Source code for

import logging
from datetime import datetime, timedelta
import numpy as np
import pytz

from .station import WeatherStation

log = logging.getLogger(__name__)

[docs]class Current(WeatherStation): """The Current weather station requests all values from all other weather stations and just averages the lates values for all sensor types. This station gets configured by the *initweather* script and is running in an interval every 10 seconds. All sensors of this station that are vital for operation should have :ref:`Valid <>` evaluators attached to them."""
[docs] def create_sensors(self): """Entry point for creating sensors for this station. No sensors created here, that all happens on-the-fly in update().""" pass
[docs] def update(self): """Entry point for updating sensor values for this station. This method loops all sensor types and fetches all related sensors from all stations and calculates averages of the latest values, which it stores in sensors of the same type. Values from other stations are only used if they are not older than 10 minutes. """ from import SensorType, Sensor, Value'Updating current...') # get now now = datetime.utcnow().astimezone(pytz.UTC) # loop all sensor types for sensor_type in SensorType.objects.all(): values = [] # loop all sensors of that type for sensor in Sensor.objects.filter(type=sensor_type, average=True, station__active=True): # skip average and current if sensor.station.code in ['average', 'current']: continue # get latest value of that sensor value = Value.objects.filter(sensor=sensor).order_by('-time').first() # valid? if value is not None and value.value is not None: # and not too old? if value.time > now - timedelta(minutes=10): # add it values.append(value.value) # calculate average avg = np.mean(values) if values else None # and store it sensor = self._add_sensor(sensor_type.code) Value.objects.get_or_create(sensor=sensor, time=now, value=avg)
__all__ = ['Current']