[HN Gopher] E-Ink Magic Calendar that runs off a battery powered...
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       E-Ink Magic Calendar that runs off a battery powered Raspberry Pi
        
       Author : edward
       Score  : 636 points
       Date   : 2021-10-03 20:59 UTC (1 days ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | tomcam wrote:
       | This write-up itself appears to be of amazingly high-quality.
       | What an incredible thing to give away to the world.
        
       | WORMS_EAT_WORMS wrote:
       | Can't explain why but all these E-Ink projects are so awesome and
       | attractive to me. I'm surprised I can't just buy a bunch of E-Ink
       | style gizmos from some company to decorate my home and office. My
       | wallet would be wide open to it constantly.
       | 
       | Great work and congrats on this!
        
         | jaidan wrote:
         | I'm sorry to have to let you know your wallet may empty if you
         | have not seen this already:
         | 
         | [edit: 4.7" ESP32 based epaper display with touchscreen, built
         | in battery and expansion ports]
         | 
         | https://shop.m5stack.com/products/m5paper-esp32-development-...
        
           | nisegami wrote:
           | This is incredible for something I have in mind. Going to do
           | a bit more reading, but the price and size are ideal for my
           | use case.
        
           | azeirah wrote:
           | I scoured the wave share site for all the other e-ink screens
           | and there're many cheaper ones.
           | 
           | You can get small e-ink screens (without a HAT, requires
           | adapter ~10$ and dev board which is necessary anyway) for
           | much cheaper.
           | 
           | 5.8 inch is 40$
           | 
           | 800x480, 7.5inch 50$
           | 
           | 400x300, 4.2inch E-Ink raw display, three-color 26$
           | 
           | The cheaper ones are cheap because:
           | 
           | 1) Each size comes in a low res and a high res variant, the
           | low res ones are a lot cheaper
           | 
           | 2) No HAT, so no built-in dev board for the PI. You do need
           | to somehow connect it to your dev board. An adapter with SPI
           | costs 10$, a dev board with esp8266 that has built-in adapter
           | costs ~18$. Both are officially from wave share available on
           | their site as well
           | 
           | 3) All boards below 7 inch are relatively affordable. After
           | that the price increases are huge
           | 
           | 4) Not sure why, but price difference between black/white and
           | 3-color is negligible. So feel free to pick a 5 inch tricolor
           | screen for like 40$!
        
             | antoniuschan99 wrote:
             | I'm waiting on the dev board they sell on waveshare.
             | Definitely affordable under $20.
             | 
             | For this type of project the esp32 seems like the better
             | choice than the pi zero.
             | 
             | There's also the RP2040 if you want work in the pi
             | ecosystem. Arduino and u-blox have those with wifi I think
        
             | dmitrygr wrote:
             | re: #4
             | 
             | Watch out for a few things:
             | 
             | 1. Refreshes are much slower on 3-color eInk panels than on
             | monochrome ones (eg: 20 sec vs 2)
             | 
             | 2. Partial refresh on 3-color panels is rare and quickly
             | gets messy around the edges. Partial refresh on monochrome
             | panels is a relatively simple thing to do.
             | 
             | 3. Greyscale on a 3-color eInk screen is VERY VERY VERY
             | hard! Officially it is not supported at all. By any 3-color
             | panel. I made it work [1] but even then, it is very very
             | slow (bordering on a full minute per refresh).
             | 
             | 4. Stock waveforms are rarely good. And almost no vendor
             | will give you proper temp-compensated partial update
             | waveforms. Developing your own waveforms for monochrome
             | panels is easy and simple (~day). Developing your own
             | waveforms for 3-color panels is a lot of work (~weeks +
             | more weeks once you need to support more than just "21-25
             | celsius")
             | 
             | [1] http://dmitry.gr/?r=05.Projects&proj=29.%20eInk%20Price
             | %20Ta...
        
         | jasonpeacock wrote:
         | Check out the Inkplate - a great e-ink platform for all these
         | projects and more:
         | 
         | https://inkplate.io/
        
           | x0x0 wrote:
           | Here's code that works with inkplate from a previous hn post
           | :)
           | 
           | https://rahulrav.com/blog/e_ink_dashboard.html
           | 
           | Rahul got oauth2 flows working to get google calendar access.
        
             | lawik wrote:
             | Google Calendar provides a calendar URL which might be more
             | convenient.
             | 
             | Used it in this thing:
             | https://github.com/lawik/calendar_gadget
        
         | remir wrote:
         | These projects have a pleasant "lo-fi zen" aspect that makes
         | them attractive, I think. They are simple, provide value yet
         | fade into the background without sucking your attention like
         | some other gadgets.
        
           | jbverschoor wrote:
           | It's because it's not lit. It looks natural, and unobtrusive.
           | 
           | I'd love to have this, art, and other "appliances" and slabs
           | with eink. Ex. My todo list. My email etc.
        
           | EamonnMR wrote:
           | I think they capture the feel of the black-and-white LCD
           | digital watch world from before color display android
           | everything ubiquity.
        
           | varispeed wrote:
           | Probably that's why you can't make money on it at scale that
           | you can with any addictive type of device and so it's not
           | attractive for most entrepreneurs - a lot of work to put in
           | and not enough money to even buy a Cessna.
        
             | sebcat wrote:
             | Target the high-end? There might be a demand for a device
             | with an e-ink esthetic which takes care of, I don't know,
             | planning the days of rich people? An actual need instead of
             | a manufactured want? Or maybe the lower power consumption
             | of an e-ink display can make it useful in other areas not
             | yet identified instead of consumer products?
        
