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Comment by NikxDa | Hacker News Reader

This is super cool, and I wish something like this existed at my place, as it enables information sharing without the need for phones/actual screens that shine in your face when the lights are low or tempt you to doomscroll.

That said, the large primary display this uses is $2000. That's very hard to justify for any "normal" household, and that's without any mounts, backend, services etc.

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I made this thing [1] for us, it uses a cheap 10" e-paper display off aliexpress, an ESP32 and a couple of I2C sensors. The case is 3D-printed. It runs on two 18650 batteries, and all in all it cost less than 100$. The OpenWeather API is free for personal use.

[1] https://mjones-foui.no/img/wall_clock_1.png

hi I've been interested in doing something like this for myself, what tools and software did you use?

+1, and have you tried running 2 displays side by side ? That should give you an effective diagonal of 14 inches or so, and for those displays, cutting it in two does not really affect the utility of the display (likely tabular content anyway).

Seems like the author has experimented with 2 kindles side by side.

I built this weather dashboard specifically for colour EPD https://github.com/mt-empty/pi-inky-weather-epd

I source most of my components from aliexpress. It's been a while, but these are the components I used:

Microcontroller: FireBeetle 2 ESP32

Display: Generic 10" e-Paper display with driver board included

Timekeeping: DS3231 Real Time Clock Module

Temperature and humidity: BME280 module

Charging: Type-C USB 2S Li-ion BMS

That, along with a breadboard, two 18650 batteries, some resistors and capacitors make up the hardware. I modelled and 3D printed the case. I used the PlatformIO plugin (available for VSCode-based IDEs) for programming and transferring code to the esp32.

Weather API: https://openweathermap.org

For actual firmware I'd take a look at matada's github for inspiration (see the other reply in this thread). My own code isn't of the photogenic sort.

I need to know why the opposite of 'rain' is 'yo'.

yo it's time to go out!

Seems the sun is the one saying "yo", perhaps as a form of a greeting as it was raining the days before?

I'm just guessing, but I think it might simply just be for fun :)

The sun is greeting you! I drew these freehand, kind of quickly. And while I personally like the style and think it's a good fit for us, I did intend to make several sets of weather icons. At the very least I need to make the sun symbols adapt to the seasons - we don't really have a full sun during the darkest months of the year where I live.

Love those weather icons. Personality in software design is underrated.

Thanks! I intentionaly made the weather symbols somewhat "childlike" to give it some personality and also make it obvious that it's a custom device, and not some off the shelf gadget. Works well as a conversation starter!

Nice! Do you think it would be easy for someone with no hardware experience to build one?

If you already have Home Assistant running, I think it should be simple. Most of the time you can buy devices with pins already soldered and it's just the matter of connecting them together. AIs are pretty good with ESPHome configs. You can even take a picture so that they can help you identify the correct pins. Some coding may be required for drawing things on the display though.

Yes, I think so. Electronics prototyping is so accessible now, and there's such a deluge of inspirational projects out there to learn from. YouTube is a gold mine, and I'll leave links to a few channels I follow, below.

If you get an Arduino or Esp32 microcontroller (maybe in one of those starter-kits with various sensors), some breadboards, assorted jumper-cables and a kit with electronic components (resistors, caps) you'll be good to go. A device like a wall clock most likely won't require soldering, since it won't be jostled or moved around much.

Ben Eater: https://www.youtube.com/@BenEater/videos

Paul McWhorter: https://www.youtube.com/@paulmcwhorter/videos

Huy Vector: https://www.youtube.com/@huyvector/videos

I'd also take a look at the other DIY projects that people have linked in this discussion.

OpenMeteo is pretty amazing too, and doesn't require an account or API key, which is nice.

