A WiFi color eInk picture frame
spritesmods.com
spritesmods.com
I've written a Python program that anecdotally fixes the bias caused by the display for blues and greens, and dithers using an Atkinson dither. The code is based on some older Java implementation I wrote, but if you are considering a port to C this is more succinct (entry point diffuse_image()):
https://github.com/KodeMunkie/inky-impression-slideshow/blob...
The fix is to define the ink's blue as a slightly different hue than the device specifications, which tends to over emphasise it - improving it - when it comes to shades like sky blue (which the display can't achieve). So instead of (perhaps) being quantised to green, which is closer colour match for the actual real hue, more blue is shown instead. Whilst this is incorrect for photographic colour accuracy, if you don't know what the original photo looks like it appears to be correct and better than the colour that is typically chosen (green).
Sierra dithering is a nice compromise between Atkinson and basic Floyd-Steinberg.
and a bit of discussion early on about the colour issues: https://github.com/pimoroni/inky/issues/115
I'm thinking, like, "take a photo of the kids so it will show up on Grandma's frame" kind of functionality. Though, obviously, it would also be used for porn, so there's a market there, too.
Anyway, very good DIY proof of concept. I hope it's productized with some of the more recent E-Ink updates soon!
https://shop.invisible-computers.com/products/invisible-cale...
https://github.com/Invisible-Computers/image-gallery/blob/ma...
It's black-and-white, but dithering allows to show surprising detail and it brings its very own old-school aesthetic.
The API doesn't require any special knowledge about e-paper displays, it just expects an image URL in the correct resolution and will then render it to the display.
An app can be made public, such that other people who own the display can install it as well.
If you are interested in building an app, contact me at info@invisible-computers.com for a developer account :)
It's not like I am hiding it? I just didn't think it mattered in that context that this is me.
But I see your point.
[1] Full disclosure: my older brother built this service, but I don’t have an affiliation other than being a proud brother and happy customer.
5.85-inch, 600x488 pixel electronic paper with the ability to display 7 different colors
Does the dithering work well enough for a photo?
https://shop.invisible-computers.com/products/invisible-cale...
It also comes with software out of the box
It somehow makes the screen look worse!
I smile fondly and lightly jab at hackers complete lack of concern for aesthetics.
My work went with LCDs which don't match the calm wood and earth colors decor of our meeting and privacy rooms.
Not that you asked, but what I'd tweak would be a way to run the cable back into the wall.
The problem right now is that while the screens have come down in price considerably, the driver hardware remains expensive and proprietary. If you want to build something for cheap, you'll be designing the PCB from scratch (as this author did).
Enter EPDIY, which brings wide support to a variety of screens using commodity hardware. It's still under development, but it's looking really promising: https://github.com/vroland/epdiy
Would really hope some integrators can do this en masse and charge a normal fee for their trouble and provide me with a hackable EPDIY without the hassle.
https://imgur.com/a/NoTr8XX / https://hackaday.io/project/190478-hyepaper
Didnt get a chance to write an article about it. My original goal was to create a bunch of these (30x40 units) and hang them up on a wall like a large tile screen.
A controller would update this tiled wall dynamically.
Also the look of the frames were intended to disguise as regular photo frames.
Color is currently dark and so faded-looking, and even the "whites" are so muddy gray, because of the color filter technology. You can improve the number of intermediate color levels and improve the refresh rate, but the contrast and darkness is just an inherent limitation of putting color filters on top of what is otherwise just a regular monochrome e-ink display.
Achieving true CMYK color would require each capsule to contain not just two pigments (white and black) but five (white, black, cyan, magenta, yellow). Two pigments we can do because there exist two electric charges -- the white pigment is charged positive and the black is negative.
But is there any kind of theoretical technology that could toggle five sets of pigments between the top and bottom of each capsule? And indeed, do so in "subcapsules" at a small enough scale to enable perceptual color mixing, the way subcapsules do for levels of gray now?