             | konschubert wrote:
             | I'm trying to make it work as a product. I tend agree it's
             | a super niche market though.
             | 
             | https://www.invisible-computers.com/
        
         | oingodoingo wrote:
         | For me it's a cost issue, this is over $200... I _might_ pay
         | $100 for it, but this wouldn't be a must-buy for me until it
         | hits ~$50
        
           | politelemon wrote:
           | I've been using another eink project dashboard, which cost me
           | less as the screen is a smaller one, but it doesn't have
           | colour: https://github.com/mendhak/waveshare-epaper-display
        
           | userbinator wrote:
           | This one might be cheaper: https://github.com/zephray/NekoCal
           | 
           | ...from the same guy who did this:
           | https://news.ycombinator.com/item?id=16140284
        
         | ytdytvhxgydvhh wrote:
         | Agreed. I'm surprised the NYT won't sell me an official version
         | of this: https://news.ycombinator.com/item?id=25063726
        
         | w3p706 wrote:
         | I buy old kindles for this, ~50$ per piece. they have a linux
         | os & battery included. you get in through a serial port and a
         | password generated for your serial number. downside is that you
         | fight the kindle os in certain aspects.
         | 
         | see for example: https://github.com/Neelakurinji123/kindle-
         | weather-display
        
           | bpye wrote:
           | I wonder what it would take to build your own firmware image
           | if you were reusing for exclusive alternative use? Presumably
           | there is a Linux kernel tree somewhere and you could pull the
           | waveforms from the Amazon image?
        
             | nanomonkey wrote:
             | Check out http://fread.ink/
        
           | krzyk wrote:
           | Tried that, but when I was at the process of soldering the
           | cables to the debug ports, the "solder spots" came out of the
           | board :(
           | 
           | Now I need to press hard with a needles to make the serial
           | port work - so it is quite hard to setup - at least until I
           | install sshd there and setup wifi to make it work wirelessly.
        
           | karlkloss wrote:
           | Do you have a list of compatible kindle models, and how to
           | identify them?
        
             | w3p706 wrote:
             | I use most the paperwhite 2nd generation (212ppi
             | resolution) as this had good availability and price. but
             | the devices are quite hard to keep apart
             | 
             | the mobileread forum ist full of good information e.g.:
             | https://www.mobileread.com/forums/showthread.php?t=267541
        
         | chadd wrote:
         | i bought the 6" display from eink.com to build a small personal
         | art project - an infinite scrolling procedurally generated
         | landscape based on this project -
         | https://github.com/LingDong-/shan-shui-inf
         | 
         | A few gotchas:
         | 
         | 1. some of these eink boards are hard to procure as a consumer.
         | the vendors want you to be a company
         | 
         | 2. the driver boards are purchased separately, are definitely
         | required, and sometimes have windows software (vs easy to use
         | rasp-pi drivers)
         | 
         | 3. support is often difficult or from the OEM so english-
         | language communication can be difficult.
        
           | adiM wrote:
           | This is very interesting. Do you have a write up on the
           | procedurally generated landscape part?
        
             | blacksmith_tb wrote:
             | It was posted recently, so there's some discussion here[1]
             | 
             | 1: https://news.ycombinator.com/item?id=23469233
        
         | x0x0 wrote:
         | Here's one for $125 that I'd been planning on buying.
         | 
         | https://e-radionica.com/en/inkplate-29.html
         | 
         | The project, found on hn:
         | https://rahulrav.com/blog/e_ink_dashboard.html
        
         | leokennis wrote:
         | I think I know why these look so attractive:
         | 
         | e-ink is the perfect blend between technology (screen can
         | display whatever you want) and the analogue/physical world (it
         | looks like a piece of paper which you can put in a wooden frame
         | and interact with).
         | 
         | Another example for me is the "Buddha Machine" by FM3
         | (https://www.fm3buddhamachine.com): it's basically a box that
         | plays some ambient loops (technology) but it looks like a small
         | and unthreatening transistor radio with nice tactile buttons
         | (physical).
        
         | dirtyid wrote:
         | At the same time, disapointed reminder of the lack of the
         | progress on cheap large eink displays.
        
         | RBerenguel wrote:
         | A Raspberry Pi Zero and Pimoroni's Inky Impression are a very
         | easy cheap setup to have a cute eink gizmo. Here's a twitter
         | thread I posted with some images of it working:
         | https://twitter.com/berenguel/status/1344016064196304899 and
         | links to the screen as well.
        
         | axegon_ wrote:
         | They are neat. It's not as much in your face as a normal
         | display plus they require almost no power so you can do awesome
         | things with a SBC or an Arduino, smb32 or something else if you
         | really want to make something completely off the grid. The
         | Denali is that eink displays are still insanely expensive
         | compared to any other screen.
        
       | clash wrote:
       | This calender-thing really seems to resonate with people!
       | 
       | I built something similar but more versatile, where you can
       | either display images or feed the display with whatever
       | information you want remotely. And it runs on a battery for a
       | whole year:
       | 
       | https://framelabs.eu/en/
        
         | BozeWolf wrote:
         | Really well done!! Looks great. Although price seems
         | reasonable, it is still quite a lot of money.
         | 
         | Did you actually sell screens already? I can imagine design
         | stores want to sell this.
        
