gardencontrol/heat/_Heat.py

import datetime
import logging
import threading
import time

import RPi.GPIO as GPIO

class Heat(threading.Thread):
    def __init__(self, pin):
        threading.Thread.__init__(self)
        self.__pin = pin
        self.__state = False
        self.__lock = threading.Lock()

        GPIO.setwarnings(False)
        GPIO.setmode(GPIO.BCM)
        GPIO.setup(pin, GPIO.OUT)

        if not GPIO.input(pin):
            self.__state = True
        self.__run_condition = True
        self.__next_update = datetime.datetime.now()

    def on(self):
        """Switch the heat on"""
        with self.__lock:
            self.__state = True
            GPIO.output(self.__pin, 0)

    def off(self):
        """Switch the heat off"""
        with self.__lock:
            self.__state = False
            GPIO.output(self.__pin, 1)

    def run(self):
        self.__next_update = datetime.datetime.now()
        while self.__run_condition:
            now = datetime.datetime.now()
            if now >= self.__next_update:
                if self.__state:
                    # Do a power cycle to prevent auto-poweroff
                    GPIO.output(self.__pin, 1)
                    time.sleep(5)
                    GPIO.output(self.__pin, 0)
                self.__next_update = now + datetime.timedelta(minutes=5)
            time.sleep(1)
        self.off()

    def stop(self):
        """Stop the controlling thead"""
        self.__run_condition = False
        self.join()

    def state(self):
        """Return the state of the heat"""
        return self.__state