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Show HN: E-Ink Day Schedule

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Re: Show HN: E-Ink Day Schedule

#121

Post by Fnoord »

joelthelion wrote: post #112
harlanji wrote: post #75

Earlier quoted context omitted.

WaveShare screens are very reasonably priced and are starting to have 3+ color options. Using a RasPi and Python one can simply display any image via Python Imaging and some code to transmit the data via the connector pins. The image remains fixed on the screen even when it's powered down. I got a little screen and the demo code worked, didn't know Python well enough at the time to keep running with it (part of the m…

Is there a way to use them in a low power setup, with a battery that lasts at least several days?

Yeah e-ink uses no power, only when it refreshes. If you refresh say from 7 AM till 11 PM but not in night then WLAN has to fire up (cheap on ESP32 etc) and you could easily use a poor man's powerbank such as 18650 in USB enclosure.

Tho I think PoE is neat for a device like this. White cable (assuming wall is white) and you're done.

Though I wouldn't rely on a proprietary solution. Nor on Google Calendar.

There are plenty of such options available. For example [1] but there's many more. Here another [2]. Can't find the one I got but yeah it broke and remember you need to update the software at times. I put it on a VLAN and guest WLAN to be sure.

[1] https://hackaday.io/project/189632-e-ink-weather-station-pum...

[2] https://www.hackster.io/lmarzen/esp32-e-paper-weather-displa...

Re: Show HN: E-Ink Day Schedule

#122

Post by pests »

jes5199 wrote: post #99
omershapira wrote: post #40

The most fun part of these projects is seeing people quickly build ad-hoc renderers for E-Ink. Very quickly you find out you need render passes, dithering, debanding, etc. Here's my weather E-Ink board (which consistently gives a faster result than waiting for the iOS weather app to fetch & render): https://github.com/OmerShapira/theres-some-weather-outside

what's the screen refresh time like on this? I have a small e-ink display that I got from Adafruit and it takes 10+ seconds to redraw

LTT just did a video[1] on an 25inch E-Ink display[2] that runs at 15Hz.

It worked way better than I thought it would and is a pretty decent size.

Little pricey.

[1] https://www.youtube.com/watch?v=-ZXrJRpA0Jw

[2] https://www.amazon.com/DASUNG-Paper-Monitor-Knight-Version/d...

Re: Show HN: E-Ink Day Schedule

#123

Post by giveexamples »

I've been using a magnetic pad (https://www.plus-vision.com/jp/product/kaite/) that works on the same principles of eink, except using magnets rather than electric fields. There's many variants available on aliexpress now. The only con is that stray magnets like on computers will wipe the pad if placed too close together.

Re: Show HN: E-Ink Day Schedule

#124

Post by omershapira »

jes5199 wrote: post #99
omershapira wrote: post #40

The most fun part of these projects is seeing people quickly build ad-hoc renderers for E-Ink. Very quickly you find out you need render passes, dithering, debanding, etc. Here's my weather E-Ink board (which consistently gives a faster result than waiting for the iOS weather app to fetch & render): https://github.com/OmerShapira/theres-some-weather-outside

what's the screen refresh time like on this? I have a small e-ink display that I got from Adafruit and it takes 10+ seconds to redraw

The one display I got takes about 2 seconds to cycle. You can make it shorter with partial redraws, but for my purposes, the cycle was the right thing to do.

Re: Show HN: E-Ink Day Schedule

#125

Post by ClassyJacket »

afavour wrote: post #10

An aside but I’ve long thought that if Apple was truly committed to the environment and equipment reuse they’d let us use old iPads for stuff like this. I’d love to make a digital photo frame/day planner from an old iPad mini I have kicking around. They could even integrate Siri etc. (I know you can get some way toward this with various apps but it’s definitely not the same as something OS-level)

My work does something like this with Surfaces and unfortunately if you leave devices like that plugged in all the time the batteries swell and bend the screen and frame.

Maybe they could soft lock them to 50% or something but under normal circumstances it's too dangerous.

Re: Show HN: E-Ink Day Schedule

#126

Post by Qwertious »

landgenoot wrote: post #59
politelemon wrote: post #9

I repurpose all my old ereaders (Kindles and Kobos) into displays for something, weather, agendas, some even do images (albeit very low resolution). It's great to have these around the house, quietly doing their thing. One thing I will point out from observation, the radios on ereader devices aren't great for heavy use; they were originally created for occasional syncing. Projects like these will require an HTTP requ…

I don't think the resolution is the problem with images on e-readers, but the amount of grayscale levels is. Dithering works brilliantly on these devices. I made a photo frame out of one of these by calling some imagemagick from golang.

Resolution is more important than grayscale for e-ink - not only are they two sides of the same coin for dithering, but e-ink renders far faster in black-and-white so with sufficient resolution you've got a snappier page turn.

Re: Show HN: E-Ink Day Schedule

#128

Post by nextaccountic »

konschubert wrote: post #96
loginatnine wrote: post #66

Earlier quoted context omitted.

I understand your desire to build out an "ecosystem" of app and everything, however, I'd really like an option to go fully on my own and skip your iOS/android app. Is it something that you plan on doing and document? Or is there an easy way I can ssh into the device and figure out on my own? TIA! EDIT : well, 1 minute later you answered part of my question here : https://news.ycombinator.com/item?id=37645339 . How ab…

ssh-ing is hard because there is no USB port. There isn't even an USB controller on the board, just some rudimentary UART pins. The usb plug is just for power.

How does it communicates with anything from the external world? This same channel could be used for sshing or anything

Actually, from another comment

> Privacy Information: Plese note that the data is proxied through the Invisible Computers API backend and a non-reversible hash of most recent image is stored for up to 48 hours.

So there's some mechanism to make API calls to your own cloud infrastructure, but customers can't use it to skip the middleman and send things directly to the device? I hope I'm reading this wrong, because that's awful.

Re: Show HN: E-Ink Day Schedule

#130

Post by konschubert »

pitched wrote: post #108
konschubert wrote: post #94

Earlier quoted context omitted.

> Why do you proxy eveything through your api backend Because it makes development and maintenance soo much easier, faster and reliable. I don't have to debug stuff that breaks on somebody's embedded esp32. If something breaks, it's in the backend and I see it in Sentry. > Can the device not check the url directly Yes, it could (with some modifications). But then you need to transmit and store the URL on the device,…

Instead of having your backend download and retransmit the file, you could return a redirect to it instead? Plus maybe lower the poll rate from a few times per minute to once an hour or so to avoid the need for caching to save battery.

I could do a redirect (it would require a small firmware update)

But that would still expose your authentication credentials to the backend, so a malicious backend could MITM you.

Reducing the polling is definitely an option, I want to make that configurable very soon.

Btw, the cached data in the backend is encrypted with a token that is only transmitted from the device to the backend during the API request of the device. It's not end-to-end, but it's a step.

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