           | clash wrote:
           | I went online about a year ago. So yes, I already sold a lot
           | of devices.
        
       | iota7 wrote:
       | The e-ink displays are a bit costly. Otherwise I would get a few
       | of them and would replace all the paper calendars at home. Simply
       | a calendar, no internet, low power. Not raspberry PI based, some
       | low powered microcontroller simply displaying a paper like
       | calendar and nothing fancy.
        
       | stroz wrote:
       | Super cool concept, thanks for sharing!
        
       | konschubert wrote:
       | Hey man, this is so cool.
       | 
       | I hope it's okay to plug here: I am working towards releasing a
       | similar product for sale:
       | 
       | https://www.invisible-computers.com/
       | 
       | Unfortunately the display isn't as big as the one you chose and
       | it isn't battery powered. But I am starting to ship the first
       | units, so there is that :)
        
         | lijogdfljk wrote:
         | This looks great! Two questions if i may:
         | 
         | 1. Any plans to release some general purpose version of this?
         | Ie i'd love to buy this and hook it up to an HTML webpage i
         | generate or something. Then it's flexible to whatever i want to
         | show on my dashboard.
         | 
         | 2. Any plans for how consumers should power this hanging on a
         | wall? Since it's wired it looks like.
        
           | konschubert wrote:
           | re 1:
           | 
           | In principle that's something that I could enable eventually.
           | It's a nice idea. I'll think about it.
           | 
           | re 2: There is a standard usb plug at the far end of the
           | cable. It can be plugged into a usb charger.
        
         | IshKebab wrote:
         | That's cool. Why not battery powered though? That seems like
         | one of the biggest benefits of e-ink and also a wire coming out
         | of your calendar seems like a pretty huge drawback.
         | 
         | Love the wood bezel though; looks really nice.
        
           | konschubert wrote:
           | If I make it battery powered it needs to run on a charge for
           | a few months, otherwise it becomes a hassle. And then, it
           | must be possible to charge it easily.
           | 
           | Also, space. Right now the calendar is 7mm think and I think
           | it won't look as nice on the wall if I make it much thicker.
           | 
           | There are a lot of edge cases to consider. It's definitely on
           | my wish list but I cut it out for simplicity, for now.
        
         | chubs wrote:
         | Looks fantastic, good luck with it :)
        
         | [deleted]
        
         | WithinReason wrote:
         | Completely off topic, but you could have followed "Breakfast at
         | Tiffany's" with "Dinner with Andre"!
         | 
         | https://en.wikipedia.org/wiki/My_Dinner_with_Andre
        
           | drited wrote:
           | You weren't lying about being completely off topic.
        
       | kokey wrote:
       | I'm delighted to see the e-ink displays prices coming down, even
       | though it's coming down a bit slowly.
        
         | DantesKite wrote:
         | Imagine wallpaper sized e-ink displays.
         | 
         | would make for some amazing, decorative art.
        
       | crzysdrs wrote:
       | I wrote a similar project that generates Gameboy art from a
       | collection of roms on a Raspberry pi and displayed them on a 8
       | color E-Ink display.
       | 
       | https://github.com/crzysdrs/slate
        
       | afs27 wrote:
       | Is anyone making E-Ink displays for NFTs?
        
       | paulcarroty wrote:
       | Great idea. Will be great to have hackable audio player with big
       | battery 'cause it's hard quest to find one with good audiobooks &
       | folders support.
        
       | vesuvianvenus wrote:
       | Nice project & explanation.
       | 
       | I can see myself expanding on this (maybe even re-hashing your
       | library essentially) running:
       | 
       | 1. a Calendar,
       | 
       | 2. next to a Stock Ticker,
       | 
       | 3. next to a Financial accounts (i.e. all current asset) combined
       | with Financial goals.
       | 
       | I've been thinking about the third one for a while. E-Ink / a
       | simple, low power, monochromatic screen (similar to Amazon Kindle
       | eReader) would be a good choice.
        
         | jazzyjackson wrote:
         | I'm not 100% sure how well it would work, but pointing an old
         | kindle at a auto-refreshing web page might get the job done.
        
           | xvector wrote:
           | IIRC someone on HN once mentioned that the Kindle web browser
           | has a memory leak that will cause an OoM error/crash every
           | (1000?) refreshes. They had a workaround but I forgot what it
           | was.
        
       | nathan_f77 wrote:
       | This is awesome! I'd love to build one. But I would probably like
       | to have it plugged in, so I could update it more regularly with
       | Spotify and some info from Home Assistant. The only problem is
       | that I can't find Raspberry Pi Zeros anywhere. I tried ordering
       | one yesterday to make a little Spotify Now Playing screen, and
       | they're out of stock everywhere I looked.
        
       | ed25519FUUU wrote:
       | The first thing I always do with these E-Ink projects is to check
       | the price of the display, to see if it's come down at all since
       | the last time I checked over the last 3+ years:
       | 
       | > Waveshare 12.48" Tri-color E-Ink Display - $179.99
       | 
       | NOPE
        
         | seneca wrote:
         | The price of displays has come down. Color e-ink is new tech,
         | and as such is more expensive.
        
           | sysihyk wrote:
           | Problem is - three-pigment e-ink was a new tech 10 years ago
           | and still of luxury niche.
        
       | dmclamb wrote:
       | Why not use a raspberry pi connected to an hdtv to display this,
       | weather, news, etc.? You could make one HDMI port the "what's
       | happening" channel.
       | 
       | Plus run pinhole.
        
