Show HN: E-Paper 7-color display showing the current weather

by blixt • 2 years ago

229 93 2 years ago

A hobby project of mine that was surprisingly easy to put together! I love waking up and seeing the freshly generated image.

illuminant• 2 years ago

Nice work! Beautiful use of the display.

slig2• 2 years ago

Beautiful. The prompt in the GH repo is the same you used in your custom GPT?

thih9• 2 years ago

First prompt: https://github.com/blixt/sol-mate-eink/blob/1236dbb66b80c838...

Get the weather data for {location}. If the location is not on Earth (fictional or otherwise), pick the place on Earth that is most visually similar to the location. Before you get the weather, reason about which temperature unit is most likely to be used at the location in question. That is the temperature unit you should use when getting the weather.

Second: https://github.com/blixt/sol-mate-eink/blob/1236dbb66b80c838...

Here is the weather for the location "{location}":
{weather["status"]}
Use Dall-E to generate a beautiful illustration of the location in the style of a wide post card filling up the entire image. Try to describe a scene that is iconic and aesthetically pleasing for the location specified above, but also one that can showcase the weather. (…)

blixt17• 2 years ago

Since GPTs only have the one prompt I had to specialize it for a multi-step process with tool use (since it has to call an endpoint and draw an image in one go). Here's the prompt that I use in the GPT:

https://gist.github.com/blixt/44bbed23bee7f65b53fd3304781edd...

slig2• 2 years ago

Thank you very much.

rlv-dan• 2 years ago

Really nice color palettes. Some reminds me if MUI on the Amiga.

edent• 2 years ago

I'm struggling to work out why this uses AI for getting the weather?

There are dozens of different free weather APIs which could be called directly.

blixt17• 2 years ago

It uses AI for some things you can't really use free APIs for:

- Turn a colloquial name for a neighborhood into the exact latitude and longitude (I'm sure there's some API that can kind of do this but I don't know a free one that is as accurate as GPT)

- Adding to the previous point, if you say "Hogwarts" or "Tatooine" it will dutifully give you the weather of those too thanks to AI [1]

- Most importantly, write a Dall-E compatible prompt to generate an image with the actual weather conditions (and sun/moon etc)

[1] https://x.com/blixt/status/1724099967361462714

gandalfgreybeer3• 2 years ago

Of these, only the first one actually has any real value. And as you've mentioned there are likely less "expensive" ways to do so. By expensive, I mean this is essentially using a sledgehammer to crack a nut (especially the Dall-E call).

itishappy4• 2 years ago

From your first point, I'd expect you to be using a service that provides the weather for a given latitude and longitude.

From your second point, I'd have expected that to fail for Hogwarts or Tatooine.

Taken together, it sounds like you're blindly trusting the coordinates generated by AI, and will happily generate correct-looking results for any input. I'd call that hallucinating the weather. If I type in "Springfield" I'm gonna get results but I'm not gonna know if they're mine.

This may be an unreasonable level of concern for a fun app.

rideontime• 2 years ago

Moistere Vapeers, very believable.

prmoustache• 2 years ago

Or you can just look at the window.

gandalfgreybeer3• 2 years ago

When I look at the weather app, I don't need to know what the weather is now but what the weather will most likely be later when I'm outside.

dylan6042• 2 years ago

My favorite is the weather station consisting of a rock sitting in a dish suspended by a chain. If rock is wet, it is raining. If rock is moving it is windy. If you can't see rock, it is night. If rock casts a shadow, it is sunny

blixt17• 2 years ago

I appreciate that it's just a nice picture that happens to update with the weather, but there's no reason to only use this for your current physical location. It accepts any place in the world (and also fictional places), so you could see a picture of what it looks like where your distant family member or friend is, among many other things.

callalex• 2 years ago

It’s a very useful line to have on a CV.

mikepurvis2• 2 years ago

“Don't leave the same image on the display for too long.”

Why is this? Is it something particular about colour e-ink?

blixt17• 2 years ago

The recommendation from Waveshare is "refresh at least once every 24 hours"[1]. It's probably not such a big deal in reality, but maybe there's some risk of the pixels getting stuck if they are active for too long?

