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38 Articles

A wearable circuit sculpture in the form of a smart bracelet that shows daily to-dos.

Wearable Circuit Sculpture Is One Smart Bracelet

April 17, 2026 by 2 Comments

Well, this might just be a Hackaday first. Certainly not the circuit sculpture part, nor the wearable aspect, but the glorious combination of the two. Behold [CMoz]’s Fashionably on Task: a Smart Bracelet for Forgetfulness. The name may be long, but the intent is concise: to showcase your top five must-dos for the day.

This lovely bracelet uses a tri-color e-paper display, and it’s WiFi enabled in order to receive input from the corresponding phone app. Although the cute pink ESP32-C3 is programmed in PlatformIO, the code will work with the Arduino IDE as well.

To get down to business, just power on the bracelet. If it can’t connect to the network you’ve hard-coded, it will broadcast it’s own access point. Connect with your phone to the custom web page, and Bob’s your uncle. From here, you can enter the tasks, change the colors around, mark tasks as complete, and remove tasks or reset recurring reminders.

The nifty part is that e-paper screen, since it will of course continue to display your list once powered down. Here’s the full code. Then you can deep-dive into the graph theory of circuit sculptures.

Mimisbrunnur

Calculator Case To Scratch-Built Pocket E-Reader

March 11, 2026 by 7 Comments

E-readers are an awesome creation allowing you to display digital information in a way that requires little battery life. While there’s plenty of very impressive models to chose from on the commercial market, it’s also possible to build one yourself — which is exactly what [kaos-69] did in his Mimisbrunnur project, creating a truly unique e-reader from scratch.

While looking through old junk at home, [kaos-69] came across a case that held a calculator and pen at one point in the distant past. The pen was gone and the calculator no longer functioned but the case held promise. He removed the calculator and got some parts on order. For the e-paper display he went with a 5.83-inch unit that just fit inside the spring-loaded case. The Mimisbrunnur is powered by a 2000 mAh LiPo battery, with a micro SD card reader for storing what will be displayed. The brains come from an RP2040 microcontroller on an Adafruit Feather breakout board, which worked out great as it already takes care of battery management and the 24-pin interface for the e-paper display.

There are also eight buttons that live below the display for user interface, and even some LEDs to aid in reading in the dark. The depth of the case allowed all this to be connected with the use of a perfboard and some risers to set the screen forward, allowing the battery to live behind it. Using the Mimisbrunnur is pretty straightforward with the eight buttons sitting below icons on the screen giving you clear guidance on how to turn the page, add a bookmark, or browse the SD card for another file to open.

We’ve seen some impressive DIY e-readers over the years, such as the dual-screen Diptyx and the Open Book. But this project is an excellent reminder that a device doesn’t have to be complex to get the job done.

DIY E-Reader Folds Open Like A Book

December 24, 2025 by 36 Comments

There are plenty of lovely e-readers out on the market that come with an nice big e-paper display. There aren’t nearly as many that come with two. [Martin den Hoed] developed the Diptyx e-reader with such a design in order to better replicate the paper books of old. 

The build is based around the ESP32-S3, a powerful microcontroller which comes with the benefit of having WiFi connectivity baked in. It’s hooked up to a pair of 648×480 e-paper displays, which are installed in a fold-open housing to create the impression that one is reading a traditional book. The displays themselves are driven with custom look-up tables to allow for low-latency updates when turning pages. The firmware of the device is inspired by the epub reader from [Atomic14], and can handle different fonts and line spacing without issue. Power is from a pair of 1,500 mAh lithium-polymer cells, which should keep the device running for a good long time, and they can be charged over USB-C like any  modern gadget.

You can follow along with the project on the official website, or check it out on Crowd Supply if you’re so inclined. The project is intended to be open source, with files to be released once the design is finalized for an initial production run.

We’ve seen some great DIY e-reader builds over the years, and we’re loving the development we’re seeing in the writer deck space, too. If you’re whipping up something fun in this vein, be sure to let us know on the tipsline!

Get Statistical About Your Pet With This Cat Tracking Dashboard

December 13, 2025 by 3 Comments

Cats can be wonderful companions, but they can also be aloof and boring to hang out with. If you want to get a little more out of the relationship, consider obsessively tracking your cat’s basic statistics with this display from [Matthew Sylvester].