         | blackoil wrote:
         | This looks like a desk calendar. e-ink is low power, allowing
         | you to build a portable unit running on battery. And it has it
         | own distinctive look, which some may prefer. Though yeah, an
         | hdtv version would be lot functional.
        
         | jazzyjackson wrote:
         | It seems some of us are more averse to LCD screens than others.
         | For an always-on ambient advice, I appreciate that epaper can
         | match the lighting of the room and not draw attention to itself
         | (instead of basically being a flourescent bulb)
        
       | GTP wrote:
       | Looks great, IMO you could bring down battery usage by using an
       | ESP8266/ESP32 instead of a Raspberry PI
        
       | busymom0 wrote:
       | I would love to build something like this but the price of these
       | screens is insane :(
        
       | killjoywashere wrote:
       | You know what would be cool? An e-Ink glassboard. You need a
       | graph grid? Check. Need a smaller grid? No problem. Stylish
       | picture, sure.
        
       | SavantIdiot wrote:
       | Nice, but I can't think of less power-efficient embedded platform
       | than an RPi. Especially with something as low power as E-Ink
       | (zero power when displaying).
       | 
       | Innophase T2, Dialog DA16200, RedPines (SiLabs) RS9116, RealTek
       | Ameba... they all are super low power (like 100x less than RPi)
       | even while maintaining the 802.11 association, and come with easy
       | SDKs ready for REST HTTPS out of the box (and RTC capabilities,
       | not sure about the ameba).
        
         | miohtama wrote:
         | Can you keep RPi most of the time hibernated? Does it still
         | draw a lot of power in sleep?
        
           | kelnos wrote:
           | You don't really need to "hibernate"; shutting the entire
           | system down and booting from scratch on each update is
           | simpler and probably more reliable.
           | 
           | The problem (hibernate or not) is getting the Pi to wake up,
           | since it doesn't have a real-time clock. OP is using a RTC
           | hat to achieve this. I do wonder what kind of power
           | consumption it uses while sleeping.
        
             | SavantIdiot wrote:
             | what a colossal kludge. what you're trying to accomplish is
             | basically embedded programming 101: sleep mode + wakeup
             | timer. RTC? pff.. even any MPU on-board oscillator with no
             | crystal has good enough PPM and lower power than an RTC.
             | your solution is like hunting quail with a nuke.
        
               | KaiserPro wrote:
               | yes, but trying to generate a nice rendered image on a
               | stand-alone uProcessor is pretty hard.
               | 
               | I don't like that it takes headless chrome to render, but
               | it _works_ and fills a need for the maker.
               | 
               | I'm pretty sure they looked at the stuff they'd need to
               | write (A layout engine, a anti aliasing library, a
               | calendar parsing library, an image handling library) and
               | thought "fuck that, lets use a pi".
               | 
               | It terms of time thats weeks full time, and even then
               | might not be possible to fit on the uCPU of choice.
               | 
               | just buy a realtime hat with wake up ability, for $40
               | max, boom job done moving to making the thing look good.
               | 
               | Its not a product, its someone's hobby, leave them be.
        
               | SavantIdiot wrote:
               | > trying to generate a nice rendered image on a stand-
               | alone uProcessor is pretty hard.
               | 
               | Did you see the rendering? It is very simple, and does
               | not require PIL. There are plenty of embedded GUI
               | libraries that are specifically for this kind of
               | application (uFX, Qt). Why not learn something new?
               | 
               | I want HN to be a place where experts critique ideas, not
               | a Facebook/Instagram like-fest ego-stroke. I was
               | proposing a deeper dive to the OP so that s/he could
               | develop better skills. I wasn't mocking OP, but I was
               | mocking your bad idea because you didn't make anything,
               | you just threw out a naive suggestion.
               | 
               | Did you come here to learn or to get some karma for a
               | dopamine hit?
        
           | colonelxc wrote:
           | This very article shows how they use another product that
           | just turns on the pi on a schedule (once a day) to render the
           | updated calendar.
        
           | SavantIdiot wrote:
           | I don't think it has a hibernate mode, but it has been a
           | quite a hwile since I've downloaded the latest headless
           | server build.
           | 
           | I am currently reading 428mA at 5.0V on the power supply that
           | is driving it. It is headless and I'm not interacting with
           | it. (400mA w/ethernet unplugged). So that's 2W. I'm running
           | Buster Debian build. If you got a low power command, hit me
           | with it and I'll try it! systemctl doesn't support hibernate.
           | I don't do any low power linux programming mainly because
           | Cortex-A class processors (heck, even M7's) are already far
           | outside my power budget.
           | 
           | That is a crazy amount of power, compared to the InnoPhase T2
           | that draws ~300 MICRO Watts when connected and sleeping.
        
         | [deleted]
        
         | turtlebits wrote:
         | Sure, there are more power efficient platforms, but the project
         | uses Selenium and PIL which I'm pretty sure won't run on any of
         | those boards.
        
           | micheljansen wrote:
           | I guess you could offload the rendering to a server, but then
           | it's no longer a self-contained, standalone solution. Trade-
           | offs!
        
         | ashtonkem wrote:
         | I was going to say, I feel like an ESP32 might be a better fit
         | for this, given that it's designed for deep sleep.
        
         | mwcampbell wrote:
         | How does ESP32 compare to the products you listed?
        
