I worked on a number of digital photo frames, including on ones like that.
E-ink is not the most suitable thing for it in its current form.
First, large size EPD cost an arm, and a leg, and custom one costs even more.
Second, there are no 8 bit EPD controllers as of now a mortal can buy, which means grays look very bad.
Third, there are inherent physical limitations which make increasing gray resolution of EPDs quite hard. The precision you want, the slower would the refresh rate be.
If somebody is old enough to remember, (saying this as a 30 years old is indeed amusing to myself) the last active matrix monochrome LCDs had 8 bit, and more of gray resolution, but they are all discontinued now, or cost an arm, and a leg as "medical imaging" specialty.
At 150 dpi the image depth is not a problem. Here is the 4-bit image of the 1929 Bentley as displayed on the frame for reference: https://www.instagram.com/p/CItoGRLh52n/
On the device you only notice if you get extremely close.
(Disclaimer: I think this display is awesome -- can't allocate the funds for it right now, but will be keeping an eye on it going forward.)
The image is "contrasty", showing lots of hard transitions from bright to dark. With displays of low bit-depth, the hard thing to do is smooth gradients of tonality.
Second, there are no 8 bit EPD controllers as of now a mortal can buy, which means grays look very bad.
Third, there are inherent physical limitations which make increasing gray resolution of EPDs quite hard. The precision you want, the slower would the refresh rate be.
For a digital picture frame, refresh rate isn't that important. In fact, a "gradual shading" on refresh might even make for a neat transition effect[1].
IMHO it's just the "cartel" (they like to keep the details of driving their displays confidential) of EPD controller companies who haven't produced controllers with more than 16 levels of grayscale, but the material is fundamentally analog and here is proof that if you drive the display directly, you can get at least 32 levels of grayscale if not more:
With a bit of careful calibration, I believe far finer grayscale is possible.
[1] Although EPDs have been around for a long time now, I have yet to see the demoscene do anything with them --- a directly driven display naturally allows for a lot of effects due to it effectively being an "analog write-only memory".
On the second point, my experience comes from a Kobo Glo HD eReader, but the rendition of photographs is very good - cliché, but its like a printed page. Line art obviously works best because its bold and high contrast, but colour digital art and black and white photographs all display very well in my opinion.
The difficult bit is making it not look like a screen. Even the fancy Sony "the frame" (which are supposed to do clever matching to room brightness etc) TVs don't get that quite right, and only do it in some special mode...
The costs in electricity bill is gonna be big compared to e-ink. Refresh rate of static picture can be terrible, OK for this use case. There's also color e-ink devices, though not many, and the colors were IMO too pastel-ish.
Although backlight of a second hand TV might also be dying, I agree say Chromecast on TV gives a nice effect. My oldest kid gets impressed, FWIW.
If you can plug it into a wall, have a Raspberry Pi 4 series driving a 4K TV of the size of your choice.
The cheapest one I see on Amazon right now is a 40" 4K HDR from Vizio, with quite a small bezel - $240. Hang it on a wall and paint the bezel white, or make a nice wood frame for it.
5W for the Pi, 60W for the screen is about 550kWh per year, or around 200kg of CO2 (give or take your local energy mix). That's about 10% of an average Indian's emissions.
I agree that the poor contrast etc of EPDs hurt them, including in this area. I'm questioning what you think are better alternatives for this use; I don't think there are any that don't have flaws worth weighing.
I thought Amazon held them, my bad. I was interested in this space around the time of the Kindle Fire release. It seemed to me like they just didn't want to chase a form factor that couldn't sell 90% of their media. So maybe there is a way, but no will.
Thanks. That's pretty awesome. Looks like they did run into the issue of no data sheets and had to hack around to get/make the driver for updating the screen, which is what I expected. Hope they keep improving it! And at $15 that's a great price. I paid more for a 2.5"x1" display but I needed the friendly pi integration.
Thanks for responding. I was quite interested really in the concept that the title seemed to indicate, I was expecting a blog post at least, and surely something along those likes would do better on HN
No, true minimalism would be doing without this needless frame.
I actually think it's cool though I'd want one much much MUCH larger. My comment is mostly about the smug comment at the end. It's not minimalism to clutter your life with a superfluous gadget
I am building something like this, but the pandemic has prevented me from collaborating with my frame maker. The e-ink panel I have has a fairly fragile ribbon cable we are trying to hide inside the frame with some clever cuts. I am not sure how the panels for Kindles allow them to have such small margins.
The biggest problem I have is fitting a battery into the frame -- I was trying to find a low profile USB battery pack that could output 5V for RPi Zero. Maybe I should wire up some battery cells directly to evenly distribute the weight?
