platypush/platypush/plugins/gpio/__init__.py

"""
.. moduleauthor:: Fabio Manganiello <blacklight86@gmail.com>
"""

import threading
import time

from platypush.plugins import Plugin, action


class GpioPlugin(Plugin):
    """
    Plugin to handle raw read/write operation on the Raspberry Pi GPIO pins.

    Requires:
        * **RPi.GPIO** (`pip install RPi.GPIO`)
    """

    def __init__(self, pins=None, *args, **kwargs):
        """
        :param pins: Configuration for the GPIO PINs as a name -> pin_number map.
        :type pins: dict

        Example::

            {
                "LED_1": 14,
                "LED_2": 15,
                "MOTOR": 16,
                "SENSOR": 17
            }
        """

        super().__init__(*args, **kwargs)
        self.pins_by_name = pins if pins else {}
        self.pins_by_number = { number:name
                             for (name, number) in self.pins_by_name.items() }

    def _get_pin_number(self, pin):
        try:
            pin = int(str(pin))
        except ValueError:
            pin = self.pins_by_name.get(pin)
            if not pin:
                raise RuntimeError('Unknown PIN name: "{}"'.format(pin))

        return pin


    @action
    def write(self, pin, val):
        """
        Write a byte value to a pin.

        :param pin: PIN number or configured name
        :type pin: int or str

        :param val: Value to write
        :type val: int

        :returns: dict

        Response::

            output = {
                "pin": <pin>,
                "val": <val>,
                "method": "write"
            }
        """

        import RPi.GPIO as gpio

        pin = self._get_pin_number(pin)
        gpio.setmode(gpio.BCM)
        gpio.setup(pin, gpio.OUT)
        gpio.output(pin, val)

        return {
            'pin': pin,
            'val': val,
            'method': 'write',
        }

    @action
    def read(self, pin):
        """
        Reads a value from a PIN.

        :param pin: PIN number or configured name.
        :type pin: int or str
        :returns: dict

        Response::

            output = {
                "pin": <pin>,
                "val": <val>,
                "method": "read"
            }
        """

        import RPi.GPIO as gpio

        pin = self._get_pin_number(pin)
        gpio.setmode(gpio.BCM)
        gpio.setup(pin, gpio.IN)
        val = gpio.input(pin)

        return {
            'pin': pin,
            'val': val,
            'method': 'read',
        }

    @action
    def read_all(self):
        """
        Reads the values from all the configured PINs and returns them as a list. It will raise a RuntimeError if no PIN mappings were configured.
        :returns: list
        """

        import RPi.GPIO as gpio

        if not self.pins_by_number:
            raise RuntimeError("No PIN mappings were provided/configured")

        values = []
        for (pin, name) in self.pins_by_number.items():
            gpio.setmode(gpio.BCM)
            gpio.setup(pin, gpio.IN)
            val = gpio.input(pin)

            values.append({
                'pin': pin,
                'name': name,
                'val': val,
            })

        return values


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