           | dheera wrote:
           | I find the ESP32 _much_ easier to develop for, you don 't
           | need to install any toolchains, just plug in and drop code
           | into the virtual USB drive that shows up! I wish all
           | microcontrollers were like that these days.
        
             | BoorishBears wrote:
             | That sounds like a very specific bootloader that you're
             | using
             | 
             | ESP-IDF is still very nice though, and being CMake based
             | makes it easy to integrate outside code
             | 
             | It supports serial based uploads, which are still pretty
             | nice with the bundled serial monitor (one key combo to
             | build, upload, and restart) and OTA uploads
        
               | dheera wrote:
               | Oh sure, but it's still way better than the last time I
               | had to deal with an STM32 and install about 5 different
               | things, modify a "boards.txt" file (which there were 3
               | copies of on my system in different places and I had no
               | idea which was the real one) and then hit the program
               | button with one hand with a mouse in the air while
               | carefully timing a short of a reset trace on a PCB with
               | the other with my elbow holding down the PCB. STM32s
               | really suck. Never had to do that with an ESP32, at least
               | someone made a nice bootloader for it.
        
             | fcsp wrote:
             | How do you handle SSL? I found this very cumbersome in my
             | experiments with esp32
        
               | stavros wrote:
               | It depends on whether you want to connect to random hosts
               | or ones that you know beforehand. The latter is very
               | easy, I just hardcode the certificate fingerprint. The
               | former/dealing with CAs is harder, I've never done it.
        
               | SavantIdiot wrote:
               | I never coded on Espressif, but in other SDKs (e.g.,
               | mosquitto, mbedtls) typically this is done when you open
               | the connection at the application layer (HTTPS, MQTTS).
               | You pass in the cert bytes either as binary or PEM text
               | as a char[]. Use a CA root cert(s) from your OS/browser.
               | 
               | EDIT: grammar and typos.
        
               | konschubert wrote:
               | The high-level client in esp-idf handles ssl out of the
               | box and comes with a list of pre-installed root cas.
               | 
               | The question, of course, is: What if these CAs expire?
        
           | SavantIdiot wrote:
           | I wanted to try their Espressif ESP32 low power 802.11 part
           | back in March but it wasn't shipping yet. Their website isn't
           | clear but I'll poke around and see if it has been released
           | yet.
        
           | baybal2 wrote:
           | ESP32 is a very generic synthesized chip, not particularly
           | ULP oriented.
           | 
           | On other hand, it's the most developer friendly company out
           | there.
           | 
           | I've been unsuccessful getting any proper reaction from
           | Innophase about SDK support. Their sales seem to not even
           | understand what we are wanting from them, and keep sending us
           | "enter these AT commands through USB-TTL"
           | 
           | ESP32 is also pretty much the one, and only wireless MCU you
           | can buy on the open market, in any quantity, on a short
           | notice. Nothing else comes with the supply chain security
           | like this.
        
             | kelnos wrote:
             | > _ESP32 is a very generic synthesized chip, not
             | particularly ULP oriented._
             | 
             | Maybe not, but setting it up to sleep most of the time and
             | only boot once a day to fetch the calendar and update the
             | display should sip power pretty sparingly; I expect you'd
             | get months if not a year or more before needing to recharge
             | the battery.
        
       | reilly3000 wrote:
       | Is e-ink fundamentally more expensive to produce, or is the
       | quantity produced just not enough right now?
        
         | emsy wrote:
         | I remember reading somewhere on HN that it's a patent/monopoly
         | issue but I didn't verify.
        
       | acidburnNSA wrote:
       | Heh that's cool. It renders the calendar as HTML and then uses
       | selenium to open up headless chrome and screenshot it and then
       | send the bitmap to the eink display. Clever.
        
         | freeone3000 wrote:
         | there has to be a simpler way to draw a grid. there has to.
        
           | vanviegen wrote:
           | Sure. But this approach sounds like a sensible base to
           | quickly whip up all sorts of little projects.
        
           | pshc wrote:
           | I would volunteer LaTeX but that's also 100s of MBs/GBs of
           | dependencies to be fair. Perhaps an SVG rasterizer would
           | suffice here.
        
           | dragonwriter wrote:
           | Simpler in runtime overhead. Simpler for a developer familiar
           | with the tools used here, but less so with others? Maybe not.
           | 
           | This seems to be a hobbyist project, not a major corporate
           | effort where $100Ks were spent on tech selection.
        
             | saagarjha wrote:
             | I would not be surprised if a corporation would spend
             | $100Ks on tech selection and end up with a headless Chrome
             | too.
        
           | 41209 wrote:
           | All the complexity is handled by well known tools/libraries.
           | 
           | I can code a selenium script to capture a screenshot in my
           | sleep.
           | 
           | Often using tools your know is the best solution.
           | 
           | Your free to fork this and come up with a cleaner
           | implementation. This is probably why you need a PI Zero.
           | Smaller micro controllers can't run a full browser.
           | 
           | Most of these projects are just whatever can be hacked
           | together in a weekend.
        
           | floren wrote:
           | When all you have is a hammer...
        
           | adrianmonk wrote:
           | PostScript, maybe.
           | 
           | Instead of generating HTML from calendar data, generate PS
           | and have Ghostscript convert it to PNG.
           | 
           | I don't know PostScript, and based on the example code in the
           | wikipedia article
           | (https://en.wikipedia.org/wiki/PostScript#The_language), I
           | was able to get it to draw some text in a few minutes.
        