[1] https://www.waveshare.com/wiki/7.3inch_e-Paper_HAT_(F)_Manua...

mikepurvis2• 2 years ago

Are they “active” when set? I thought part of the point of e-ink was that it would maintain its image without power applied.

Animats2• 2 years ago

Because it burns in, or because it fades out?

MissTake• 2 years ago

There a difference in how the display works that’s different to a monochrome one, that requires the caveat of “don’t leave the same image on the display for long”?

If memory serves, standard monochrome e-ink displays don’t suffer from burn-in.

blixt17• 2 years ago

I'm just parroting Waveshare's own recommendations[1], but yeah probably it's not such a big deal. I'll link their docs in the README to help people make a more informed decision.

[1] https://www.waveshare.com/wiki/7.3inch_e-Paper_HAT_(F)_Manua...

butchlugrod• 2 years ago

I use the Inkplate 6Color for some similar projects. Built-in ESP32 controller, so no Pi required. Can be fully battery-powered, so if you make intelligent use of the deep-sleep/wake schedule, you can stretch that battery charge for a couple of weeks. My favorite one is a red "On Air" sign that hangs on my office door (used for meetings and recordings.) I just trigger a shortcut on my Mac and it automagically updates my status and mutes my devices. They have example open source projects for weather displays, news, Google Calendars...

https://soldered.com/product/inkplate-6color-color-e-paper-b...

Cheap e-ink projects are super fun and useful.

blixt17• 2 years ago

Nice, super clever use of it! Yeah it's super fun and makes me want to put these screens all over my house.

localfirst• 2 years ago

holy crap! this hits all the checkpoints

edit: shocked at the prices!

declan_roberts• 2 years ago

All of the cool e-ink projects I want to do fall apart when I'm reminded of the cost of e-ink panels.

megablast2• 2 years ago

He said it is cheap, so don't worry about the ridiculous price.

Meanwhile you can get an esp32 + 2.8" tft screen + sd card for $15.

yshui• 2 years ago

I have a similar project too! I have an e-ink display connected to a Pi Zero that shows just a "Yes" or "No" telling me if it's going to rain outside in the next three hours. (On a second thought, maybe I don't need a 7 color display...)

My display is this one: https://shop.pimoroni.com/products/inky-impression-7-3?varia... which seems to be cheaper.

NoMoreNicksLeft• 2 years ago

I suppose I don't understand how colors work on e-paper at all. Can these 7 colors not be dithered? Or even mixed more properly, for something like true color functionality?

blixt17• 2 years ago

I use Floyd-Steinberg dithering, and if you look at the "More images" section you can see it does a reasonable job at representing colors. Also worth nothing that 2 of those 7 colors are black & white, so questionable naming perhaps.

I'm pretty sure real production use cases of these screens don't tend to use dithering though, focusing on contrast and readability.

Qwertious2• 2 years ago

The naming is a hard problem - black/white/orange and black/white/red screens are commonly called 3-color screens, to distinguish them from normal black/white screens. Calling them 1-color screens would be an awful choice of name, but "7-color screens" is a name consistent with the "3-color screens" name and calling them 5-color would be horribly confusing (especially since current 5-color would become 3-color).

Also, black and white are their own specific primary colors, they're not made out of a combination of other colors, so it's rather appropriate to call them colors in that context.

koolala2• 2 years ago

Does your room have a window? i am trying to understand the earth

blixt17• 2 years ago

I love windows! And doors. And pictures that update in response to the weather.

koolala2• 2 years ago

Like a news paper that get tossed right through your window onto your desk! I love all those too thank you!

move-on-by2• 2 years ago

The e-ink review say the display has a dark purple color. How is your experience?

blixt17• 2 years ago

I asked it to generate the weather for "The Purple Forest" (Narnia) and this is what it came up with:

https://i.imgur.com/kmKiqbO.jpg

You can zoom in on the purples. I would say it looks like a wine purple IRL.

dh-g• 2 years ago

Wow, these have come a long way.

move-on-by2• 2 years ago

I’m sorry I was not very clear with my question. The review is negative- saying the ‘white’ is more like a dark purple color. I’m not asking how well it shows purple- but the general quality of the display itself.

edpenz2• 2 years ago

The black does have a purpleish tinge on my panels, but the other colours don't. Overall it's pretty low contrast and saturation, and unable to reproduce cyan or fuchsia even with blending through any kind of blending, which makes certain things like sky and water come through poorly.

