code.py

# SPDX-FileCopyrightText: 2018 Dave Astels for Adafruit Industries
#
# SPDX-License-Identifier: MIT

"""
PyPortal UV Index display

Adafruit invests time and resources providing this open source code.
Please support Adafruit and open source hardware by purchasing
products from Adafruit!

Written by Dave Astels for Adafruit Industries
Copyright (c) 2019 Adafruit Industries
Licensed under the MIT license.

All text above must be included in any redistribution.
"""

import time
import json
import board
import displayio
from adafruit_pyportal import PyPortal
from adafruit_display_shapes.rect import Rect
from adafruit_display_text.Label import Label
from adafruit_bitmap_font import bitmap_font

try:
    from secrets import secrets
except ImportError:
    print("""WiFi settings are kept in secrets.py, please add them there!
the secrets dictionary must contain 'ssid' and 'password' at a minimum""")
    raise

MAX_BAR_HEIGHT = 160
MARGIN = 10
SPACE_BETWEEN_BARS = 1

COLORS = [0x00FF00, 0x83C602, 0xa2CF02,
          0xF7DE03, 0xF6B502, 0xF78802,
          0xF65201, 0xEA2709,
          0xDA0115, 0xFC019E, 0xB548FF,
          0x988FFE, 0x7EA7FE, 0x66BFFD, 0x4BD9FF]

cwd = ("/"+__file__).rsplit('/', 1)[0]

CAPTION_FONT_FILE = cwd+'/fonts/Helvetica-Bold-16.bdf'
BAR_FONT_FILE = cwd+'/fonts/Arial-Bold-12.bdf'

#pylint:disable=line-too-long
url = 'https://enviro.epa.gov/enviro/efservice/getEnvirofactsUVHOURLY/ZIP/{0}/JSON'.format(secrets['zip'])
#pylint:enable=line-too-long

def extract_hour(date_time):
    """Extract the hour in a format to use for display:
    :param date_time: the timestamp from EPA UV readings
    """
    split_date_time = date_time.split()
    hour = split_date_time[1]
    suffix = split_date_time[2]
    if hour[0] == '0':
        hour = hour[1]
    return '\n'.join([hour, suffix])

def extract_date(date_time):
    """Extract the date in a format to use for display:
    :param date_time: the timestamp from EPA UV readings
    """
    return ' '.join(date_time.split('/')[0:2])

pyportal = PyPortal(url=url,
                    status_neopixel=board.NEOPIXEL,
                    default_bg=0xFFFFFF,
                    caption_font=CAPTION_FONT_FILE)

canvas = displayio.Group()
pyportal.splash.append(canvas)
bar_font = bitmap_font.load_font(BAR_FONT_FILE)

while True:
    json_payload = ''
    try:
        json_payload = pyportal.fetch()
        raw_data = json.loads(json_payload)
    except (ValueError, RuntimeError) as ex:
        print('Error: ', ex)
        if isinstance(ex, ValueError):
            print('JSON:', json_payload)
        print('Retrying in 10 minutes')
        time.sleep(600)
        continue
    data = []
    for d in raw_data:
        if d['UV_VALUE'] > 0:
            entry = {}
            entry['hour'] = extract_hour(d['DATE_TIME'])
            entry['value'] = int(d['UV_VALUE'])
            data.append(entry)
    the_day = raw_data[0]['DATE_TIME']
    pyportal.set_caption('UV Index for {0}'.format(extract_date(the_day)),
                         (80, 20),
                         0x000000)
    number_of_readings = len(data)
    whitespace = (number_of_readings - 1) * SPACE_BETWEEN_BARS + 2 * MARGIN
    bar_width = (320 - whitespace) // number_of_readings
    max_reading = max([d['value'] for d in data])

    while len(canvas) > 0:
        canvas.pop()

    for i, reading in enumerate(data):
        bar_height = (MAX_BAR_HEIGHT * reading['value']) // max_reading
        x = int(MARGIN + i * (bar_width + SPACE_BETWEEN_BARS))
        canvas.append(Rect(x, 200 - bar_height,
                           bar_width, bar_height,
                           fill=COLORS[reading['value']]))
        canvas.append(Label(bar_font,
                            x=x+3, y=220,
                            text=reading['hour'],
                            color=0x000000,
                            line_spacing=0.6))
        canvas.append(Label(bar_font,
                            x=x+(bar_width//2)-4, y=208-bar_height,
                            text=str(reading['value']),
                            color=0x000000))

    time.sleep(3600)                  #refresh hourly