main.py

"""Put a Sonoff S20 onto CatBus."""

# pylint: disable=bare-except
# pylint: disable=import-error
# pylint: disable=invalid-name
# pylint: disable=too-few-public-methods
# pylint: disable=unused-argument

import time

import machine
import umqtt.simple as umqtt

import catbus_config


class Button(machine.Pin):
    """An input button that calls a callback when pressed."""

    def __init__(self, pin=0):
        super().__init__(pin, machine.Pin.IN)

        # Timer -1 is a "virtual" RTOS timer, rather than a hardware one.
        self._timer = machine.Timer(-1)

    def set_callback(self, callback):

        # The timer callback has a parameter, so this consumes that.
        def _callback(timer):
            callback()

        def debounce_button(pin):
            self._timer.init(mode=machine.Timer.ONE_SHOT,
                             period=200, callback=_callback)

        self.irq(trigger=machine.Pin.IRQ_RISING, handler=debounce_button)


class Relay(machine.Pin):
    """An output relay."""

    def __init__(self, pin=12):
        super().__init__(pin, machine.Pin.OUT)

    def toggle(self):
        if self.value() == 0:
            self.on()
        else:
            self.off()

    def value_catbus(self):
        return b'on' if self.value() else b'off'


class LED(machine.Pin):
    """The non-relay LED on the front of the device.

    The LED on the Sonoff is LOW for on and HIGH for off."""

    def __init__(self, pin=13):
        super().__init__(pin, machine.Pin.OUT)

    def on(self):
        super().off()

    def off(self):
        super().on()


button = Button()
relay = Relay()
status_led = LED()


def main():
    # Setup begins.
    status_led.on()

    config = catbus_config.Config()

    if not config.device_name:
        # We haven't been set up and can't do anything.
        return

    topic = config.mqtt_topic.encode('utf-8')

    def on_message(topic, data):
        if data == b'on':
            relay.on()
        elif data == b'off':
            relay.off()
        else:
            pass

    mqtt = umqtt.MQTTClient(config.device_name, config.mqtt_broker)
    mqtt.set_callback(on_message)
    mqtt.connect()
    mqtt.subscribe(topic, qos=1)

    def on_button_pressed():
        relay.toggle()
        mqtt.publish(topic, relay.value_catbus(),
                     retain=True, qos=1)

    button.set_callback(on_button_pressed)

    # Setup finished.
    status_led.off()

    while True:
        try:
            mqtt.wait_msg()
        except:
            status_led.on()
            try:
                mqtt.connect()
                mqtt.subscribe(topic, qos=1)
                status_led.off()
            except:
                time.sleep(1)


main()