A Digital Guestbook Is A Perfect Hacker Wedding Gift

September 22, 2020 by Lewin Day 2 Comments

With his brother’s wedding coming up, [Sebastian] needed a wedding gift. Rather than purchasing something, he elected to build a digital guestbook so guests could share their well-wishes with the happy couple.

The guestbook has a simple web-based interface, which was accessible over a domain name [Sebastian] registered with the couple’s names ahead of the event. There, users could enter text and draw a friendly message for the digital guestbook. The guestbook itself consists of an ESP32 running a e-ink display, packaged in a tidy 3D printed enclosure featuring the couple’s initials. It regularly queries the web server, and displays the messages it finds on the screen.

It’s a great use of an e-ink display, as it made reading the messages in bright daylight easy where other technologies may have faltered. [Sebastian] was also clever to install some LEDs for the night portion of the reception. We’ve featured a few wedding gifts on these pages before, including this particularly amusing sugar cube. Video after the break.

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Radon Monitor Recreates Steam Gauge With E-Ink

September 18, 2020 by Tom Nardi 11 Comments

While the full steampunk aesthetic might be a bit much for most people, those antique gauges do have a certain charm about them. Unfortunately, implementing them on a modern project can be somewhat tricky. Even if you’ve got a stock of old gauges laying around, you’ve still got to modify the scale markings and figure out how to drive them with digital electronics. While we’ve seen plenty of people do it over the years, there’s no debating it’s a lot harder than just wiring up an I2C display.

But maybe it doesn’t have to be. With his Rad-O-Matic, [Hans Jørgen Grimstad] created a pretty convincing “analog” gauge using a small e-ink panel. Of course it won’t fool anyone who gives it a close look, but at a glance, you could certainly be forgiven for thinking it was some kind of vintage indicator. Especially with the cracked and stained Fresnel lens he put in front of it.

For this project [Hans] used a LilyGo T5, which combines an ESP32 with a 2.13 inch electronic paper display. These are presumably meant to be development boards for digital signage applications, but they occasionally show up in hacker projects since they’re so easy to work with. The board pulls data from a RD200M radon sensor over a simple UART connection, and the current reading is indicated by a “needle” that moves across a horizontal scale on the display.

On its own, it wouldn’t look very vintage. In fact, quite the opposite. But [Hans] really helped sell the look on this project by designing and 3D printing a chunky enclosure and then weathering it to make it look like it’s been kicking around since the Cold War.

If you don’t feel like faking it, we’ve seen some very impressive projects based on authentic vintage gauges. As long as you don’t mind tearing up hardware that’s likely older than you are, putting in the extra effort necessary for a convincing modification can really pay off.

[Thanks to Tarjei for the tip.]

A Free Software OS For The ReMarkable E-Paper Tablet

September 6, 2020 by Tom Nardi 83 Comments

If you’re looking to rid your day to day life of dead trees, there’s a good chance you’ve already heard of the reMarkable tablet. The sleek device aims to replace the traditional notebook. To that end, remarkable was designed to mimic the feeling of writing on actual paper as closely as possible. But like so many modern gadgets, it’s unfortunately encumbered by proprietary code with a dash of vendor lock-in. Or at least, it was.

[Davis Remmel] has been hard at work porting Parabola, a completely free and open source GNU/Linux distribution, to the reMarkable. Developers will appreciate the opportunity to audit and modify the OS, but even from an end-user perspective, Parabola greatly opens up what you can do on the device. Before you were limited to a tablet UI and a select number of applications, but with this replacement OS installed, you’ll have a full-blown Linux desktop to play with.

You still won’t be watching videos or gaming on the reMarkable (though technically, you would be able to), but you could certainly use it to read and edit documents the original OS didn’t support. You could even use it for light software development. Since USB serial adapters are supported, microcontroller work isn’t out of the question either. All while reaping the considerable benefits of electronic paper.

The only downside is that the WiFi hardware is not currently supported as it requires proprietary firmware to operate. No word on whether or not [Davis] is willing to make some concession there for users who aren’t quite so strict about their software freedoms.

We’ve been waiting patiently for the electronic paper revolution to do more than replace paperbacks with Kindles, and devices like the reMarkable seem to be finally moving us in the right direction. Thankfully, projects that aim to bring free and open source software to these devices mean we won’t necessarily have to let Big Brother snoop through our files in the process.

