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.
E-Ink Magic Calendar that runs off a battery powered Raspberry Pi
61–70 of 171 posts
Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi
#62Earlier quoted context omitted.
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-...
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$ 800×480, 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…
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...
Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi
#63Earlier quoted context omitted.
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.
I wonder what the reason is for this solution. He must have one.
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
Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi
#64Heh 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.
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.
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.
Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi
#65Earlier quoted context omitted.
I wonder what the reason is for this solution. He must have one.
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 saddene…
> 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.
Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi
#66Earlier quoted context omitted.
I wonder what the reason is for this solution. He must have one.
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.
I was going down this route once, trying to use Inkscape headless. Is there a SVG-2-bitmap tool you can recommend?
Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi
#67Nice 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.
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.
Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi
#68I'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.)
Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi
#69Nice 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.
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.
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.
Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi
#70Why 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.
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)