Just like the clock clock of old, there’s something magical about a giant wall of smaller pieces working together to make a larger version of that thing. The E-Paper Wall 2.0 by [Aaron Christophel] is no exception as it has now upgraded from 2.9″ to 7.4″ screens.
On the 1.0 version, the bezels made it harder to make out the image. The larger screens still have bezels but the larger screen area makes it much easier to make out the image. 3D-printed clips hold the displays onto a plywood backer. We can marvel that e-ink price tags brought the price of e-ink down so that building a wall is still expensive but not eye-wateringly so. The 5×9 array likely uses a module sold on DigiKey for $47 each.
So aside from being willing to drop some money on a custom piece of art, what’s special about this? The real magic comes with the firmware and tooling that [Aaron] developed to flash custom firmware onto each of the 45 displays. A 100MHz ZBS243/SEM9110 8051-based controller lives inside each display and [Aaron] even has a Ghidra plugin to reverse-engineer the existing firmware. It only has 64kb of flash onboard, so [Aaron] devised a clever compression technique that enabled him to store complex images on the displays. A 3D-printed jig with pogo pins means flashing them doesn’t require soldering pins or headers, just drop it on and flash it with an Arduino with a helpful library [Aaron] wrote. A central station communicates with the various displays over ZigBee to send image updates.
The 8051 has a funny way of showing up in projects like this portable soldering iron or the TV Guardian. In many ways, it is a boon for us hackers as it makes it easier to reverse engineer and write new custom firmware when so many devices use the same architecture.
Almost all of modern society is built around various infrastructure, whether that’s for electricity, water and sewer, transportation, or even communication. These vast networks aren’t immune from failure though, and at least as far as communication goes, plenty will reach for a radio of some sort to communicate when Internet or phone services are lacking. It turns out that certain LoRa devices are excellent for local communication as well, and this system known as LoraType looks to create off-grid text-based communications networks wherever they might be needed.
The project is based around the ESP32 platform with an E22 LoRa module built-in to allow it to operate within its UHF bands. It also includes a USB-based battery charger for its small battery, an e-paper display module to display the text messages without consuming too much power, and a keyboard layout for quickly typing messages. The device firmware lets it be largely automated; it will seek out other devices on the local mesh network automatically and the user can immediately begin communicating with other devices on that network as soon as it connects.
There are a few other upsides of using a device like this. Since it doesn’t require any existing communications infrastructure to function, it can be used wherever there are no other easy options, such as in the wilderness, during civil unrest where the common infrastructure has been shut down, or simply for local groups which do not have access to cell networks or Internet. LoRa is a powerful tool for these use cases, and it’s even possible to network together larger base stations to extend the range of devices like these.
Over the last couple of years we’ve seen several iterations of the “slow movie player” concept, where a film is broken up into individual frames which are displayed on an e-paper display for a few minutes at a time. This turns your favorite movie into a constantly changing piece of long-term art. Unfortunately, due to the relatively high cost of e-paper panels, most of the examples we’ve seen have only been a few inches across.
Of course, technology tends to get cheaper with time, which has allowed [szantaii] to put together this beautiful 10.3-inch version. With a 1872 × 1404 Waveshare panel capable of displaying 16 shades of gray and a Raspberry Pi Zero 2 W installed in a commercially purchased frame, the final product looks very professional. It certainly wouldn’t look out of place in a well-appointed living room.
It’s not just a large display that sets this project apart. [szantaii] has done a phenomenal job documenting both the hardware and software of this project, which includes the “Slow Movie Player service” Python software he’s written. Even if you aren’t using an identical hardware setup, his MIT-licensed code will absolutely get you going in the right direction.
We especially liked the several example configurations provided, as well as the explanation of how ImageMagick’s various grayscale conversion options impact the appearance of the final image.
All in all, this is not only a beautiful and well implemented version of the slow movie player concept — but it’s also the kind of project that helps elevate the entire community thanks to its transparency. We wouldn’t be surprised to see this latest iteration inspire more folks to pick up an e-paper panel and build one of their own. Could 2023 be the year of the slow movie player? We certainly hope so.
Designing devices that can operate in remote environments on battery power is often challenging, especially if the devices need to last a long time between charges or battery swaps. Thankfully there are some things available that make these tasks a little easier, such as e-ink or e-paper displays which only use power when making changes to the display. That doesn’t solve all of the challenges of low-power devices, but [Albertas] shows us a few other tricks with this development board.
The platform is designed around an e-paper display and is meant to be used in places where something like sensor data needs to not only be collected, but also displayed. It also uses the ESP32C3 microcontroller as a platform which is well-known for its low power capabilities, and additionally has an on-board temperature and humidity sensor. With Bluetooth included as well, the tiny device can connect to plenty of wireless networks while consuming a remarkably low 34 µA in standby.
With a platform like this that can use extremely low power when not taking measurements, a battery charge can last a surprisingly long time. And, since it is based on common components, adding even a slightly larger battery would not be too difficult and could greatly extend this capability as well. But, we have seen similar builds running on nothing more than a coin cell, so doing so might only be necessary in the most extreme of situations.
The original Polaroid cameras were a huge hit not just for their instant delivery, but for the convenient size of the permanent images they delivered. It’s something that digital cameras haven’t been able to replicate, which drew [Cameron] to produce a modern alternative. In the place of the chemical film of the original, it uses a removable e-paper display in a frame. The image is stored in the pixels of the e-paper, which can be kept as a digital version of the photograph until reattached and replaced with another freshly taken picture.
At its heart is an ESP32 with a camera, and the “film” is a Waveshare NFC e-paper module. The device is 3D printed, and manages a very creditable early-1970s aesthetic redolent of the more upmarket Polaroids of the day. Using it is as simple as pressing the button and deciding whether you like what’s on the screen. You can see it in action in the video below the break.
We like his project for its aesthetics, as well as for the very idea of using e-paper as a medium. There’s also something to be said for not having to put a Polaroid print in a clip under your armpit while it develops. Meanwhile if you do hanker for the real thing, it’s a subject we’ve looked at in the past.
The three interlocking frames were printed out of “Walnut Wood” HTPLA from ProtoPasta, and hold a pair of 5.79 inch red/black/white displays along with a single 7.3 inch red/yellow/black/white panel from Waveshare. There are e-paper panels out there with more colors available if you wanted to go that route, but judging by the striking images [Zach] has posted, the relatively limited color palettes available on these displays doesn’t seem to be a hindrance.
To create the images themselves, [Zach] wrote a script that would generate endless customized portraits using Stable Diffusion v1.4, and then manually selected the best to get copied over to a 32 GB micro SD card. The side images were generated on the dreamstudio.ai website, and also dumped on the card.
Having a child is a major milestone in a person’s life, and there’s a long list of things to get done before that little bundle of joy kicks and screams its way into the world. What better way to make sure you’ve still got time to paint the nursery and assemble the crib than to have an automated loading screen that shows just how far along the organic 3D printing process is?