E-Ink UI - long term planning

[todd-herbert]

From what I've heard, off in the distance (more than a year from now) there are big UI changes planned. I know there's active work going into designing a "mobile phone" style UI, for some of the more powerful devices. This is all very exciting.

Because of their slow refresh rate, E-Ink displays have unique UI requirements, which will require special consideration. I also understand that the new graphics framework may be too resource intensive to run on some older devices.

My aim here is to start a discussion early, so we have plenty of time to work on solutions.

What role do you feel an E-Ink display should play?
What features do you feel are important in an E-Ink UI?
Do you have any technical suggestions about implementation?

[feh123]

I can comment on question one and two. On my meshtastic nodes I have only used the rak14000 e-paper module (B and W). I have used an e-ink screen for other raspberry pi projects. These require quite a lot of text to be displayed with additional icons and images. It handles these really well. This use does not require a fast refresh rate so it's prefect.
I use a rak14000 on a stationary node in my house to obtain weather date from a node in my garden. It's great for clarity of text and ease of reading. I much prefer it to OLEDs. I would like to use it for hiking but I cannot because I also use gps so the pins are not available. However I have some experience of it on a mobile node. The major advantage I see is that it uses far less power than an OLED. I have no measurements of this other than a comparsion of two identical nodes one with OLED, one with E-ink. It seemed the e-ink was using less battery (clearly real power measurements would be better than my indirect method). The clarity was better as expected, the only downside was in bright sunlight you need some way to shade the screen to read it.

[todd-herbert]

Thanks for sharing your experience! It's definitely helpful to hear that you're using it for weather data; points out that it's important to keep support for modules to display things like sensor data, which is something I might have otherwise overlooked myself. Also hear you that power-saving is a big thing to consider.

[markbirss]

@todd-herbert

Over and above the new UI discussion that started, there was also a Meshtastic forum member that posted about e-ink gui long while ago - https://meshtastic.discourse.group/t/new-ui-for-e-ink-display/3666

I also like the idea that one can reverse the e-ink display and instead do this

[todd-herbert]

I do like the idea of the reversed UI, I was even thinking about playing with it on a custom build later on.
Is it particularly unhealthy for the display to draw light-on-dark like this? I've always had the suspicion, but never actually looked into it.
I'll check out that discourse thread too!

[markbirss]

I also tried it out, just reversed the drawing and init color, with partial updates the display did tend to get dirty more quickly

[todd-herbert]

Maybe just a nice custom screensaver (drawn with full refresh) to compliment a dark enclosure 😉