So a few years ago I hacked up this sort of thing.

I bought a generic epaper display from aliexpress, a 5.8 inch 648x480 one that could do white/black/red with an SPI interface, then I wired that to an RP2040 board, then wrote a bit of circuitpython firmware for that which could receive commands over USB and draw stuff on the display.

I got as far as being able to send images to it, and writing a little host program on my PC that would do a partial screen update on a clock display and CPU/GPU temperatures once a minute, and draw a Mandelbrot set in the remaining space, with a full screen refresh every 15 minutes because it needed it, and a several minute “exercise” routine that would take every pixel from white to black to red and back to white at midnight, to improve screen appearance longer term.

And then I got bored/annoyed with it as the refresh was so slow (~30s for a red update) and the rp2040 needed me to manually press its reset button after every windows boot or the usb device wasn’t recognised. I thought about rewriting the firmware in C in case it was circuitpython that was flakey … but lost the impetus.