         | salawat wrote:
         | That is not clever. That is horrifying.
         | 
         | You have just massively bloated your set of dependencies to
         | accomplish something you could have done with a rudimentary GUI
         | toolkit.
        
           | poisonborz wrote:
           | Why tough? It works. What exactly is wasted here? 100MB for
           | Chrome binary and that few percent of CPU hike while
           | rendering the image? Is it worth wasting endless hours of
           | time researching some niche, quirky, badly documented drawing
           | library, where the hard earned end result has absolutely
           | negligible difference from a human standpoint? Machines work
           | for us, not reverse.
        
           | jazzyjackson wrote:
           | clever and horrifying are not mutually exclusive
           | 
           | he solved the problem with the tools he had, without spending
           | time learning an alternative graphics layout system. I'm
           | curious what you'd recommend as rudimentary tho, I would love
           | to see such projects on lower power devices, but if you
           | already need the Pi to talk to the ePaper, I don't see the
           | harm in burning a few cycles rendering a webpage to get the
           | result you want.
        
           | rfrankenstein wrote:
           | "Premature optimization is the root of all evil"--Donald
           | Knuth.
        
             | emsy wrote:
             | That phrase is so overused in light of massively over
             | engineered solutions that are created every day in our
             | industry . Let's face it: this project loads some data via
             | http and displays some text and primitives on a display.
             | This can easily be handled on a esp32 with room to spare.
             | But somehow we think it's normal to involve an OS, a fully
             | fledged computer and a browser to do this. Seriously, we
             | need the opposite of the Knuth quote: "When in doubt don't
             | ship a browser" or something like that.
        
           | TedDoesntTalk wrote:
           | I wonder what the reason is for this solution. He must have
           | one.
        
             | kevinsundar wrote:
             | His GitHub says this: "This might sound like a convoluted
             | way to generate the calendar, but I'm doing so mainly
             | because (i) it's easier to format the calendar exactly the
             | way I want it using HTML/CSS, and (ii) I can better delink
             | the generation of the calendar and refreshing of the eInk
             | display. In the future, I might choose to generate the
             | calendar on a separate RPi device, while using a ESP32 or
             | PiZero purely to just retrieve the image from a file host
             | and update the screen."
             | 
             | https://github.com/speedyg0nz/MagInkCal/blob/main/render/re
             | n...
             | 
             | Its easy to design something nice looking in html and css
             | and compute is cheap. Seems like a fine solution to me.
             | Maybe even better since you can push the image generation
             | somewhere else and just have the RPI update the screen with
             | an image which would save lots of power.
             | 
             | I've tried making nice interfaces with GUI toolkits and its
             | a nightmare.
        
               | KeplerBoy wrote:
               | He has a valid point, generating the image on a separate
               | device (heck, you could do that on AWS Lambda for free)
               | and only grabbing the resulting image could vastly
               | improve battery life. Then you could also switch from a
               | power hungry Pi to a simpler choice like an ESP32.
        
             | edoceo wrote:
             | Cause EInk display code works nice to just ship it an image
             | type file. So, it's gotta be rasterized before, using
             | Chromium makes that super easy - rather than hand crafting
             | PNG.
             | 
             | I personally make SVG then rasterize but this isn't that
             | terrible.
        
               | jazzyjackson wrote:
               | I was going down this route once, trying to use Inkscape
               | headless. Is there a SVG-2-bitmap tool you can recommend?
        
               | mkl wrote:
               | Another one is rsvg:
               | https://www.tutorialspoint.com/unix_commands/rsvg.htm
        
               | vbezhenar wrote:
               | Check out https://github.com/RazrFalcon/resvg
        
               | edoceo wrote:
               | Imagemagick. Does everything.
        
               | [deleted]
        
               | jazzyjackson wrote:
               | Somehow I missed that ImageMagick reads SVG, that is a
               | much shorter dependency stack than selenium! Thanks
        
             | userbinator wrote:
             | People gluing together lots of stuff to making something
             | barely-working and massively inefficient is not a new
             | phenomenon. Unfortunately, all the "maker movement" seems
             | to have done is encourage it more. Careful design,
             | knowledge and learning is being discouraged in favour of
             | superficial understanding, copy-pasting, tweaking-until-it-
             | works. They don't want to spend the time to learn the
             | basics. I was recently saddened to see someone who had
             | published code for a tiny project in Asm being asked if
             | there could be "an Arduino version".
             | 
             | Some related philosophical discussions on that here:
             | https://news.ycombinator.com/item?id=8679471
        
               | jazzyjackson wrote:
               | > Careful design, knowledge and learning is being
               | discouraged in favour of superficial understanding, copy-
               | pasting, tweaking-until-it-works.
               | 
               | This is like poo-pooing amatuer woodworking and saying
               | "people should really become an apprentice first" - no
               | one who has the education to do careful engineering is
               | being discouraged, the field of hardware and software is
               | now within reach of people who just wouldn't take on any
               | of these projects 10 years ago.
        
               | userbinator wrote:
               | _no one who has the education to do careful engineering
               | is being discouraged_
               | 
               | They are, because they think this stuff is just as good
               | --- and it clogs the search results for those who do want
               | to dig deeper. I often have to add "-Arduino -Maker" and
               | a bunch of other filters to my search results to find the
               | actually useful stuff.
        
