core/homeassistant/components/arduino/sensor.py

"""Support for getting information from Arduino pins."""
import logging

import voluptuous as vol

from homeassistant.components.sensor import PLATFORM_SCHEMA
from homeassistant.components import arduino
from homeassistant.const import CONF_NAME
from homeassistant.helpers.entity import Entity
import homeassistant.helpers.config_validation as cv

_LOGGER = logging.getLogger(__name__)

CONF_PINS = 'pins'
CONF_TYPE = 'analog'

PIN_SCHEMA = vol.Schema({
    vol.Required(CONF_NAME): cv.string,
})

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
    vol.Required(CONF_PINS):
        vol.Schema({cv.positive_int: PIN_SCHEMA}),
})


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Set up the Arduino platform."""
    if arduino.BOARD is None:
        _LOGGER.error("A connection has not been made to the Arduino board")
        return False

    pins = config.get(CONF_PINS)

    sensors = []
    for pinnum, pin in pins.items():
        sensors.append(ArduinoSensor(pin.get(CONF_NAME), pinnum, CONF_TYPE))
    add_entities(sensors)


class ArduinoSensor(Entity):
    """Representation of an Arduino Sensor."""

    def __init__(self, name, pin, pin_type):
        """Initialize the sensor."""
        self._pin = pin
        self._name = name
        self.pin_type = pin_type
        self.direction = 'in'
        self._value = None

        arduino.BOARD.set_mode(self._pin, self.direction, self.pin_type)

    @property
    def state(self):
        """Return the state of the sensor."""
        return self._value

    @property
    def name(self):
        """Get the name of the sensor."""
        return self._name

    def update(self):
        """Get the latest value from the pin."""
        self._value = arduino.BOARD.get_analog_inputs()[self._pin][1]