E-Paper Display Shows Movies Very, Very Slowly

August 23, 2020 by Dan Maloney 12 Comments

How much would you enjoy a movie that took months to finish? We suppose it would very much depend on the film; the current batch of films from the Star Wars franchise are quite long enough as they are, thanks very much. But a film like Casablanca or 2001: A Space Odyssey might be a very different experience when played on this ultra-slow-motion e-paper movie player.

The idea of displaying a single frame of a movie up for hours rather than milliseconds has captivated [Tom Whitwell] since he saw [Bryan Boyer]’s take on the concept. The hardware [Tom] used is similar: a Raspberry Pi, an SD card hat with a 64 GB card for the movies, and a Waveshare e-paper display, all of which fits nicely in an IKEA picture frame.

[Tom]’s software is a bit different, though; a Python program uses FFmpeg to fetch and dither frames from a movie at a configurable rate, to customize the viewing experience a little more than the original. Showing one frame every two minutes and then skipping four frames, it has taken him more than two months to watch Psycho. He reports that the shower scene was over in a day and a half — almost as much time as it took to film — while the scene showing [Marion Crane] driving through the desert took weeks to finish. We always wondered why [Hitch] spent so much time on that scene.

With the proper films loaded, we can see this being an interesting way to really study the structure and flow of a good film. It’s also a good way to cut your teeth on e-paper displays, which we’ve seen pop up in everything from weather stations to Linux terminals.

A Desk Calendar With A Difference

July 11, 2020 by Jenny List 9 Comments

With the office computer revolution now many decades old, many of the items that once stood on a typical desk are now part of history. The typewriter, the Rolodex, and the desk calendar have all been subsumed by computers and mobile phones. This electronic desk calendar is perhaps an exception, created as a promotional device for the RT-Thread IoT OS. It features an interesting take on a perpetual calendar, with an array of days spanned by a sliding frame such that any month’s days of the week can be depicted. The days are touch buttons, and can be used to bring up the information on an e-ink display.

Behind it all is a WinnerMicro W600 WiFi-enabled system-on-chip, that runs the aforementioned RT-Thread IoT OS. This OS is a bit of a mystery, according to its Wikipedia page it’s an open-source project from China with ten years of development behind it, but this appears to be the first time we’ve seen it here at Hackaday. Anyone using it?

We like this project though, for its perpetual calendar, and for its re-imagining of a bygone desk accoutrement with an e-ink display to conserve battery. It’s not the first e-ink calendar we’ve seen, this previous one used a Raspberry Pi.

Hands On With A Batteryless E-Paper Display

June 17, 2020 by Donald Papp 64 Comments

E-paper displays are unusual in that power is only needed during a screen update. Once the display’s contents have been set, no power whatsoever is required to maintain the image. That’s pretty nifty. By making the display driver board communicate wirelessly over near-field communication (NFC) — which also provides a small amount of power — it is possible for this device to be both wireless and without any power source of its own. In a way, the technology required to do this has existed for some time, but the company Waveshare Electronics has recently made easy to use options available for sale. I ordered one of their 2.9 inch battery-less NFC displays to see how it acts.

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New Part Day: Battery-Less NFC E-Paper Display

March 22, 2020 by Erin Pinheiro 30 Comments

Waveshare, known for e-ink components aimed at hobbyists among other cool parts, has recently released a very interesting addition to their product line. This is an enclosed e-ink display which gets updated over a wireless NFC connection. By that description, nothing head-turning, but the kicker is that there is no battery inside the device at all, as it harvests the energy needed from the wireless communication itself.

Just like wireless induction charging in certain smartphones, the communication waves involved in NFC can generate a small current when passing through a coil, located on this device’s PCB. Since microcontrollers and e-ink displays consume a very small amount of current compared to other components such as a backlit LCD or OLED display, this harvested passive energy is enough to allow the display to update. And because e-paper requires no power at all to retain its image, once the connection is ended, no further battery backup is needed.

The innovation here doesn’t come from Waveshare however, as in 2013 Intel had already demoed a very similar device to promising results. There’s some more details about the project, but it never left the proof of concept stage despite being awarded two best paper awards. We wonder why it hadn’t been made into a commercial product for 5 years, but we’re glad it’s finally here for us to tinker with it.

E-paper is notorious for having very low refresh rates when compared to more conventional screens, much more so when driven in this method, but there are ways to speed them up a bit. Nevertheless, even when used as designed, they’re perfectly suited for being used in clocks which are easy on the eyes without a glaring backlight.

[Thanks Steveww for the tip!]