Getting the electronics to work on such a tight energy budget is a big challenge, very impressive! I've worked on a similar concept using a bistable display and

Getting the electronics to work on such a tight energy budget is a big challenge, very impressive! I've worked on a similar concept using a bistable display and a supercap for energy storage to recharge very quickly when sun is available. This is for more zen-like use cases, like chess puzzles: https://lightnote.cardonabits.com/products/lightnote-chess-edition https://lightnote.cardonabits.com/products/lightnote-chess-e...