python/coral-enviro/coral/enviro/enviro_demo.py

# Copyright 2019 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from coral.enviro.board import EnviroBoard
from coral.cloudiot.core import CloudIot
from luma.core.render import canvas
from PIL import ImageDraw
from time import sleep

import argparse
import itertools


def update_display(display, msg):
    with canvas(display) as draw:
        draw.text((0, 0), msg, fill='white')


def _none_to_nan(val):
    return float('nan') if val is None else val


def main():
    # Pull arguments from command line.
    parser = argparse.ArgumentParser(description='Enviro Kit Demo')
    parser.add_argument('--display_duration',
                        help='Measurement display duration (seconds)', type=int,
                        default=5)
    parser.add_argument('--upload_delay', help='Cloud upload delay (seconds)',
                        type=int, default=300)
    parser.add_argument(
        '--cloud_config', help='Cloud IoT config file', default='my_config.ini')
    args = parser.parse_args()

    # Create instances of EnviroKit and Cloud IoT.
    enviro = EnviroBoard()
    with CloudIot(args.cloud_config) as cloud:
        # Indefinitely update display and upload to cloud.
        sensors = {}
        read_period = int(args.upload_delay / (2 * args.display_duration))
        for read_count in itertools.count():
            # First display temperature and RH.
            sensors['temperature'] = enviro.temperature
            sensors['humidity'] = enviro.humidity
            msg = 'Temp: %.2f C\n' % _none_to_nan(sensors['temperature'])
            msg += 'RH: %.2f %%' % _none_to_nan(sensors['humidity'])
            update_display(enviro.display, msg)
            sleep(args.display_duration)
            # After 5 seconds, switch to light and pressure.
            sensors['ambient_light'] = enviro.ambient_light
            sensors['pressure'] = enviro.pressure
            msg = 'Light: %.2f lux\n' % _none_to_nan(sensors['ambient_light'])
            msg += 'Pressure: %.2f kPa' % _none_to_nan(sensors['pressure'])
            update_display(enviro.display, msg)
            sleep(args.display_duration)
            # If time has elapsed, attempt cloud upload.
            if read_count % read_period == 0 and cloud.enabled():
                cloud.publish_message(sensors)


if __name__ == '__main__':
    main()