               | jazzyjackson wrote:
               | This stuff IS good! It inspires people to task themselves
               | with projects they don't yet know how to do, and blog
               | about what error codes they received and what they did to
               | fix it.
               | 
               | Besides, how can you look down on them when you're
               | googling for answers instead of, you know, RTFM / getting
               | your engineering degree?
        
         | tejohnso wrote:
         | I use Python Imaging Library + Seaborn to push out a bar chart
         | bitmap representing some PiHole statistics to this:
         | https://thepihut.com/products/inky-impression-7-colour-epape...
        
           | acidburnNSA wrote:
           | Ah nice. Yeah I'm looking for the right display for my skymap
           | that shows the sun and moon and planets as they track across
           | the sky. It's fun to see the sun curve change with the
           | seasons. Would be way better to have on 7 color eink in the
           | living room than on my phone or laptop.
           | 
           | This one looks good. Are there any that are like 3 inches
           | bigger with borderline similar price points?
        
       | sincarne wrote:
       | This morning when I awoke, my wife had propped up her ebook
       | reader on the nightstand next to me. It looked nice. I thought:
       | how cool would it be to have a little e-ink display to which I
       | could beam a few key pieces of information?
       | 
       | Beautiful project!
        
       | Animats wrote:
       | The main problem with e-ink is finding a display that doesn't
       | cost 5x what an LCD of the same size would cost. This display was
       | $179 before it became unavailable. That's on the low end for such
       | displays bigger than phone-sized.
       | 
       | If the e-ink people ever overcome their cost problem, we'll see
       | many more products.
        
         | ghoomketu wrote:
         | Just curious but is it the lack of mass production or something
         | sinister like patents / monopoly?
        
           | Maxion wrote:
           | Patents & monopoly
        
             | rcarmo wrote:
             | Well, to be fair, large displays tend to be fragile and
             | unwieldy as well. Depends a lot on manufacturer, but in
             | essence short production runs also don't help lower the
             | price.
        
             | spuz wrote:
             | Apparently, this is not true according to an HN user
             | robinsoh who works in the industry. Check his comment
             | history more info:
             | 
             | https://news.ycombinator.com/threads?id=robinsoh
        
               | eli wrote:
               | I asked someone from Visionect (eInk maker) what was
               | driving the price for large panels and they said the same
               | thing: just not enough volume yet.
        
               | taf2 wrote:
               | At least this [1] article seems to indicate the presence
               | of patents
               | 
               | [1] https://www.businesswire.com/news/home/20171220005895
               | /en/E-I...
        
               | mannykoum wrote:
               | He doesn't seem to ever provide any evidence for his
               | claims other than a repeated "I work in the display
               | industry"..
        
               | robinsoh wrote:
               | I think you've misunderstood my comments.
               | 
               | I saw this recurring theme on HN that electrophoretic
               | panels were expensive due to patents and evil misdeeds by
               | that most evil corporation called E-Corp.
               | 
               | I thought, hey, I work in this bloody display industry
               | myself where everything is about volume, volume and more
               | volume, and I hangout with their guys at conferences and
               | events, and I've never heard such a thing as them using
               | patents to attack other industry players. Are they really
               | attacking people and hurting customers that want to use
               | their technology as alleged?
               | 
               | So I asked a simple question each time I saw that claim
               | that E Ink uses patents to attack startups or similar
               | claims. What's the evidence?
               | 
               | And guess what. Now it turns back to people like you who
               | ask what is my evidence that there's no evil misdeeds.
               | And to which I just feign shock, oh no, it must be true
               | then, since a lack of evidence for them being innocent of
               | the alllegations must mean they are guilty.
               | 
               | So we're left back at square 1. I hope people with a
               | smarter mind than mine can arrive at whatever the correct
               | conclusions are.
        
               | riobard wrote:
               | Could you please tell a bit more about the volume-side of
               | story? Somehow I feel that E-ink is at this weird point
               | on the cost/volume curve because it is a fundamentally
               | flawed display technology: monochrome or a couple of dull
               | colors at best, very slow refresh rate (with
               | ghosting/leftover on partial refresh).
               | 
               | LCD/OLED displays were also very expensive initially, but
               | because they're so much appealing universally, loads of
               | money got poured into the industry to make them better
               | and cheaper (mostly due to volume demand).
               | 
               | There's no such amount of money/interest in making E-ink
               | better and cheaper :(
        
               | robinsoh wrote:
               | Please search my comment history for what I posted about
               | electrophoresis and physics. I don't think they'll be
               | able to get past the physical limitation. To summarize,
               | you either move ink fast but end up losing bistability,
               | or move ink slow, as it is currently. Most people don't
               | realize electrophoresis has remained at about 700ms for
               | an update over the last decade. Tricks like A2 sure with
               | the Dasung, but nothing substantial.
               | 
               | As for the comment about "money/interest", see my
               | comments about why a venture capitalist would have little
               | interest in spending billions trying to create new
               | display tech and fighting hard expensive physics problems
               | when they could get higher rate of return by investing in
               | another software service or ML/AI company. That said,
               | Jeff Bezos spent hundred million or more on trying to get
               | Liquavista working, Qualcomm spent lord knows how much on
               | Mirasol. Great demos, but just couldn't get the process
               | scaled or reliable enough to commercialize. Physics is
               | hard. Physics is expensive.
        
               | evandwight wrote:
               | https://news.ycombinator.com/item?id=27831868
               | 
               | Seems to be a meaty thread if anyone else is curious.
        