I incorporated OpenMeteo into a project recently and got frustrated with their aggressive rate limiting. If in the US, weather dot gov has an excellent, free API. Or, OpenWeatherAPI which works internationally and has support for more things that weather dot gov does not. OpenWeatherAPI will also synthetically provide weather data based on their models if there is missing station data

Using your own weather station is another option

> I incorporated OpenMeteo into a project recently and got frustrated with their aggressive rate limiting

Which one? They seem to do 600 calls / min, 5.000 calls / hour, 10.000 calls / day, 300.000 calls / month, how many times do you need to look up the weather for personal use? Fine, maybe you want 3 different locations, you can still call each of those sufficiently with those rate limits, no?

a redis geospatial index + redis distribution locks you can build a performant cache layer that is consumed by a ton of people and stay well under that rate limit.... the weather data only updates every 5 minutes too, so you can use that for your cache ttl.

I have to sample multiple lat/lon across the world all at once

For what purpose? And multiple times per hour for each of those? Sounds like not a personal project already.

It’s for a hobbyist project and non commercial use.

Right, but less "I want to know what the weather is locally and maybe in my summer house" and more "I'm curious about sampling global weather/temperatures", right? I don't think the intention of the API is for the latter, but more for the former.

You might be interested in knowing about https://trmnl.com. No affiliation beyond interest in buying a few in the future. They have a 10.3" version in the works.

Good thing about trmnl is you can run the entire backend if the company disappears.

Looks good, the refresh rate... does not! 200ms for partial refresh, ouch.

The ease of integrations might make up for it, though.

is 200ms actually an issue if you're just using it to display static content?

Nope.

You can make smaller ones for much much less. I’ll post pics of mine a bit later but waveshare 7.5” display in a photo frame and almost any ESP32 dev board and you are set for less than $100 (along with suitable HomeAssistant and ESPhome infrastructure to support it). The original article is a very slick bit of work, so well done

The article also mentions using jailbroken kindles which I assume should be the cheapest way to get a decent sized epaper screen with builtin connectivity.

edit: https://github.com/sibbl/hass-lovelace-kindle-screensaver

Yep, it’s super cheap. I wrote about mine here:: https://franz.hamburg/writing/kindling-e-ink-dashboard.html

You can also buy some for less than $100.

I can vouch for the reTerminal: the build quality is excellent, and they come with a battery, sd card reader, and some sensors: https://www.seeedstudio.com/reTerminal-E1001-p-6534.html

Gonna piggyback here to second this and chime in to say I went with the BYOD screen linked within your link for $49 (SKU 104991005). It's definitely more barebones and probably not even as cost-effective if you're still planning on buying the "lifetime" TRMNL API access.

I don't have easy access to a 3d printer, so I just have mine sitting on an extra phone stand I had lying around that can be had for a few bucks from Amazon.

I couldn't be happier with it and am thoroughly enjoying my complacent, lazy solution :)

FWIW you need to pay for the trmnl key ($50) to use your own device with their servers, but if you run a server yourself you don’t need to pay.

I’m very tempted, a lot lower resolution than a kindle but it’d be pretty cool.

i could have been clearer about that. but yeah, even for what i paid, i was happy to immediately be off to the races designing the couple panels within their web portal and having something functional and useful to me without any real friction from having to figure things out.

moving on to the self-hosting side is probably now backburnered indefinitely, even if i do have some grander ideas in the longer term. unfortunately, i'd need more than a weekend project's timeframe to bring them to fruition.

you can point a higher def Kindle to TMRNL, either our closed source web app or free to an open source server.

https://github.com/usetrmnl/trmnl-kindle https://github.com/usetrmnl/trmnl-koreader

OP's Timeframe looks rad, but yes on the pricy side. check out trmnl .com for smaller / less expensive options and self hosted options. (disclaimer: i'm on the team)

Yo Ryan! I get your emails! I was just reading this thinking “man he should’ve tried TRMNL”

I love my original one and am planning to get a model X when budget permits

I’m a big fan of TRMNL! The big difference with the Boox device is real-time updates, which make the smart home status information much more useful.

thanks for the support and i hear you. a few folks pointed their Boox at TRMNL[1], and we’re finally in the smart home arena now with free 5 min refresh rate for Home Assistant. aiming for JIT refresh by summer.

