I think epaper works in a similar way to lcd, ie appplying an electric field across some kind of reactive layer - polarizing liquid crystals, tiny charged colored spheres, etc?
I only ever see high-resolution epaper matrices, but in principle I think you should be able to have much simpler epaper segment displays and so on, just like for lcds. Is there some reason this is not a thing?
For this clock, cool as it is, lack of a backlight seems to limit it to being a desk clock. I can see a larger epaper display working well as a wall clock, but it would have to be much cheaper than a full high-resolution matrix display, hence my comment above.
> I only ever see high-resolution epaper matrices, but in principle I think you should be able to have much simpler epaper segment displays and so on, just like for lcds. Is there some reason this is not a thing?
This is a thing.
At home I have a couple Xiaomi "LYWSD02MMC" clocks that use e-paper segment displays. They also broadcast temperature and humidity over BLE and last a bit more than a year on two coin cells, and look (to me) much nicer than the Agora clock, they are much slimmer (about half a centimeter deep and with a smaller bezel).
They are proprietary and very much closed though (although you can control them without proprietary apps, at least).
Edit a few similar devices can run an alternative, open firmware and here's info on the eink segment display of one of them if you're curious: https://github.com/znanev/MHO-C401
I only ever see high-resolution epaper matrices, but in principle I think you should be able to have much simpler epaper segment displays and so on, just like for lcds. Is there some reason this is not a thing?
For this clock, cool as it is, lack of a backlight seems to limit it to being a desk clock. I can see a larger epaper display working well as a wall clock, but it would have to be much cheaper than a full high-resolution matrix display, hence my comment above.