gpiotrigger.py

import logging
import threading
import time

import RPi.GPIO as GPIO

from spreads.plugin import HookPlugin, TriggerHooksMixin
from spreads.util import DeviceException


class GpioTrigger(HookPlugin, TriggerHooksMixin):
    __name__ = 'gpiotrigger'

    _loop_thread = None
    _exit_event = None

    def configuration_template(cls):
        return { 'pin_number': PluginOption(
                    value=17, docstring="GPIO Pin to watch")}

    def __init__(self, config):
        self._logger = logging.getLogger('spreadsplug.gpiotrigger')
        self._logger.debug("Initializing GpioTrigger plugin")
        self._trigger_pin = config['pin_number'].get(int)

    def start_trigger_loop(self, capture_callback):
        GPIO.setmode(GPIO.BCM)
        GPIO.setup(buttonPin,GPIO.IN)

        self._exit_event = threading.Event()
        self._loop_thread = threading.Thread(target=self._trigger_loop,
                                             args=(capture_callback, ))
        self._logger.debug("Starting trigger loop")
        self._loop_thread.start()

    def stop_trigger_loop(self):
        if self._exit_event is None:
            # Return if no loop thread is running
            return
        self._logger.debug("Stopping trigger loop")
        self._exit_event.set()
        self._loop_thread.join()

    def _trigger_loop(self, capture_func):
        # Polls all attached HID devices for a press->release event and
        # trigger a capture.
        while not self._exit_event.is_set():
            if (GPIO.input(self._trigger_pin)):
                capture_func()