class platypush.backend.sensor.SensorBackend(plugin=None, plugin_args=None, thresholds=None, tolerance=1e-07, poll_seconds=None, enabled_sensors=None, **kwargs)[source]

Abstract backend for polling sensors.


__init__(plugin=None, plugin_args=None, thresholds=None, tolerance=1e-07, poll_seconds=None, enabled_sensors=None, **kwargs)[source]
  • plugin (str) – If set, then this plugin instance, referenced by plugin id, will be polled through get_plugin(). Example: 'gpio.sensor.bme280' or 'gpio.sensor.envirophat'.
  • plugin_args (dict) – If plugin is set and its get_measurement() method accepts optional arguments, then you can pass those arguments through plugin_args.
  • thresholds – Thresholds can be either a scalar value or a dictionary (e.g. {"temperature": 20.0}). Sensor threshold events will be fired when measurements get above or below these values. Set it as a scalar if your get_measurement() code returns a scalar, as a dictionary if it returns a dictionary of values. For instance, if your sensor code returns both humidity and temperature in a format like {'humidity':60.0, 'temperature': 25.0}, you’ll want to set up a threshold on temperature with a syntax like {'temperature':20.0} to trigger events when the temperature goes above/below 20 degrees.
  • tolerance (dict or float) –

    If set, then the sensor change events will be triggered only if the difference between the new value and the previous value is higher than the specified tolerance. Example:

        "temperature": 0.01,  # Tolerance on the 2nd decimal digit
        "humidity": 0.1       # Tolerance on the 1st decimal digit
  • poll_seconds (float) – If set, the thread will wait for the specified number of seconds between a read and the next one.
  • enabled_sensors (dict (in the form name -> [True/False]), set or list) – If get_measurement() returns data in dict form, then enabled_sensors selects which keys should be taken into account when monitoring for new events (e.g. “temperature” or “humidity”).

Wrapper around plugin.get_measurement() that can filter events on specified enabled sensors data or on specified tolerance values. It can be overridden by derived classes.


Callback invoked when the process stops


Starts the backend thread. To be implemented in the derived classes if the loop method isn’t defined.