Hello,
I recently bought the Pimoroni Unicorn LED display for the Raspberry Pico and was rather disappointed to find only c code and python support.
I have created a library to support the display, based on the Pimoroni example:
This is not available from the Arduino IDE library manager yet but I will suggest it is included. The library uses the Adafruit_GFX support library which is well documented. I have included one example to get started but will add more in future.
You will need to use the Earle Philhower RP2040 board support package as the PIO is used to drive the display. That is available via the Arduino board manager.