A Custom Zigbee Touch Keypad

June 26, 2026 by Zoe Skyforest 1 Comment

[Dominic Buchstaller] wanted a neat, tidy entryway keypad that actually looked good. Prime goals were something slim, wireless, and with no visible screws. Dependency on the cloud was also a no-go. With few ready-to-go options available on the market, he set about whipping up his own.

The heart of the build is an ESP32-C6 microcontroller devboard. This device has the benefit of including Zigbee communication functionality baked right into the chip. It’s hooked up to an MPR121 capacitive touch controller, which allows different segments of the touchpad PCB to act as capacitive buttons for numerical entry. The number labels are directly printed on the PCB solder mask, so there’s no overlay or other label required on top. Power is courtesy of a 1300 mAh lithium-polymer cell which gives a useful lifespan of six months between recharges. A simple 3D-printed case holds everything together and completes the clean and simple look. [Dominic] notes that it’s possible to also use the device via Matter or Thread without a lot of changes, as the ESP32-C6 can easily handle those protocols, too.

If you’re looking for a cheap, handsome keypad for your Home Assistant setup or similar, you might find this useful. We’ve explored DIY keypad entry systems before, too. If you’ve come up with some other creative way to get into your house, car, or bank vault, be sure to notify us via the tipsline.

A GUI Solution For ESP32 Web Development

June 26, 2026 by Zoe Skyforest 12 Comments

These days, a lot of embedded projects feature some sort of screen, and a screen often creates a desire for a nice user interface. [Geoffrey Wells] has created a tool for developing web interfaces for the ESP32, named ESP-GenUI.

The aim was to make UI development as easy as possible for this platform. ESP-GenUI allows the creation of a website by dragging various nodes on to a canvas and linking them up to create the desired web interface. There are nodes for GPIO control, camera feeds, gauges, and all sorts of other common elements for quickly putting together dashboards and control panels. All this is done from within the browser, and the code generated by the tool can even be flashed without having to open any external tools. Alternatively, it can spit out Arduino code that you can open and flash from within the IDE. You can try the tool out yourself right here.

We’ve featured some other great resources for developing embedded user interfaces, like this highly-flexible display library for the ESP32. Feel free to espouse on your own favorite tools and techniques in the comments.

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CSS On The ESP32

June 25, 2026 by Zoe Skyforest 14 Comments

There are lots of graphics libraries available for the ESP32, and lots of ways to program one to boot. Even still, most of us wouldn’t immediately think to CSS when it comes to embedded products — yet that’s now a thing on the Espressif platform, apparently.

The Gea stack allows one to compose CSS and TypeScript code that is then turned into generated C++ code that compiles to native firmware. The team behind Gea have demoed this ability by running a 3D cube animation on an ESP32 at up to 60 FPS. This isn’t some ugly, low-res wireframe demo, either. It’s a full-color animation running on a 410×502 AMOLED screen. It’s very fluid, and can even handle transparency on the cube faces (albeit with a performance penalty).

It’s worth noting that this isn’t a full browser engine. As you might expect, some concessions had to be made to get it running on the ESP32. Namely, it doesn’t handle “:hover” states because it’s designed for touchscreen use, fonts are rasterized, and the UI tree is limited to just 512 nodes. Regardless, it shows that using CSS and TypeScript to develop for the ESP32 is entirely possible without some crazy loss of performance. If you want to build easy interfaces on an ESP32 while leaning on web dev experience, this could be very useful indeed.

There are lots of fun ways to write code for the ESP32; you can even try MicroPython if you like.

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A More Convenient IButton Reader

June 24, 2026 by Zoe Skyforest 3 Comments

iButtons are microchips housed in small, round, metal containers, and are similar to coin cell batteries in appearance. Among other things, they’re used for logging data in industrial contexts, particularly where it’s desirable to track parameters like temperature over time. [Geoffrey Wells] has worked with these sensors, and decided that the aging solutions for reading these devices are too cumbersome and out-of-date. Thus, he designed ChillPoint as a more modern solution.

As you might have guessed by the name, [Geoffrey] was inspired to build a rig specifically for inspecting iButton data loggers in cold chain logistics applications. It’s built around an ESP32-C6, which has a 1-Wire probe on the front for communicating with the target device. On contact, the reader dumps all the data, storing it on its own flash storage. The data can then further be accessed by connecting to the ChillPoint handheld device over its own WiFi access point, upon which it hosts a web UI for access. The handheld can be used for scanning iButtons single-handed, while a smartphone, tablet, or laptop can be used as a screen to monitor the results live.

