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.
Continue reading “A Digital Guestbook Is A Perfect Hacker Wedding Gift”
It’s a shame that so many cool things happen in the night sky, but we can’t see them because of clouds or light pollution. If you missed seeing the comet NEOWISE or this summer’s Perseid meteor showers, there’s not a lot to be done but look at other people’s pictures. But if it’s the Moon and its phases you keep missing out on, that information can be acquired and visualized fairly easily.
This project includes a bunch of firsts for [Jacob Tarr], like designing a custom PCB and utilizing a three-color E-ink screen to show the Moon in its current phase along with the date and time.
[Jacob]’s moon phase viewer runs on an ItsyBitsy M4 Express, which holds data pulled from NASA ahead of time to save battery. Every morning, the board dishes out the daily info on a schedule kept by a real-time clock module.
We particularly like the minimalist case design, especially the little shelf that holds the lithium-ion cell. This is just the beginning, and [Jacob] plans to add more detail for anyone who wants one for themselves.
If you want something more Moon-shaped, here’s a printed version that gets brighter in time with the real thing. Or you could just make a giant light-up full moon like Hackaday super alumnus [Caleb Kraft].
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!]
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.
Continue reading “E-Ink Price Tags Fall Off Store Shelves Onto Your Workbench”