This is the firmware for my Digital Iris
It runs on an RP2040 running Micropython 1.27, with an 84x48 pixel PCD8544 LCD and 3 buttons.
There is a collection of effects in the apertures/ directory. Button 1 cycles through the different effects; buttons 2 and 3 are effect-specific modifiers.
You can run it, simulated, on a desktop with python3 synthetic.py - keys 1 2 and 3 are mapped to the button inputs.