The project is nearing completion, and [Geoffrey] says both the hardware and software will be open source once it’s all said and done. Anyone interested in adding a ChillPoint to their toolbox should keep an eye out for its upcoming CrowdSupply campaign.

If you find yourself working with these devices on the regular, this project may be appealing to you. We’ve looked at iButtons many times over the years. The Java Ring was probably the coolest.

This Alarm Clock Has The Capacity To Wake You

June 15, 2026 by Jenny List 12 Comments

Every now and then a project comes into the Hackaday feed that has so many levels of wrong about it that you really shouldn’t do it at home, but is amusing enough to feature anyway with a warning. So it is with [ArcaEge]’s Capacitor Alarm Clock, which wakes up its unfortunate owner by blowing up electrolytic capacitors with reverse voltage. If you survive, you’ll certainly be awake!

It’s inspired unsurprisingly by an [ElectroBoom] video, and the premise is simple enough. An ESP32 serves as the clock, and triggers a relay for the alarm, which in turn overloads a suitably low-voltage electrolytic capacitor in a socket. The resulting explosion which appears in a video we’ve placed below the break, wakes the slumberer.

We don’t have to tell you that this is not the safest of hacks, and is presented here only for your entertainment. But it does provide a few points of interest, for example in identifying the difference between capacitors with a vent, and those without.

This isn’t the first time we’ve seen a project based around exploding capacitors, and that one maybe was a don’t-do-this-at-home too.

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Ebike Display Uses Reflective LCD

May 31, 2026 by Bryan Cockfield 19 Comments

Although LCD displays have been used in almost every type of consumer electronics display over the last two decades, many of these screens have a few downsides that limit their usefulness in certain situations. As any owner of an early digital watch, an early laptop, or an early digital camera will testify, these displays often completely fail in direct sunlight. And, a currently new technology often using inexpensive displays in full sunlight conditions is ebikes, so [Volos Projects] decided to use a unique LCD display to solve this issue.

The display is called a reflective LCD (RLCD) and is actually a fairly old but overlooked piece of technology. Displays like these have a reflective layer that bounces ambient light back to the user, increasing contrast and readability in high light, especially when compared to more common transmissive displays. This build is based on a board from Waveshare, which includes the screen and its driver components, and [Volos Projects] integrated this into a test stand that mimics an ebike’s speed sensor and other hardware like turn signals. The display shows the bike’s speed and a few other indicators, and thanks to the screen, this information can be easily seen in full sun.

Although he doesn’t have it on an actual e-bike yet, he hopes it will be useful for those who want to try out something like this with their substandard e-bike displays. The code he’s used is available on a GitHub page for anyone interested. We’d imagine that a low-cost display like this would pair well with an open-source ebike like this one.

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ESP-Osito Eschews Retrocomputing For Modern Code On Modern, Equivalent Hardware

May 29, 2026 by Tyler August 12 Comments

If you’re of a certain vintage, you have probably looked at some of the microcomputers on the market these days and thought “that would have been a decent workstation back in the day!”. We certianly have, and so did [Roberto Alsina]. Rather than allow himself to contemplate his age and threfore rapidly approaching mortailty, [Roberto] wrote a useful operating system called ESP-Osito for the Cheap Yellow Display, which he refers to as “the cheapest computer”. He’s not wrong, and it’s certainly a better use of time than an existential crisis.

He explains some of his reasoning behind the project in an accompanying blog post, but on the project page he compares it to a Palm Pilot– it’s on quick, apps load quick, and the API is simple enough for easy app creation in a few hundred lines of C, unlike certain pocket computers we won’t name. Sure, there’s no multitasking, but when apps jump from SD card to run in memory in microseconds, who cares? Saving the current state of the app back to SD means the experience is virtually identical from a user perspective anyway.

DOS knew what time it was, but how many of us wasted phone time for weather reports?

As this is a one-man show for now, the app store won’t quite rival your smart phone– but there’s everything you’d expect on the 90s-era computer this has the horsepower of: a serial terminal, a text editor, a file explorer, a calculator, a clock, but also some things that aren’t so retro. The clock app gives weather info via futuristic wireless networking, the reader app takes Markdown text, and the chat app connects to an LLM somewhere instead of your friends on IRC. The blackberry keyboard option gives it a feel of a slightly different vintage. You can also play snake, because no computer is complete without games. The OS and all its applications are released under the MIT license on GitHub, and [Roberto] is actively looking for collaborators.

If you doubt the workstation comparison at the start of this article, this CYD runs Macintosh System 3 via a 68k emulator. That’s got old-school cred, but there’s something great about having retro constraints with modern code on modern hardware. In that way, ESP-Osito is similar to the 3D graphics engine behind this Wipeout clone.