Open Hardware E-Ink Display Just Needs An Idea

May 12, 2019 by Tom Nardi 25 Comments

Its taken awhile, but thanks to devices like the Amazon Kindle, the cost of e-ink displays are finally at the point where mere mortals such as us can actually start using them in our projects. Now we’ve just got to figure out how to utilize them properly. Sure you can just hook up an e-ink display to a Raspberry Pi to get started, but to truly realize the potential of the technology, you need hardware designed with it in mind.

To that end, [Mahesh Venkitachalam] has created Papyr, an open hardware wireless display built with the energy efficiency of e-ink in mind. This means not only offering support for low-energy communication protocols like BLE and Zigbee, but keeping the firmware as concise as possible. According to the documentation, the end result is that Papyr only draws 22 uA in its idle state.

So what do you do with this energy-sipping Bluetooth e-ink gadget? Well, that part is up to you. The obvious application is signage, but unless you’re operating a particularly well organized hackerspace, you probably don’t need wireless dynamic labels on your part bins (though please let us know if you actually do). More likely, you’d use Papyr as a general purpose display, showing sensor data or the status of your 3D printer.

The 1.54 inch 200×200 resolution e-ink panel is capable of showing red in addition to the standard grayscale, and the whole thing is powered by a Nordic nRF52840 SoC. Everything’s provided for you to build your own, but if you’d rather jump right in and get experimenting, you can buy the assembled version for $39 USD on Tindie.

E-Ink Price Tags Fall Off Store Shelves Onto Your Workbench

February 25, 2019 by Jenny List 38 Comments

There’s always a magic moment for our community in the lifecycle of any piece of technology: the point at which it first becomes available for pennies on the surplus market. Something which could previously be had only at a price is rendered down to mere pennies, and we are free to hack to our heart’s content.

Such a moment came for [Aaron Christophel] when he bought a quantity of used e-ink price tags (German, Google Translate link) that had formerly graced the shelves of a supermarket. A pile of readily hackable e-ink displays lay before him, so he set to work.

Cracking them open he found the display itself as well as a PCB with its own microcontroller, but he soon identified it as compatible with a WaveShare module for which he had data. Since its interface was thus identified as SPI he could desolder the unknown CPU and break out the pins for an Arduino or other board. The display itself turned out to be a custom model with a few quirks for price tags, it had a black border that could be enabled, and for some reason it appeared as a two-colour red-and-black model in which its black pixels responded as though they were the red channel. He has a quick overview video that we’ve placed below the break.

These displays have started appearing in our community, not least in electronic conference badges. This source of cheap components from the surplus market makes them ever more accessible, and we look forward to the projects that will come from them.

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Get Organized With This Raspberry Pi E-Ink Calendar

February 11, 2019 by Tom Nardi 15 Comments

Like many hackers, we love e-ink. There’s something mesmerizing and decidedly futuristic about the way the images shift around and reconstitute themselves. Like something from Harry Potter, but that you can buy on Alibaba instead of from a shop in Diagon Alley. But as anyone who’s used the technology can tell you, the low refresh rate of an e-ink screen limits its potential applications. It works great for reading books, but beyond that its struggled to find its niche in a world of cheap LCDs.

But [Zonglin Li] has recently wrapped up a project which shows that e-ink has at least one more use case: personal calendars. You can get way with only updating the screen once a day so the refresh rate won’t matter, and the rest of the time it’s going to be static anyway so you might as well enjoy the energy savings of leaving the screen off. With a Raspberry Pi behind the scenes pulling data from the Internet, it can populate the calendar with everything from your personal schedule to when your favorite podcast drops.

In practice, [Zonglin] is actually updating the display every hour as he’s included the current weather conditions on the top left of the screen, but even still, this is a perfect application for the very unique properties of e-ink displays. The display is a 7.5 inch 640×384 model from Waveshare that retails for about $50 USD, so between the display, the Raspberry Pi, and something to put it all in (here, a picture frame) this is a pretty cheap build compared to some of the large format e-ink displays out there.

The software side is written in Python 3, and [Zonglin] has documented how others can easily plug in their own information so it can pull schedule data from Google Calendar and local conditions from Open Weather Map. The MIT licensed source code is also very well organized and commented, so this could serve as an excellent base if you’re looking to create a more comprehensive e-ink home information display.

If this seems a little too pedestrian for your tastes, you could always put together an e-ink movie player, a surprisingly functional Linux terminal, or a very slick ESP8266-based name tag. If you’ve got the better part of $1K USD and don’t know what to do with it, you could even get an e-ink license plate.

Digital License Plates Are Here, But Do We Need Them?

February 1, 2019 by Tom Nardi 81 Comments

It’s a story as old as time: you need to swap between your custom license plates, but you can’t find a screwdriver and you’re already running late for a big meeting at the Business Factory. You called AAA to see if they could come out and do it for you, but as luck would have it something must be wrong with your phone because the line was disconnected as soon as you explained the situation. As if life in the First World couldn’t get any more difficult.

Luckily, a company called Reviver Auto has come up with a thoroughly modern solution to this age old problem. Assuming you live in Arizona, California, and Michigan and are willing to pay $800 USD (plus a small monthly service fee), you can join the Rplate revolution! Less a license plate and more of a “cool-looking, multi-functional digital display and connected vehicle platform”, the Rplate will ensure you never again find yourself stuck on the side of the road with an unfashionable license plate.