I made a palette for colour space conversions for reference: https://imgur.com/a/2vgFsT4

germinalphrase• 2 years ago

What are the power requirements for the build? Could it be run off one or more 18650’s?

blixt17• 2 years ago

If using the Raspberry Pi 5 I wouldn't go for a battery-powered solution because it's pretty power hungry. But you can run this screen just fine off of a Raspberry Pi Zero, or ideally a microcontroller if you want basically no power draw while it's sleeping. I was just lazy.

edpenz2• 2 years ago

The similar project I'm working on is looking like it'll get about a year of battery life with a typical 18650, the 5.65" version of the display and run off an ESP (refreshed once a day).

doakes• 2 years ago

I never realized just how thin these displays are. Very cool!

kfogel5• 2 years ago

Does anyone know why projects like this always seem to specify using a particular type of tiny, low-power computer (usually a Raspberry Pi or something similar) to drive the display?

I already have plenty of non-tiny computers that run Debian GNU/Linux. Suppose I wanted to run an e-paper display from one of those computers, using this code, just via a normal USB cable. I could do that, right? There's no reason I would have to use a Raspberry Pi or something similar?

joezydeco2• 2 years ago

There's no reason at all. RPis come with lots of bootstrap documentation and code so it's comfortable for someone that's played with Linux to get one running, install some packages, and make it do something.

You could do this with a tiny microcontroller if you had the time and knowledge to do it. There's nothing magical about the displays other than strange supply voltages at times.

The more common problem is that they don't listen to USB. They take SPI or parallel digital interfaces to set the pixels. So you need some kind of intermediate interface and software to draw the display. Which is why people just slap an RPi into the mix and talk to that over more common protocols.

kfogel5• 2 years ago

Thank you. My idea was more the opposite: do it with a normal laptop or desktop computer driving the display, rather than a tiny microcontroller. I guess I'm assuming that either the display's USB input supplies enough voltage to run the display, or that the display has a separate power supply -- i.e., that there's nothing magical about a Raspberry Pi that makes it supply special bits or special voltages to these displays that can't be supplied by, say, my desktop computer.

jrussino2• 2 years ago

My first thought for a project like this (grab photos/data from the internet, display them on a device) would be a Pi Zero 2 W or a Pi Pico W, for the reasons you stated.

I'm not particularly up to date with the tiny microcontroller ecosystem - if I wanted to execute this at lower cost and/or lower power, what would be some better options to consider?

bloggie• 2 years ago

Small computers like RPi make it easy to access the low-level peripherals such as SPI, which this small screen uses, and others like GPIOs. If your big-computer has such peripherals available to the OS, you can use them also. Before small computers, you could use the parallel port (and some small program) to talk to your own peripherals via the same low-level signalling.

kfogel5• 2 years ago

Got it -- I appreciate the explanation.

Animats2• 2 years ago

The other extreme would be nice. Something very low powered that can spend 99% of its time in standby. Then you could run the whole thing on a battery for months. For a weather display, waking up for a few milliseconds per minute should be enough.