1. https://www.reddit.com/r/Onyx_Boox/s/ZSLF7u5pm8

lol, €17.95 for a Developer "Unlock"[1].

[1]: https://shop.trmnl.com/products/developer-edition

That's just a perpetual license to use their hosted server. You are free to use your own self hosted server for free.

They should really clean up the phrasing because it sound so sketch, like they're locking device features for money, turns people off easily.

what do you think it should be called? for ~$15 optional one time bucks people get 24/7 access to the entire engineering team, me, prioritized feature dev, and can earn monthly payouts from our Creator Fund. we don’t charge a subscription, obviously i’m partial but this model has serves us well. and most of the developer edition fee goes right back to the community via bounties, perks, etc.

Developer Access or something like that, and put part of your comment in there. I would remove the word Unlock entirely, it implies you’re locking code, as opposed to providing a service.

we call it Developer Edition, i think this is functionality the same. https://trmnl.com/blog/developer-edition

I think you’re mixing that up with the byod key, this is a different thing.

bought trmnl & have been sorely disappointed with the transparency regarding self-hosted options & the availability of functionality. Was led to believe Hanami BYOS was identical to the hosted server. have opened a ticket, have had others voice the same sentiment. I appreciate the effort, but lament the reality of TRMNL & the marketing.

you can import ~700 plugins from core to Terminus (Hanami build) or the Laravel build in 1 click. maybe you came on board before that was a reality. we and the community have been rapidly developing multiple self hosted servers with all kinds of features and in different frameworks for comfort. in no marketing materials have we ever claimed that OSS clients were the same as the main web app. in fact that’s why we offer a BYOD license for the web app only. we’ve invested hundreds of thousands into open source so that people can get the TRMNL experience without paying us a penny.

My solution was to buy a used Samsung tablet with OLED screen, and control the display on with motion sensors. It sits in the hallway, above the keys drawer. The screen is on only when someone's walking nearby, and around eye level when you go pick up the keys. Designed the dashboard based around muted colours on black background, with brights reserved for "hey pay attention to this" data. And most importantly, the screen is not visible from any spot you're likely to stay at for a longer time. As for mounting, I used calipers, 3d printer and some double sided tape. It's not completely seamless, but damn close for ~10% of the effort.

Would love some details how you enabled controlling the display with motion sensors.

The tablet itself runs https://www.fully-kiosk.com/ to display a web dashboard. Fully Kiosk has good Home Assistant integration, including screen on / off controls. I also have a bunch of Sonoff battry operated zigbee motion sensors scattered around the place. Then Home Assistant does what it was meant to do - act as a glue layer between various systems, firing screen control commands to Fully Kiosk as a result of select motion sensors triggering.

What's the software stack? Did you write an app for it? Jailbreak it?

No jailbreak necessary - the tablet runs https://www.fully-kiosk.com/, and displays a web dashboard.

The dashboard itself is a react app talking to my Home Assitant instance over a websocket. The heavy lifting of bringing various data sources together is done by HA, I just wrote a react app because it seemed easier than learning to customize HA dashboards to the degree I wanted to.

I did a similar thing with a regular backlit computer screen.

It automatically shuts off after 30 seconds of inactivity.

I added a $3 webcam, and use openCV to detect motion. If three consecutive frames (sampled 0.5s apart) are each sufficiently difficult from the previous one, it attaches a virtual USB mouse, then moves it one pixel.

This wakes up the display whenever you walk past, then puts it back to sleep again when you stop moving.

The motion-detection pipeline uses less than 0.3% CPU on an intel N100 (6w TDP).

You can probably just use a cheap motion sensor instead of the webcam if you wanted to. There so many now

If you have some to suggest, I'd love to hear it... TIA!

What's your budget? https://en.tokyodevices.com/items/128

But seriously you can probably DIY something a lot cheaper.

Something like LD2410 [0]. IIRC there's newer ones that report accurate position and even heart beat rate, but I've forgotten the names of those..