What’s that? You’ve had the same license plate for years, possibly decades, and have never given it much thought? Well, in that case the Rplate might be sort of a tough sell. Did we mention that someday you might be able to display the current weather on it while your car is parked? Of course, if you can see the license plate you’re already outside, so…

This all might sound like an out of season April Fool’s joke, but as far as I can tell from reading the Reviver Auto site and watching their promotional videos, this is essentially the value proposition of their line of Rplate digital license plates. There are some admittedly interesting potential extensions of the technology if they can convince other companies and systems to plug into their ecosystem, but given the cost of the Rplate and the few states in which it’s currently legal to use, that seems far from a given at this point.

But of course we’re fans of weird and wonderful technology here at Hackaday, so we should give this device a fair shake. On the surface it might seem to be a solution looking for a problem, but that’s often said of technology ahead of its time. So what exactly is the Rplate, how does it work, and where does it go from here?

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The Very Slow Movie Player Does It With E-Ink

December 30, 2018 by Richard Baguley 18 Comments

Most displays are looking to play things faster. We’ve got movies at 60 frames per second, and gaming displays that run at 144 fps. But what about moving in the other direction? [Bryan Boyer] wanted to try this out, so he built the VSMP, or Very Slow Movie Player. It’s a neat device that plays back a movie at about 24 fph (frames per hour) on an e-ink display to demonstrate something that [Bryan] calls Slow Seeing, which, he says “helps you see yourself against the smear of time.” A traditional epic-length movie is now going to run you greater than 8,000 hours of viewing.

Artistic considerations aside, it’s an interesting device from a technical point of view. [Bryan] built it from a 7.4-inch e-ink display from Pervasive Displays. The controller is connected to a Raspberry Pi Zero, which is running a Python script to convert a frame of the movie file into a dithered file, then send it to the display. Because the Pi Zero isn’t a very fast computer, this takes some time, and thus the slow speed of the VSMP. Originally, [Bryan] had set it up to run as fast as the system could manage, which was about 25 seconds per frame, or about 2 frames per minute. He decided to slow it down a bit further to the more attractive multiple of 24 frames per hour to contrast with the 24 frames per second of the original movie. He did this by using a CRON job that kicks of the conversion script once every 2.5 minutes and increments the frame counter. All of this is topped off with a nice 3D-printed case that has a lovely interference pattern to make a rather neat and intriguing project.

Perhaps the best part of this is see a time-lapse of the VSMP — life moves quickly around it while 2001: A Space Odyssey plays at normal speed.

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Using E-Paper Displays For An Electronic Etch A Sketch

November 9, 2018 by Al Williams 12 Comments

Electronic things are often most successful when they duplicate some non-electronic thing. Most screens, then, are poor replacements for paper. Except, of course, for E-paper. These displays have high contrast even in sunlight and they hold their image even with no power. When [smbakeryt] was looking at his daughter’s Etch-a-Sketch, he decided duplicating its operation would be a great way to learn about these paper-like displays.

You can see a video of his results and his findings below. He bought several displays and shows them all, including some three-color units which add a single spot color. The one thing you’ll notice is the displays are slow which is probably why they haven’t taken over the world.

The displays connect to a Raspberry Pi and many of the displays are meant to mount directly to a Pi. The largest display is nearly six inches and some of the smaller displays are even flexible. It appears the three color displays were much slower than the ones that use two colors. To combat the slow update speeds, some of the displays can support partial refresh.

The drawing toy uses optical encoders connected to the Raspberry Pi. The Python code is available. Even if you don’t want to duplicate the toy, the comparison of the displays is worth watching. We were really hoping he’d included an accelerometer to erase it by shaking, but you’ll have to add that feature yourself. By the way, in the video, he mentions the real Etch-a-Sketch might work with magnets. It doesn’t. It is an aluminum powder that sticks to the plastic until a stylus rubs it off.

We’ve seen these displays many times before, of course. If you are patient enough, you can even use them as Linux displays.

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Corporate Badgelife: Oracle’s Code Card

October 31, 2018 by Tom Nardi 30 Comments

We tend to think of elaborate electronic conference badges as something limited to the hacker scene, but it looks like the badgelife movement is starting to hit the big time. Now even the “big boys” are getting into the act, and pretty soon you won’t be able to go to a stuffy professional conference without seeing a sea of RGB LEDs firing off. We’ll let the good readers of Hackaday determine if this means it’s officially post-cool or not.

[Noel Portugal] writes in to tell us about how he created the “Code Card” during his tenure with the Oracle Groundbreakers Team. Featuring an ESP8266 and an e-ink screen, the Code Card serves not only as swanky way of identifying yourself, but as a real-world demonstration of physical devices pulling content from Oracle’s Cloud. Gotta keep those corporate overlords happy.

The Code Card is a fairly simple piece of hardware as far as badges go these days, but then the goal was never to be flashy. It does feature dual four-pin Grove System connectors on the backside though, so you can plug in additional sensors and gadgets for the customary badge hacking sessions.

To maximize runtime on the rechargeable coin cell battery, the Code Card only turns on the ESP after the user has pressed one of the buttons on the front. Once the ESP has finished performing whatever task the user requested, its powered back off completely rather than put into standby. Combined with the e-ink screen, power consumption while the device isn’t actively updating the display or pulling down new content is negligible.

[Noel] really went all-out on the software side, going as far as developing a web application which let conference attendees configure their Code Cards from their smartphones. Different functions could be assigned to short and long presses on the badge’s two buttons, and users could even select icons for the various functions from a list of images included in the firmware. A feature where attendees could upload their own images didn’t make the cut, but that surely won’t stop people from hacking around in the published Arduino source code and figuring out how to do it manually.

If you think the Code Card looks a bit familiar, it’s perhaps because it was designed in conjunction with Squarofumi, creators of the Badgy. So even if you aren’t hitting up any of Oracle’s upcoming conferences, you’re not completely out of luck if you want an e-ink badge to play with.