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E-Ink Magic Calendar that runs off a battery powered Raspberry Pi

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51–60 of 171 posts

Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi

#51
post #46

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.

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.

Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi

#54

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.

there has to be a simpler way to draw a grid. there has to.

I would volunteer LaTeX but that's also 100s of MBs/GBs of dependencies to be fair. Perhaps an SVG rasterizer would suffice here.

Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi

#55
post #46

Earlier 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.

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/ren...

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.

Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi

#56

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.

there has to be a simpler way to draw a grid. there has to.

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.

Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi

#57

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!

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

This one might be cheaper: https://github.com/zephray/NekoCal

...from the same guy who did this: https://news.ycombinator.com/item?id=16140284

Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi

#58
post #37
post #30

Earlier 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…

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

Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi

#59
post #46

Earlier 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.

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.

Re: E-Ink Magic Calendar that runs off a battery powered Raspberry Pi

#60
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.

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