[0] https://dronebotworkshop.com/ld2410c-human-sensor/

Here’s one

https://thepihut.com/products/60ghz-mmwave-breathing-and-hea...

Same kind of tech but higher frequency.

> The MR60BHA2 is a 60GHz wave sensor that detects breathing and heartbeat patterns. Using its radar technology, it can monitor vital signs without direct contact, even through materials like clothing or bedding. You can use it for sleep monitoring, health assessments, and presence detection.

This is kind of crazy, I had no idea this was a thing. And here I have PIR sensors all over the place and hacks around those, that definitively sounds much better. Besides being more expensive and weaker range, any drawbacks for using it for motion sensing?

Found a few aliexpress sellers offering LD2410C's, but all cost 30% more than the webcam I used.

In Czechia we have LaskaKit which is ESP32-based board with a GoodDisplay e-paper. It works perfectly with ESPHome and Home Assistant. :) https://www.laskakit.cz/en/laskakit-live-7-5-e-paper-stavebn...

There are a couple of options for a large, non-backlit, low power display that are less expensive than the e-ink monitor they're using. One is the Samsung EM32DX, a 32" color e-ink digital sign for <$1300 (<$1000 if you can find it on sale) but it has a long refresh time. The other is the SVD rE 32" reflective LCD monitor for ~$1000, but it needs to be in brightly lit rooms because of its low contrast.

In my post, I talk about how QHD was not high enough resolution for usable text rendering at 32". The SVD monitor is even lower resolution, just 1080p. I'd love to see a true 4k SVD product but I'm guessing it'd be even more expensive than the Mira Pro.

There are lots of other eInk devices you can use LVGL with.

ReTerminal and other derivatives from Seeed Studio are two options. Seeed even has a newish color unitfor under $250 [0].

Not trying to diminish all of the thought and work that's gone into OPs project but a lot of this has been available to do in HomeAssistant for quite some time. Glad more people are finally seeing the value in eInk like this. I've been using them for a while in my office and bedroom for simple status as the OP states: only showing certain status depending on state.

The other unit I tinkered with quite a bit of is the Heltec Vision Master E290 [1] which is a 3" eInk devices for under $35. Based on ESP32 and has LoRa.

[0] https://www.seeedstudio.com/reTerminal-E1004-p-6692.html [1] https://heltec.org/project/vision-master-e290/

Approach the expense like a business. Save up for expense, but more than that, look at lost revenue due to time lost to doom scrolling. If you're able to be more productive or having it results in more productivity, can you said to not get it?

That said, $2,000 is for one at that size. You could get a e-reader and root it for way less. It would be smaller but would be correspondingly cheaper.

I have a similar setup at home with a homemade dashboard. It's less polished and I've never implemented smart home (don't use any smart home devices) but it's calendar, weather, air quality and subway alerts. I also took the tack of building the UI with Bootstrap 3 so that it will run on any of my ancient devices like a gen 2 ipad air. I did it as much to usefully recycle old screens as anything else.

Home assistant is great even if you don't have devices. It can get data from all you calendars weather and such.

e-ink is low-power and easy on the eyes. But for a cheaper project recipe:

    * repurposed old LCD rotated to portrait mode
    * Raspberry Pi 400
    * Debian with Sway showing various tiled terminals/browser windows
    * self-hosted REST server that collects/provides data to display

If you go the image-rendering route for e-paper, Sharp (the Node.js libvips binding) is surprisingly good for this. You can do grayscale conversion, resize to the exact panel resolution, and apply Floyd-Steinberg dithering all in one pipeline with minimal memory overhead.

The trick with e-ink displays is that naive grayscale conversion looks terrible because you lose all mid-tone detail. Dithering the image down to 2-4 levels before sending it to the display makes a huge difference in readability, especially for things like weather icons and charts. ImageMagick can do it too but Sharp is about 4-5x faster for batch processing since it avoids spawning subprocesses.

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