The build is based around the Seeedstudio ReTerminal E1001/E1002 devices—basically an e-paper display with a programmable ESP32-S3 built right in. It’s upon this display that you will see all kinds of feline statistics being logged and graphed. The data itself comes from smart litterboxes, with [Matthew] figuring out how to grab data on weight and litterbox usage via APIs. In particular, he’s got the system working with PetKit gear as well as the Whisker Litter Robot 4. His dashboard can separately track data for four cats and merely needs the right account details to start pulling in data from the relevant cat cloud service.

For [Matthew], the build wasn’t just a bit of fun—it also proved very useful. When one of his cats had a medical issue recently, he was quickly able to pick up that something was wrong and seek the help required. That’s a pretty great result for any homebrew project. It’s unrelated, too, but Gnocci is a great name for a cat, so hats off for that one.

We’ve featured some other fun cat-tracking projects over the years, too. If you’re whipping up your own neat hardware to commune with, entertain, or otherwise interact with your cat, don’t hesitate to let us know on the tipsline.

ESP32 Dashboard Is A Great Way To Stay Informed

June 18, 2025 by 3 Comments

The original ESP32 may be a little long in the tooth by now, but it remains a potent tool for connected devices. We were drawn to [Max Pflaum]’s ESP32 Dashboard as a great example, it’s an ESP32 hooked up to an e-paper display. The hardware is simple enough, but the software is what makes it interesting.

This is deigned as a configurable notification tool, so to make it bend to the user’s will a series of widgets can be loaded onto it. The device runs MicroPython, making it easy enough to write more than the ones already on place. The screen is divided into four zones, allowing for a range of widgets to be used at once. All the details can be found in a GitHub repository.

We like it for its configurability and ease of programming, and because it delivers well on the promise of a useful device. An ESP32 and e-ink combination with MicroPython apps is something we’ve seen before in the world of badges.

Word Of The Day Calendar Is Great Use Of E-Paper

October 28, 2024 by 12 Comments

If you’re trying to learn a new language, there are always a lot of words to learn. A word-of-the-day calendar can help, and they’re often readily available off the shelf. Or, you can grab some hardware and build your own, as [daedal-tech] did!

The project was built as a gift to help [daedal-tech]’s partner with their efforts to pick up French. Thus, a Raspberry Pi Zero 2W was employed and paired with a small Waveshare e-Paper display. These were stuffed inside a fancy light switch plate from Hobby Lobby and a small stand, the pair of which act as a pretty nice little frame for the build. The Pi runs a small Python script which employs the BeautifulSoup4 library and the Python Image library. Basically, the script grabs French words and spits them out on the display with a small description such that one might understand their meaning.

It’s a simple build, but one that has some real utility and is fun to boot. We might see more word clocks than calendars around these parts, but we love both all the same!

Hacking An NFC E-Paper Display From Waveshare With Mystery MCU

December 18, 2023 by 15 Comments

These days e-paper (eInk) displays are everywhere, with stores being one of the largest users of smaller, monochrome versions of these persistent displays. This has also made them a solid target of hackers who seek to not only reverse-engineer and reuse discarded ones, but also ones sold to consumers, with [Aaron Christophel] recently reverse-engineering and flashing custom firmware (GitHub source) to a Waveshare 2.13″ NFC-Powered E-Paper display.

What’s perhaps most notable is how locked-down and devoid of documentation these devices are. The board [Aaron] looked at did not have any markings on the main IC, and Waveshare did not provide more information other than the Android and iOS apps. This led to some matching of various NFC-enabled MCUs with the pinout, with the Chivotech TN2115S2 rolling out as the most likely candidate. This is an 8 MHz Cortex-M0 MCU with not only NFC, but also an energy harvesting feature (up to 300 mW), which is why this e-paper tag can update the display without external power or a battery.

With the Chivotech datasheet being rather sparse, more reverse-engineering needed to be done, which included dumping the firmware and exploring it with Ghidra. During this, the secret key was discovered to make the Flash writeable along with how to control the peripherals and display. With this knowledge it’s now possible to make this tag display update without being limited by manufacturer-supplied tools and software, making it infinitely more useful.

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