Thanks for sharing, maybe it's time to buy some more old Kindles... I use bunch as smart paintings (with changing pictures generated locally with stable diffusion), and of course Home Assistant dashboard. They are awesome little machines.
Look at CrowPanel, you can get nice e-ink devices made for development, at a reasonable price. I have a small 2.13in esp32 board, I spent some time yesterday making it into a pocket flashcard device for my German courses. The energy consumption is minimal, small form factor, easy to flash via esptool or arduino utils
Thanks for the tip, I've seen those small e-ink display on sale in Aliexpress, but wasn't sure about their quality. Maybe I'll get one for my next project, I can see many use cases.
I didn’t notice any quality issue. And the crowpanel docs and demo repos make it simple to quickly get results. Though I had troubles getting macOS to establish a serial connection, no problem under Linux and windows