craftbeerpi3/modules/base_plugins/fermenter_hysteresis/__init__.py

from modules import cbpi
from modules.core.controller import KettleController, FermenterController
from modules.core.props import Property


@cbpi.fermentation_controller
class Hysteresis(FermenterController):

    heater_offset_min = Property.Number("Heater Offset ON", True, 0, description="Offset as decimal number when the heater is switched on. Should be greater then 'Heater Offset OFF'. For example a value of 2 switches on the heater if the current temperature is 2 degrees below the target temperature")
    heater_offset_max = Property.Number("Heater Offset OFF", True, 0, description="Offset as decimal number when the heater is switched off. Should be smaller then 'Heater Offset ON'. For example a value of 1 switches off the heater if the current temperature is 1 degree below the target temperature")
    cooler_offset_min = Property.Number("Cooler Offset ON", True, 0, description="Offset as decimal number when the cooler is switched on. Should be greater then 'Cooler Offset OFF'. For example a value of 2 switches on the cooler if the current temperature is 2 degrees above the target temperature")
    cooler_offset_max = Property.Number("Cooler Offset OFF", True, 0, description="Offset as decimal number when the cooler is switched off. Should be less then 'Cooler Offset ON'. For example a value of 1 switches off the cooler if the current temperature is 1 degree above the target temperature")

    def stop(self):
        super(FermenterController, self).stop()

        self.heater_off()
        self.cooler_off()

    def run(self):
        while self.is_running():

            try:

                target_temp = self.get_target_temp()
                temp = self.get_temp()

                if target_temp is not None and temp is not None:

                    if temp + float(self.heater_offset_min) <= target_temp:
                        self.heater_on(100)

                    if temp + float(self.heater_offset_max) >= target_temp:
                        self.heater_off()

                    if temp >= target_temp + float(self.cooler_offset_min):
                        self.cooler_on(100)

                    if temp <= target_temp + float(self.cooler_offset_max):
                        self.cooler_off()

            except Exception as e:
                cbpi.notify("Fermentation Loop Stuck", "Please check the CraftBeerPi system.\r\nError %s" % (str(e)), type="danger", timeout=None)
                self.sleep(60)

            self.sleep(1)