A python script that polls the CheerLights API and sets the LEDs of a Blinkt! hat.

cheerlights.py

# curl https://get.pimoroni.com/blinkt | bash

import blinkt
import requests

from collections import deque
from requests.adapters import HTTPAdapter
from requests.exceptions import ConnectionError
from sys import exit
from time import sleep

DIM = 0.1
BRIGHT = 1.0

adapter = HTTPAdapter(max_retries=10)
session = requests.Session()
session.mount("http://api.thingspeak.com", adapter)


def hex_to_rgb(hexcolor):
    # strip the hash mark and convert hex value to an RGB array
    hexcolor = hexcolor.lstrip("#")
    return bytearray.fromhex(hexcolor)


def load_color_feed(colors):
    # load full API with color history
    r = session.get("http://api.thingspeak.com/channels/1417/feed.json", timeout=30)
    feeds = r.json()["feeds"]
    previous = None

    # append new color to array if different from previous
    for entry in feeds:
        color = entry.get("field2")
        if color != previous:
            previous = color
            colors.append(color)

    # reverse the order of the list and truncate it to show the newest 8 colors
    colors.reverse()
    for i in range(0, len(colors) - blinkt.NUM_PIXELS):
        colors.pop()


def load_newest_color(colors):
    # load last API with the newest color
    r = session.get("http://api.thingspeak.com/channels/1417/field/2/last.json", timeout=30)
    color = r.json()["field2"]
    previous = colors[0]

    # prepend new color to array if different from previous
    if color != previous:
        print("new color: ", color)
        previous = color
        # shift the array to the right
        colors.rotate(1)
        # pop the color that wrapped around from the end
        colors.popleft()
        # put the new color in it's place
        colors.appendleft(color)
        # blink the LEDs with the new color
        blink_color(color)


def set_pixel(pixel, color, brightness = DIM):
    r, g, b = hex_to_rgb(color)
    # set the pixel to the RGB value
    blinkt.set_pixel(pixel, r, g, b, brightness)
    blinkt.show()


def set_all_pixels(color = "#000000", brightness = DIM):
    r, g, b = hex_to_rgb(color)
    blinkt.set_all(r, g, b, brightness)
    blinkt.show()


def set_colors(colors):
    for i in range(blinkt.NUM_PIXELS):
        c = colors[i]
        set_pixel(i, c)


def blink_color(color):
    set_all_pixels()
    for i in range(3):
        set_all_pixels(color, BRIGHT)
        sleep(1)
        set_all_pixels()
        sleep(1)


try:
    blinkt.set_brightness(DIM)
    blinkt.set_clear_on_exit(True)

    # store the colors in a "list-like container with fast appends and pops on either end"
    colors = deque()

    load_color_feed(colors)
    set_colors(colors)
    print("initial colors: ", colors)
    sleep(10)

    while True:
        load_newest_color(colors)
        set_colors(colors)
        sleep(10)

except ConnectionError as e:
    print(e)

except KeyboardInterrupt:
    exit