The 7" E-Ink display is US$86, which is not too bad.

megablast2• 2 years ago

Because they are cheap and run on battery for a long time, and it is stupid to leave a computer running this display on.

jrussino2• 2 years ago

Thanks for posting! I picked up two of these same displays after seeing similar projects here that used them:

- "A WiFi color eInk picture frame" https://news.ycombinator.com/item?id=35689706

- "Color E-Ink Display Photo Frame Pranks [Mom]" https://news.ycombinator.com/item?id=26977747

I was planning to turn them into color photo displays like in those two examples, but this is a neat application too.

blixt17• 2 years ago

Thank you for sharing – I love that the second one also has a microscope closeup of the display while it's changing. Happy hacking, hope to see your projects on here soon!

skrebbel• 2 years ago

Totally off topic because this is v cool, but what’s the use case for things showing the current weather? Forecasts I get, but current? Lots of phones and even Windows 11 prominently display this information but who is it for? People who work in windowless offices or something?

I mean it’s a bit like a restaurant menu app that only shows you pictures or what you just ordered, right?

ImPostingOnHN• 2 years ago

Many taller buildings don't have a way for you to step outside in an outfit to see if it works for the weather. Or to step outside for a few minutes to try to manually gauge the temperature with our squishy body thermometers.

If you know the temperature, you don't need to do this exercise at all, you simply know based on experience, and it's more accurate, too. A few degrees difference can mean different clothes, different materials, different layering, etc.

advael3• 2 years ago

Cool hardware project and idea, but I'm not touching an OpenAI API with a ten-foot pole, especially for an always-on device

Maybe when I need a fun project I'll make a version that uses OpenStreetMaps + LAN-hosted Stable Diffusion tho, so worth a bookmark to remember to do that

stavros4• 2 years ago

What's wrong with OpenAI APIs and always-on devices?

advael3• 2 years ago

Trickly cost center a corp that's already betrayed me multiple times gets to set the price on. Also I have a hardline policy that I won't interact with Microsoft in any capacity for less than $80/hr, and that's the friends and family discount

stavros4• 2 years ago

OK this is uncanny, I independently made the exact same thing with the exact same display a week ago:

https://imgz.org/iBLADkCU.jpg

It's a frame that fetches the current weather and time at a location, has AI generate a photo with that location, and shows it.

How did we both independently arrive at this? I guess it was the most obvious thing to do?

djbusby• 2 years ago

This is a case where ideas are "all around" - it's the kind of example that's wonderful for a new entrepreneur - to see your idea isn't unique (very few are). Execution matters.

Y'all like the Uber and Lyft of eink weather - but I've tagged others like this from HN.

Edit: soon as I find the time I'm building one too - all are inspirational for esp32 dev + key for FOSs home-automation

securam• 2 years ago

$86 for 7-colour 7.3" RPi compatible e-paper display. That's not bad.

freedomben• 2 years ago

Neat, thanks! What a great project, and like any excellent project it helps get somebody on a path to customization. The hardware recommendation and even just epaper.py[1] is nice to see as a reference. Thanks for sharing!

[1] https://github.com/blixt/sol-mate-eink/blob/main/epaper.py

brunoarueira• 2 years ago

Congrats, it's awesome! I've starred the repo to use some ideas.

card_zero• 2 years ago

"Stocckholm". Also Santa Monica has at least one giant man, and on the beach there's a centaur, but I guess these little glitches add to the entertainment value.

serial_dev2• 2 years ago

The image displays Barcelona with 26°C and 2°C.

I've been to Barcelona a couple of times and it's hard to imagine a day where you hit both temperatures?

Is the weather data in any way reliable? Or is it all just hallucinated stuff and I should just enjoy the animations? It could also be that I know Barcelona weather less then I thought and it's possible to hit 26 high and 2 low?

blixt17• 2 years ago

Yeah this is Dall-E incapable of cleanly writing text. The 2 C is just a “hallucination” from the 26 C. This is a hobby project and as such I prioritized the text looking unique every time (and usually more artistic than in that image), rather than put a traditionally rendered text on there, but image generation models are not good enough for this use case if you were to make a serious product out of it.

serial_dev2• 2 years ago

It is certainly beautiful, would be good if it was correct, too :)

atoav• 2 years ago

I mean cool and all, but as an electrical engineer literally shaving off microamps from my design I can't help but wonder what the energy use behind the AI-generated backdrops is. After all we have kinda a situation as a planet.

Show HN: E-Paper 7-color display showing the current weather

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