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Comment by acidburnNSA | Hacker News Reader

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.

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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...

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?

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.

I would not be surprised if a corporation would spend $100Ks on tech selection and end up with a headless Chrome too.

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.

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.

When all you have is a hammer...

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

Sure. But this approach sounds like a sensible base to quickly whip up all sorts of little projects.

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.

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.

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.

“Premature optimization is the root of all evil”—Donald Knuth.

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.

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.

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.

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?

Imagemagick. Does everything.

Somehow I missed that ImageMagick reads SVG, that is a much shorter dependency stack than selenium! Thanks

Another one is rsvg: https://www.tutorialspoint.com/unix_commands/rsvg.htm

Check out https://github.com/RazrFalcon/resvg

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

> 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.

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.

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?

and blog about what error codes they received and what they did to fix it

That is often more than useless to everyone not exactly in that one person's situation.

Besides, how can you look down on them when you’re googling for answers instead of, you know, RTFM / getting your engineering degree?

When trying to find TFM is itself a problem... I'm definitely not one to want to be "censoring misinformation" unlike a lot of others, but the blind leading the blind is certainly happening a lot and it doesn't help anyone.

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