
Show HN: ePaper.js – Easily create an ePaper display using JavaScript and HTML - robocollab
https://github.com/samsonmking/epaper.js
======
sdfhbdf
Looks very cool and promising.

I'm wondering what's the power draw for the Pi with this one since it "Loads
index.html in a headless instance of Chromium, using Puppeteer". Isn't
Puppeteer quite a power hungry process?

Would it run on Pi Zero with a battery attached and how long would it last
with updates once a minute or once every 5 minutes?

I'm thinking about possible projects that would not have AC power all the
time, maybe something solar powered for a dashboard outside.

~~~
lukehaas
I built something that's similar to what you're describing, here's an article
about it: [https://www.hackster.io/lukehaas/e-ink-display-for-daily-
new...](https://www.hackster.io/lukehaas/e-ink-display-for-daily-news-weather-
and-more-3dd7b1)

It combines a Pi Zero with a 2000mAh lipo, updates every 6 hours and lasts for
around 90 days per charge.

~~~
taf2
Thanks I like the idea of a git pull on boot up.

------
Waterluvian
When using my reader, sometimes mutations require a full screen invert.
Sometimes stuff just seems to change trivially. What governs that? Is that
done by the display or driver or higher level code?

~~~
mekkkkkk
The problem with e-ink is that redrawing pixels without cycling leads to
ghosting after a few draws. Most displays automatically cycles the entire
screen now and then to mitigate this. I guess it's up to software or firmware
to detect when to do it.

~~~
robocollab
The Waveshare displays do support partial refresh, but I haven't had time to
look into exposing it into Node, yet.