               | riobard wrote:
               | Thanks a lot!
               | 
               | VC money is unlikely the source for this kinda of
               | industrial research and bumpy road to scalability.
               | 
               | LCD/OLED panels got so cheap largely due to
               | Korean/Japanese/Chinese government subsides. I doubt any
               | of them will do so for e-ink.
        
         | ppod wrote:
         | Is there any kind of projector display might would work for
         | this?
        
         | tokamak-teapot wrote:
         | I just used an old eBook reader I had lying around. It shows
         | the weather forecast.
        
           | travisporter wrote:
           | Did you repurpose the screen or use the e-reader software to
           | point to a data source?
        
       | sysihyk wrote:
       | I think Pi Nano will be seriously underworking in this setup.
        
       | GauntletWizard wrote:
       | When I was at Google I worked with the developers of the Radish
       | project [1], which was installed all over at the time. It's
       | amazing how far the state of the art has some since then. Aaron
       | told me about the memory constraints - The Radish streamed data
       | to the e-ink display's memory buffer to update, powering it on to
       | do so only briefly, while a Pi Zero is plenty enough to render
       | the whole display. We've come a very long way.
       | 
       | [1] https://developers.google.com/gdata/articles/radish
        
       | teddyh wrote:
       | * Displays one month
       | 
       | * Needs battery change more than monthly
       | 
       | I.e. it's still less work to have a paper calendar and flip a
       | page every month.
        
         | trog wrote:
         | > I.e. it's still less work to have a paper calendar and flip a
         | page every month.
         | 
         | Is there a plugin for paper calendar so it will automatically
         | sync with my Google Calendar?!
        
           | teddyh wrote:
           | No. That's a feature.
        
           | romseb wrote:
           | Install the "Handwriting" plugin on the human component. It's
           | slow, but works reasonably well.
        
         | headmelted wrote:
         | Well, I mean, it also syncs automatically with google - which
         | is kind of the whole point.
        
         | 9935c101ab17a66 wrote:
         | Do you feel this comment has contributed anything to discussion
         | around this post?
        
           | teddyh wrote:
           | Yes. The continual obliviousness which product makers (and
           | buyers) have towards battery life is very annoying. I used to
           | have a wristwatch which was the most technically advanced
           | watch I could find, and it had a touch screen and various
           | applications. Its battery consistently lasted for more than
           | two _years_ after each battery change. Eventually the touch
           | screen wore out, and I stopped using it.
           | 
           | I can't _stand_ all this modern hardware which must all be
           | charged after a few hours of use. It's a continual stress
           | factor to keep track of the charge of all your various
           | devices.
        
       | password4321 wrote:
       | I'm planning on setting up an all-in-one
       | touchscreen+computer+monitor ($300 on eBay) as a glorified family
       | to-do list manager and photo frame... any software
       | recommendations would be appreciated! (For instance, not sure how
       | well supported the touch screens are on Linux, etc.)
        
       | foolfoolz wrote:
       | i've thought about this a lot because i use a whiteboard on my
       | fridge. i would do this if it was huge like my whiteboard. like
       | 2ft by 3ft. then i can read each day at a glance. seeing the
       | whole month is huge. and writing on it means it should be a touch
       | screen
       | 
       | i find myself wanting larger displays than is for sale a lot. i
       | want an electric photo frame but not some 12in screen. i have
       | great photos i want to see them 4ft tall. this is an underserved
       | market
        
         | opencl wrote:
         | There are 31" and 42" e-ink displays available, but they cost a
         | few thousand dollars. The 42" is pretty close to 2ft by 3ft,
         | 25" x 33".
        
           | JonathanFly wrote:
           | >There are 31" and 42" e-ink displays available, but they
           | cost a few thousand dollars. The 42" is pretty close to 2ft
           | by 3ft, 25" x 33".
           | 
           | I must have 4 or 5 old Kindles in a drawer by now, somehow. I
           | wonder if you could hack together a grid of old Kindles to
           | make a giant e-ink screen?
        
             | pfranz wrote:
             | A lot of these kinds of projects render out an image and
             | send that to the display. If you did it on a server, cut up
             | the images, and had each kindle pull their image it should
             | be pretty trivial. The only immediate issue that comes to
             | mind is making sure they're relatively in sync when pulling
             | a new image if you're worried about polling too often.
        
         | hinkley wrote:
         | You definitely need to be able to make out an Information
         | Radiator from across a room. We'll probably see a tipping point
         | somewhere around a 30" screen, where you can put a large
         | summary at the top, and details farther down.
         | 
         | Is anything going on? Is it worth me crossing the room to see?
         | Should I be checking my email, other dashboards, or coworkers?
        
         | gedy wrote:
         | Might be cheaper to put a printer on top of your fridge and
         | automatically print calendar every morning into a plexiglass
         | holder :-)
        
           | pjerem wrote:
           | That could be actually nice!
        
           | dsr_ wrote:
           | Hundred dollars for the printer, probably 20 cents a day for
           | the consumables (paper, toner, electricity). The paper is
           | recyclable. At one page a day, I would guess lifetime will be
           | dominated by mechanical lubrication or degradation of
           | capacitors, dust clogs, etc.
        
             | freemint wrote:
             | Hundred dollars for the printer, I think Zou are absolutely
             | over spending here. Electricity can be saved by having
             | shutoff and turn on with a timer.
        
       | ChuckMcM wrote:
       | Seems like an ideal use for a large e-ink display, useful
       | reference information that doesn't change often. Cool.
        
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