core/homeassistant/components/arduino.py

"""
Support for Arduino boards running with the Firmata firmware.

For more details about this component, please refer to the documentation at
https://home-assistant.io/components/arduino/
"""
import logging

from homeassistant.const import (
    EVENT_HOMEASSISTANT_START, EVENT_HOMEASSISTANT_STOP)
from homeassistant.helpers import validate_config

DOMAIN = "arduino"
REQUIREMENTS = ['PyMata==2.07a']
BOARD = None
_LOGGER = logging.getLogger(__name__)


def setup(hass, config):
    """Setup the Arduino component."""
    if not validate_config(config,
                           {DOMAIN: ['port']},
                           _LOGGER):
        return False

    import serial
    global BOARD
    try:
        BOARD = ArduinoBoard(config[DOMAIN]['port'])
    except (serial.serialutil.SerialException, FileNotFoundError):
        _LOGGER.exception("Your port is not accessible.")
        return False

    if BOARD.get_firmata()[1] <= 2:
        _LOGGER.error("The StandardFirmata sketch should be 2.2 or newer.")
        return False

    def stop_arduino(event):
        """Stop the Arduino service."""
        BOARD.disconnect()

    def start_arduino(event):
        """Start the Arduino service."""
        hass.bus.listen_once(EVENT_HOMEASSISTANT_STOP, stop_arduino)

    hass.bus.listen_once(EVENT_HOMEASSISTANT_START, start_arduino)

    return True


class ArduinoBoard(object):
    """Represents an Arduino board."""
    def __init__(self, port):
        from PyMata.pymata import PyMata
        self._port = port
        self._board = PyMata(self._port, verbose=False)

    def set_mode(self, pin, direction, mode):
        """Set the mode and the direction of a given pin."""
        if mode == 'analog' and direction == 'in':
            self._board.set_pin_mode(pin,
                                     self._board.INPUT,
                                     self._board.ANALOG)
        elif mode == 'analog' and direction == 'out':
            self._board.set_pin_mode(pin,
                                     self._board.OUTPUT,
                                     self._board.ANALOG)
        elif mode == 'digital' and direction == 'in':
            self._board.set_pin_mode(pin,
                                     self._board.OUTPUT,
                                     self._board.DIGITAL)
        elif mode == 'digital' and direction == 'out':
            self._board.set_pin_mode(pin,
                                     self._board.OUTPUT,
                                     self._board.DIGITAL)
        elif mode == 'pwm':
            self._board.set_pin_mode(pin,
                                     self._board.OUTPUT,
                                     self._board.PWM)

    def get_analog_inputs(self):
        """Get the values from the pins."""
        self._board.capability_query()
        return self._board.get_analog_response_table()

    def set_digital_out_high(self, pin):
        """Set a given digital pin to high."""
        self._board.digital_write(pin, 1)

    def set_digital_out_low(self, pin):
        """Set a given digital pin to low."""
        self._board.digital_write(pin, 0)

    def get_digital_in(self, pin):
        """Get the value from a given digital pin."""
        self._board.digital_read(pin)

    def get_analog_in(self, pin):
        """Get the value from a given analog pin."""
        self._board.analog_read(pin)

    def get_firmata(self):
        """Return the version of the Firmata firmware."""
        return self._board.get_firmata_version()

    def disconnect(self):
        """Disconnects the board and closes the serial connection."""
        self._board.reset()
        self._board.close()