub in decibels.
hub_sn str The serial number of the hub the sensor belongs to.
last_report datetime The UTC timestamp from the last observation.
sensor_status list The list of issues the sensor is currently reporting.
report_interval Quantity The report interval in minutes.
reset_flags list The current reset flags of the hub.

AirSensorType

Base for "air" sensor measurements (Air/Tempest).

property type description
air_temperature Quantity The current air temperature in degrees Celsius.
last_lightning_strike_event LightningStrikeEvent The last lightning strike event.
lightning_strike_average_distance Quantity The average distance for lightning strikes in kilometers.
lightning_strike_count int The number of lightning strikes.
relative_humidity Quantity The relative humidity percentage.
station_pressure Quantity The observed station pressure in millibars.
air_density* Quantity The calculated air density in kilograms per cubic meter.
delta_t* Quantity The calculated Delta T in delta degrees Celsius.
dew_point_temperature* Quantity The calculated dew point temperature in degrees Celsius.
heat_index* Quantity The calculated heat index in degrees Celsius.
vapor_pressure* Quantity The calculated vapor pressure in millibars.
wet_bulb_temperature* Quantity The calculated wet bulb temperature in degrees Celsius.

* Indicates derived properties

method input (type) return description
calculate_cloud_base altitude (Quantity) Quantity Calculate the estimated altitude above mean sea level (AMSL) to the cloud base.
calculate_freezing_level altitude (Quantity) Quantity Calculate the estimated altitude above mean sea level (AMSL) where the temperature is at the freezing point (0°C/32°F).
calculate_sea_level_pressure altitude (Quantity) Quantity Calculate the mean sea level pressure.

SkySensorType

Base for "sky" sensor measurements (Sky/Tempest).

property type description
illuminance Quantity The current illuminance in Lux.
last_rain_start_event RainStartEvent The last rain start event.
last_wind_event WindEvent The last wind event.
precipitation_type PrecipitationType The current precipitation type: (NONE, RAIN, HAIL or RAIN_HAIL).
rain_accumulation_previous_minute Quantity The rain accumulation from the previous minute in millimeters.
rain_rate* Quantity The rain rate in millimeters per hour (based on the previous minute accumulation).
solar_radiation Quantity The solar radiation in Watts per cubic meter.
uv int The current UV index.
wind_average Quantity The wind speed average over the report interval in meters per second.
wind_direction Quantity The wind direction over the report interval in degrees.
wind_direction_cardinal string The wind direction cardinal (16-wind compass rose).
wind_gust Quantity The wind gust (maximum 3 second sample) in meters per second.
wind_lull Quantity The wind lull (minimum 3 second sample) in meters per second.
wind_sample_interval Quantity The wind sample interval in seconds.
wind_speed Quantity The wind speed in meters per second.

* Indicates derived properties

TempestDevice

property type description
feels_like_temperature* Quantity The calculated "feels like" temperature in degrees Celsius.
wind_chill_temperature* Quantity The calculated wind chill temperature in degrees Celsius.

* Indicates derived properties

Quantity

The pint.Quantity class has been utilized for device properties which are associated with a unit of measurement. This allows a conversion from the native metric unit to another of the user's choice such as degrees Celsius to degrees Fahrenheit, which produces another pint.Quantity:

device.air_temperature.to("degF")

To retrieve only the numeric value of a property, you can just append a .magnitude (or .m short form) like:

device.air_temperature.m

You can also retrieve only the units portion of a property with .units (or .u short form) like:

device.air_temperature.u

Check out the Pint docs for more tips.

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