GPIO Pins

[meatalhead]

Does anyone have any examples of using a webthing to turn raspi GPIO pins on and off?

[mrstegeman]

Here's an (untested) example with an LED, using the gpiozero module:

from gpiozero import LED
from webthing import Property, SingleThing, Thing, Value, WebThingServer
import logging

class LedThing(Thing):

    def __init__(self):
        Thing.__init__(
            self,
            'urn:dev:ops:led',
            ['Light'],
            'A web connected GPIO LED'
        )

        self._led = LED(17)

        self.add_property(
            Property(
                self,
                'on',
                Value(self.get_led(), self.set_led),
                metadata={
                    '@type': 'OnOffProperty',
                    'title': 'On/Off',
                    'type': 'boolean',
                    'description': 'Whether the LED is turned on',
                }
            )
        )

    def get_led(self):
        return self._led.is_lit

    def set_led(self, value):
        if value:
            self._led.on()
        else:
            self._led.off()

def run_server():
    thing = LedThing()

    # If adding more than one thing, use MultipleThings() with a name.
    # In the single thing case, the thing's name will be broadcast.
    server = WebThingServer(SingleThing(thing), port=8888)
    try:
        logging.info('starting the server')
        server.start()
    except KeyboardInterrupt:
        logging.info('stopping the server')
        server.stop()
        logging.info('done')

if __name__ == '__main__':
    logging.basicConfig(
        level=10,
        format="%(asctime)s %(filename)s:%(lineno)s %(levelname)s %(message)s"
    )
    run_server()