I had this idea years ago! I'm glad someone finally did it. One thought. From a philosophical point of view, I would want this to be something that "lasts forever". So it would be nice if it were solar powered and ran off of an SD card rather than being web-based. Just an opinion from an HN extremist - take it in context. Still, it's scratching an itch for me. Your website is down so I didn't see how much it costs but I'll check back in a bit.
Thanks for your input. I was thinking about a way to have it powered by ambient energy. It is hard to integrate the solar cell in a way that it does not distract from the actual picture, though.
Could try extracting energy from radio waves with a wire antenna around the frame (it's not a lot, but for charging some sort of battery it could work)
I've setup multiple "Photo frames" with Raspberry Pi zero connected with screen of different size, which fetches the photos stored on local hard drive hosted with Lomorage running on Raspberry Pi 4. Check it out, https://www.reddit.com/r/raspberry_pi/comments/fj3li8/digtal...
I am working on providing feeds with "Picture of the day" for the device. I agree that that service should run hardened software to prevent your scenario from happening.
If you run the device in local mode though, WiFi is never enabled.
Hey! I’ve wanted to make (or buy) one of these for years! (A battery-powered eink picture frame with no power cord.) I hope you get your site back up soon! And eventually branch into color eink and larger (wall-hangable) sizes!
If you can get an old Kobo eReader it actually had software built in for an image based slideshow that was accessible. It's a good but small eink screen.
I had a few set up for it. But the dream would have been to have them networked and remotely accessible to update the content. I believe they were running on Linux so it would probably be doable.
I bought my first arduino because I wanted information radiators I could just hang on an office wall, without a network cable for sure. And without a power cord if at all possible. I never got far. I could probably build now what I wanted then, but I’m not sure anyone would find it compelling, least of all me.
I actually built one myself, but used raspberry pi so it needs usb cable for power. It works well but contrast on the display is not that good for photos. Would work well for text or like smart home panel.
Nice work. Getting rid of the cable was actually the most important feature for me. It is almost impossible to spot that this is actually an electronic device if one doesn't notice the small button at the bottom.
For me, I found that the display I'm using works reasonably well for photos, but you need to slightly boost the contrast of the image before updating the display, to compensate for the darkness of the display. If you're using PIL in python, this is just something like "image = PIL.ImageEnhance.Contrast(image).enhance(1.3)"
I do that immediately before dithering into 16-greys, and get entirely acceptable photo displays that way.
I am using simple shell script and imagemagick to convert folder full of images and then randomly rotate the pictures. I tried playing with contrast but after dithering and that did not produce good results.
The device ships with sample code included. So if you want to try your own use case, this is possible. I will also add it to https://github.com/framelabs-eu shortly.
This is an advertisement linking to a broken storefront in case anyone was wondering.
Maybe the creator can share more about the design of this device (ex/ what embedded device you're using (ESP32?), is an ASIC driving the display, epaper supplier, etc.)?
Have you considered using E INKs Kaleido coloured epaper?
I found the image server, in the spirit of using your device for fun and interesting things (say nothing of privacy).. Why would you need the online converter, if you selfhost the image-server?
(potential customer here, but wanna use it not for pictures but for "daily status")
I would like if you could just set a url pattern that sent over some device specific id and the resolution as parameters and it would poll it on some configurable frequency.
I love this and have wanted it forever. I was actually ready to buy but I have no use for the 9.7” size in regards to an actual art display. It’s just way to small for anything but family photos, which I like to be in color and on my desk.
Nice idea and cool how you made it into a product. Could you provide us with a tad more technical specs? Since the website is down and it isn't archived yet would be good to see some of that tech specs here.
It is a 9.7" screen with 1200x825 pixels, which make it 150 ppi. It has WiFi built-in to load pictures from remote sources and also features a small local storage for up to 100 pictures. The battery should last for around 7000 changes of the picture. The frequency of picture changes can be adjusted and also defines how many years it will take for the battery to run out.
Pictures are dithered and contrast/brightness can be adjusted during upload, which can be done via the device's WiFi hotspot. Or you can configure it to connect to your local WiFi for easier access.
Yeah especially since it's Wordpress with Woocommerce so enabling caching isn't super straightforward, although it looks like there hasn't even been any attempt made.
E-ink is not the most suitable thing for it in its current form.
First, large size EPD cost an arm, and a leg, and custom one costs even more.
Second, there are no 8 bit EPD controllers as of now a mortal can buy, which means grays look very bad.
Third, there are inherent physical limitations which make increasing gray resolution of EPDs quite hard. The precision you want, the slower would the refresh rate be.
If somebody is old enough to remember, (saying this as a 30 years old is indeed amusing to myself) the last active matrix monochrome LCDs had 8 bit, and more of gray resolution, but they are all discontinued now, or cost an arm, and a leg as "medical imaging" specialty.