daily_xkcd.py

import gc
import uos
import machine
import jpegdec
import sdcard
from urllib import urequest

"""
xkcd daily

You *must* insert an SD card into Inky Frame!
We need somewhere to save the jpg for display.

Fetches a pre-processed XKCD daily image from:
https://pimoroni.github.io/feed2image/xkcd-daily.jpg

See https://xkcd.com/ for more webcomics!
"""

graphics = None
WIDTH = None
HEIGHT = None

UPDATE_INTERVAL = 240

gc.collect()  # We're really gonna need that RAM!

FILENAME = "/sd/xkcd-daily.jpg"
ENDPOINT = "https://pimoroni.github.io/feed2image/xkcd-daily.jpg"

sd_spi = machine.SPI(0, sck=machine.Pin(18, machine.Pin.OUT), mosi=machine.Pin(19, machine.Pin.OUT), miso=machine.Pin(16, machine.Pin.OUT))
sd = sdcard.SDCard(sd_spi, machine.Pin(22))
uos.mount(sd, "/sd")
gc.collect()  # Claw back some RAM!


def update():
    url = ENDPOINT

    if (WIDTH, HEIGHT) != (600, 448):
        url = url.replace("xkcd-", f"xkcd-{WIDTH}x{HEIGHT}-")

    socket = urequest.urlopen(url)

    # Stream the image data from the socket onto disk in 1024 byte chunks
    # the 600x448-ish jpeg will be roughly ~24k, we really don't have the RAM!
    data = bytearray(1024)
    with open(FILENAME, "wb") as f:
        while True:
            if socket.readinto(data) == 0:
                break
            f.write(data)
    socket.close()
    gc.collect()  # We really are tight on RAM!


def draw():

    gc.collect()  # For good measure...

    jpeg = jpegdec.JPEG(graphics)

    graphics.set_pen(1)
    graphics.clear()

    jpeg.open_file(FILENAME)
    jpeg.decode()

    graphics.update()