Comment by sho_hn | Hacker News Reader

Comment by sho_hn | Hacker News Reader

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I've recently built a little "automatic newspaper" home deco piece using a 13.3" e-ink display, mainly as an excuse to try out Rust on an ESP32:

https://imgur.com/a/PqkhdGd (edit: corrected link to album with finished pics)

This is using an IT8951 EPD controller I wrote a little Rust driver for, which indeed talks SPI, although its SPI frontend is really a quirky/leaky abstraction over an I80 interface so you have to e.g. do chip select using I80 semantics and send preambles and such. Still, pretty breezy overall.

Can confirm the power draw is of course "bursty" during the update. Also, yes, e-ink refresh times get slower in colder temps. e-ink refresh also works poorly in direct sunlight. The displays can also "dry out" from it and it can cause artifacts. But the envelope for normal operation is overall fairly good, certainly for home/indoor use.

There's a fair amount of manufacturing tolerance and during testing manufacturers will usually record preferred drive voltages for the individual unit, etc. It's quite important to configure software to make use this information for optimal performance.

I'm hoping it will run for about a year without recharging from that little 1100 mAh LiPo pouch at one update a day (the newspaper is rendered on a common home server RasPi using LuaLaTeX+Ghostscript and then retrieved over Wifi), having taken self-discharge into account.

For more du-jour hype points I'm considering using OpenAI on the backend to summarize articles down to size to fit the layout! Or make it do style transfer to "1870 newspaper".

Looks great! Once you publish the code, please submit it to the Rust Embedded Showcase :)

https://showcase.rust-embedded.org/

I love it! On a somewhat related note, I've been working on a tiny Forth interpreter lately, and I think the e-ink device it could be an interesting choice to explore and test it on as a dedicated computational environment. Inkplate looks very appealing: https://soldered.com/product/inkplate-6plus-e-paper-display-...

You might want to check out Kagi to summarize articles: https://labs.kagi.com/ai/sum. It does the heavy lifting of producing nice outputs for you.

This is great! Would you happen to have the code available somewhere?

Not yet, sorry! It's still very fresh; I'll be releasing on GitHub pretty soon after cleaning it up a little and writing some documentation. When getting around to it I'll remember your comment and drop you a line.

https://github.com/eikehein/hyelicht <- I get a little obsessive with that when documenting/releasing DIY stuff ... :-)

Wow, haha, that's extensive. However, I'd urge you to release first and write docs later (or even release first and make it work later). I'd get a lot more value from code with no docs than no code at all!

I'll try to RERO!

When you finish, I’d love to see the code/documentation too!

That looks great! How much was the e-ink screen itself?

About $400 + shipping from Waveshare.

Thanks for sharing the price. The build looks really good, but $400 is a bit steep for anybody on a budget. I think a good quality (high coverage and pixel density) LCD with auto-brightness would be economically competitive, though of course not really the same.

Look into memory reflective lcd's, doesn't look quite like e-ink (and for quite a few of them you have to resort to dithering instead of proper greyscale), but they're considerably cheaper and offer the same power benefits.

Additional benefit is that they're quick to refresh, if you have an application that requires it. I have a calculator built with it, works perfectly.

Thanks! I have a watch with that type of display, not sure why I’d forgotten about it.

Ah, I see. I'm waiting for those to come down towards the $150 range before I'm likely to get one. But they look gorgeous.

What's the screen? Where did you get it from?

It looks really cool!

Thanks!

It's this product, which is built around a ED133UT2 panel by E Ink: https://www.waveshare.com/product/displays/e-paper/epaper-1/...

You can find this unit and other IT8951-based driver boards for it on a few different places/in different catalogs but Waveshare's easy and the price seems OK.

The ED133UT2 is a Carta 1200 display. The latest Carta gen is the 1250, but AIUI it's only relevant for color displays with the change being a thinner film that allow plastic color filters to be closer to the ink to improve contrast. I think the current greyscale 13.3" offered by E Ink's direct shop for $449 sans driver is still a 1200 - at least many vendors list VB3300-NCB as just an alternate name for the ED133UT2. The Carta range of displays are well-known from Amazon's Kindle and many other reader products, so my newspaper is basically a big honking DIY Kindle.

They also offer a 10.3" panel with even higher resolution for half the price of the 13.3" that's supported by the same controller and should be fantastic for all sorts of home dashboards.

Shoutout to the EPDIY project, which supports the ED133UT2 and is planning to support the 10.3" ES108FC1 in a future revision!

https://github.com/vroland/epdiy

This is extremely cool!

While cobbling together my project I was really tempted to go custom PCB with the ESP and the ITE controller on one board. Looks like this eschews the seperate controller entirely and instead uses ESP32 PSRAM for the framebuffer and has the driving waveforms embedded in the MCU firmware etc. Very neat, also one further level of "go deeper", would love to try one!

I worked with 7.5 inch screen a few years ago for a desktop Todo list, but the display faded overtime (1 year).

This seems to be pretty common with E Ink displays unfortunately (you hear the same about many commercial ebook readers). At least the larger ones are more or less all from the same manufacturer (E Ink). I don't know if there is binning going on and Amazon gets better batches than Waveshare does ...

Direct sunlight can also be a big problem for this display tech, so I'm intentionally hanging it on a wall facing away from the most intense daytime sunlight I get.

Hope it survives at least a couple of years.

Wonderful thank you! The 10.3" looks like just the stuff. Heck, the 7.3" is under $60!

Thanks for the info!

I saw something like this a couple of years ago and wanted to do it myself. However the cost was relatively unattainable at the time, I'm glad to see it is getting more affordable!

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