The only thing I could imagine is if instead of using pigments inside of capsules, we used actual microscopic physical cubes, since their 6 sides would allow for 5 colors. But how you could assemble and electromagnetically control microscopic cubes 180° along two axes of movement that were suspended in some way... I can't even imagine.
I think OP is dissatisfied even with greyscale e-ink panels, though.
I love e-ink in general, it's a shame that it's still so rarely used. My fossil hybrid hr watch uses it, for example, but though the watch itself is incredible, the app is pure garbage. If that weren't the case, I'd recommend it to everyone.
I wonder if there aren't a lot more cases like that, where it seems like costumers don't like the technology, even though they mainly resent the paired implementation of the big players who thought that the technology alone was enough of a selling point, and therefore neglected the software.
There's a few gotchas here. A lot of those color e-ink displays don't work like a LCD does, where you have R/G/B subpixels per pixel and get to mix final colors out of different intensities. Instead, a "7 color display" really means each pixel can only be one of 7 pixels.
Another gotcha is that in some implementations, the screen refresh will go color by color, so for multi-color content, the refresh time is quite long (as in, you don't have a pixel flipping to blue and another flipping to red concurrently).
This is just to manage expectations -- the result is still very cool.
https://www.waveshare.com/product/displays/e-paper/7.3inch-e...
Looks nice, but the full refresh time is like 30s.
[0]https://codeberg.org/Freeyourgadget/Gadgetbridge/wiki/Fossil...
I also made a project[1] with it that generates art using a gameboy emulator and some static images and other transforms to show on the display.
Ouch, even worse than expected. The project is interesting, but I'm totally unimpressed by these numbers; I wouldn't pay a premium for a sub par display that is slow as a dead sloth. A traditional LED screen plus some tricks to save power would make a much better picture frame IMO. I would for example use a PIR/microwave sensor (they're cheap!) to detect when someone is approaching or stationing near the picture frame to bring the CPU back from sleep and turn on the display and backlight. It would never reach the same almost zero current draw of a epaper screen, but the quality gain paired with the lower cost would probably make it a viable alternative.
You'd think the company holding the patents has little incentives to push the tech forward at a faster pace, given the slow advances seen in the last decade and a half.
Laws of physics don't change. Patents aren't the problem.
The problem i ran into is that you simply cant get them in decent sizes, or with a satisfying enough resolution.
Still, as a person with no intention to DIY, I’m looking forward to a simple eink photo frame product.
Crucially, something that works out of the box and is shipping now (so: no Kickstarter, no need to write custom scripts, etc).
Personally, I'd like to see more products that repurpose old phones and tablets while scratching that "new object" itch.
Repurposing here would mean regular screen, i.e. not eink; I’m not interested in that.
https://www.stavros.io/posts/making-the-timeframe/
You can probably adapt the code to drive this display, and it displays an image from a remote server, so all you need is an HTTP server and you can easily display whatever you want.
It’s a neat idea. To be able to remotely set all tags once they’ve been properly localized.
long answer: while solar is actually the best indoor energy harvesting solution its still in nA land. This uses 56µA for the DCDC alone. that means you would need at least 1mA for maybe an hour to just keep that going without any screen updates or communications.
A windowsill setup might work but thats hardly "indoor" to me.
This lasts 1 year on 2 AA rechargeables - just swap the batteries.
If you haven't read the one where he installs Linux on a hard disk, here it is: https://spritesmods.com/?art=hddhack
I'm even pretty annoyed at spurious LEDs. I appreciate for example that Sonos speakers let you turn off their status LEDs. It just makes the ambiance calmer.
The exception is very interactive stuff like https://hackaday.io/project/190477-hyelicht where I used an LCD for the embedded touchscreen in the shelf, but powered down unless you touch it.
You'd be right about the superior picture quality, though, but as the common use would be family photos that you see in passing to make you smile and may be quick snaps, the quality of e-ink is likely to be enough when it's a quick photo of your loved ones.
Some people do not like the idea of powering a device they are not actively using. If you are not watching the piece, a «bright LED display» seems like a waste of energy.