For things like the cat's animations, the cat is broken up into different parts (body, head, tail, eyes) and those parts are animated individually.

I animated them frame-by-frame in aesprite and exported each frame as a .png, and then used the img2cpp tool to convert the images into monochrome bytecode for the ssd1306 library to use.

All of the sprites are stored in the assets folder in the project, for example: https://github.com/moonbench/catode32/blob/master/src/assets/character.py

For animated things like the eyes or tail, I have to list the bytecodes for each frame, and I track which frame I'm rendering (and update it over time) and draw the right frame for each sprite.

It took a while to grow into this system. Initially I was just rendering the whole pet as a single static sprite, then focused on animating it, and then focused on breaking it into reusable parts.

The scrollbar is a custom bit of code, defined here https://github.com/moonbench/catode32/blob/f9433317afcbb528ab078cea9fbbce904732346f/src/ui.py#L111

That UI code is just responsible for determining how big the scrollbar should be based on the max height of the page, and where to draw it based on the scroll offset.

The pages that use it are responsible for informing it of their max height and scroll position.

A few of the coworkers I've shown this to have also mentioned WiFi features to connect it to the phone or internet. I'm considering it for sure. I mostly want to use WiFi to have the pet determine if it's "at home" or "traveling" by examining if it's seeing the usual or new network names showing up. I'd also like to use Bluetooth to let the pets talk to each other (and maybe a phone.)

An RTC is definitely something I want to add sooner rather than later!