This library allows you to control the Unicorn Hat HD with a CircuitPython board.
Pixel 0 is in the top right corner below the Unicorn Hat HD silkscreen. Pixel 255 is in the bottom right corner.
Tested on an Particle Xenon (NRF52840) running CircuitPython 4.0.1, but in theory it should work on other CircuitPython boards.
This is based on the following Arduino Library: https://github.com/Arudinne/Unicorn-Hat-HD-Arduino which itself is based on this Gist: https://gist.github.com/emoryy/24899c8dee7112d62e4adfbdaaa4826a and the Adafruit NeoPixel Library for the Arduino platform: https://github.com/adafruit/Adafruit_NeoPixel.