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Show HN: I made a solar-powered, ePaper photo frame

27 points by jamez ↗ HN
Looks like this year ePaper projects have been popping around[1], so this is mine.

I made a photo frame with the intention of having a record of my family's history that can potentially outlive me. Knowing the challenges of long-lived digital projects, I consider this a moving target that will go through several iterations, but the first version showed encouraging results.

I wonder if anyone else is interested in having something like that in their living rooms.

More details: https://www.jamez.it/blog/2020/12/17/made-epaper-solar-powered-digital-photo-frame-call-solarpunk/

[1] https://news.ycombinator.com/item?id=22628348 https://news.ycombinator.com/item?id=22831323 and more recently https://news.ycombinator.com/item?id=25400702

12 comments

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pcdoodle
Cool project! The ARM cpu is way overkill but gets easy setup points. You could probably get away with a hidden Peltier to harvest the room vs wall temperature difference if you switched a ULP core in many of the wifi micro controllers on the market. Thanks for sharing.
jamez
Thanks for the suggestions! Thermoelectric energy harvesting never even occurred to me. Definitely looking into it.
captn3m0
+1. An ESP32 can fetch the image, display it, and go to deep-sleep with a much lower power output. The battery will last longer, but getting it much further is harder because electronics will degrade as well.
bert2002
Always tried to make the ESP32 fetch an image, but never succeeded (with Arduino though)
stevekemp
I setup an ESP8266, (wemos mini-d1), to fetch a remote image and display it:

https://steve.fi/hardware/d1-epaper/

It wasn't easy as I couldn't get GIF/JPG, or similar, working. As the library I was using used a buffer my RAM usage was twice as much as expected. In the end I used a simple home-made RLE-kinda image encoding. Then I'd stream those updates.

sxp
Very nice. I'm a big fan of these types of "perpetual motion" computers.

The project reminds me of https://developers.google.com/gdata/articles/radish which was a solar cell + LCD system that showed who had booked a conference room. It had to use LCD because e-paper wasn't feasible in 2008, but someone could do something similar now with e-paper.

> I’d like to find a vendor who could help me design a one-piece panel that would go all around the frame, which should decrease complexity and increase efficiency. It would also be nice if the panel was black, so as to nicely tie together the white of the mat and the grayscale of the image.

If you opted for a black border, could you put a slightly tinted piece of glass on top of the solar cells to make them look like a generic piece of glass instead of solar cells? You would lose incoming light, but the aesthetic improvements might be worth it.

jamez
I was not aware of that Google Calendar display. Very nice, thanks for sharing. Re: tinted glass on top of the border, it's an interesting angle, although I'm not sure I want to completely remove the look of a panel from the picture. Solar panels are cool in their own right: it's mostly in the domain of colors and proportions that I'd like to strike a Right Balance.
purplecats
I'd pay a 100$ to make this load a website every hour/day
jamez
The part about displaying a website every day is trivial, though that budget will not take you very far for a decently sized ePaper panel. Here's hoping that prices will go down in the future...
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