[HN Gopher] E-Ink Magic Calendar that runs off a battery powered...
___________________________________________________________________
 
E-Ink Magic Calendar that runs off a battery powered Raspberry Pi
 
Author : edward
Score  : 123 points
Date   : 2021-10-03 20:59 UTC (2 hours ago)
 
web link (github.com)
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-...
 
    | 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$!
 
  | 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.
 
  | 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
 
  | ytdytvhxgydvhh wrote:
  | Agreed. I'm surprised the NYT won't sell me an official version
  | of this: https://news.ycombinator.com/item?id=25063726
 
  | 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
 
  | 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.
 
| kokey wrote:
| I'm delighted to see the e-ink displays prices coming down, even
| though it's coming down a bit slowly.
 
| 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
 
| 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.
 
| busymom0 wrote:
| I would love to build something like this but the price of these
| screens is insane :(
 
| 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?
 
    | 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.
 
  | 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.
 
  | ashtonkem wrote:
  | I was going to say, I feel like an ESP32 might be a better fit
  | for this.
 
  | 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
 
      | 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.
 
    | 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.
 
| 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.
 
    | floren wrote:
    | When all you have is a hammer...
 
| 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".
 
  | 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 :-)
 
    | 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.
 
___________________________________________________________________
(page generated 2021-10-03 23:00 UTC)