Building A Wireless Fingerprint Authorization Device

July 3, 2026 by Zoe Skyforest 12 Comments

Once upon a time, there was a bit of a fad for fingerprint authentication in laptops and desktop computers. It has long since faded, but [superdog] wanted just such a device for Linux and Mac machines. Thus, it was time to build one.

[superdog] designed the device, nicknamed immurok, as a tool for people who use external keyboards, and do lots of terminal work on Mac and Linux machines. Repeat password requests can interrupt one’s flow when hustling at the keys, so immurok was designed to ease this pain.

The device is based on a WCH CH592F microcontroller, which comes with Bluetooth connectivity out of the box. This allows immurok to connect wirelessly to the machine of your choice, advertising itself as a standard Bluetooth HID keyboard device. Fingerprint-wise, scanning is done with an R559S capacitive sensor, which verifies the match locally so there’s no transmitting biometric data anywhere. On the computer side, Linux is setup to use a CLI/TUI app plus PAM integration to handle authorization for system logins and sudo in the terminal. On the Mac platform, it’s used with a menu bar app, with PAM integration for admin prompts. There’s also a separate helper path for using it with the lock screen.

If you’re sick of entering your password all the time and wish unlocking your PC was more like unlocking your phone, this might be the project for you. We’ve seen similar projects before, too. If you’re whipping up fun gear for biometric auth, don’t hesitate to let us know on the tipsline.

Watch A Steam Controller Skitter Itself To Its Charge Puck

July 1, 2026 by Donald Papp 12 Comments

Hacks don’t have to be practical but it helps if they are educational or clever or amusing, as [Ray Foss] demonstrates with his auto-docking Steam Controller.

It’s an open-source web application that combines a camera, a Steam Controller, and some clever software for the sole purpose of saving the user from the tyranny of having to manually set the controller onto its magnetic charging puck. Instead, one can simply lay the controller down nearby and let the computer do the rest of the work.

First one fires up the web interface, ensures a webcam has a good top-down view of both the charging puck and the controller, connects wirelessly to the controller, then clicks a few points on the camera view to tell the system where things are.

After that, the system buzzes the controller’s haptic feedback motors to make it skitter across the desktop until — guided by the camera and implementing obstacle avoidance — it docks successfully with its magnetic charging puck.

It may not be super practical and may even seem a bit Rube Goldberg-esque, but it’s fun and demonstrates a few interesting things. One is moving a controller via slip-stick friction by asymmetrically pulsing the feedback motors. Another is automatically reducing the pulse frequency to make smaller movements when it gets close to the charging puck, for finer control.

The computer vision part also ignores anything in expected cable locations, removing the need to deal with them algorithmically. WebHID via the browser takes care of talking to the controller, and confirming a successful docking by watching messages to detect when charging has begun.

If this seems a bit familiar, it’s because this project was inspired by the work of [Very Lazy Pixels] which we covered previously.

A Custom Zigbee Touch Keypad

June 26, 2026 by Zoe Skyforest 8 Comments

[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 T9 Keyboard For Your Smartphone

June 24, 2026 by Zoe Skyforest 15 Comments

These days, most of us are fortunate enough to use smartphones with decent touchscreen keyboard capabilities. However, once upon a time, if you wanted to type something on a phone, you had to tap it out on the number keys instead. [Jarrett] is bringing that back with a custom T9 keyboard for modern phones.

The build is designed around the keypad of the Nokia E52, a Symbian smartphone released in 2009—two years after Apple changed the game with the first iPhone. The phone keypad itself is laid over a custom PCB with Alps SKRK tactile switches corresponding to each individual key. Each is wired with a diode and the switches are scanned as a row/column array as is typical for keyboards. Reading the matrix is an ESP32-C6 microcontroller, which counts the keypresses and spits out the right letters over its Bluetooth connection to an attached smartphone or other device. Power is via a small lithium-ion battery, looked after by a TP4200 charger chip.

Overall, the keyboard works as you’d expect, allowing T9-style input to any compatible device that works with Bluetooth keyboards. [Jarrett] does have one regret, with the 0.98 N actuation force switches used leaving he keypad feeling a little mushy. The firmer 1.57 N switches were suspected to give a more satisfying response under thumb, which was a nice upgrade in the second revision build.

We’ve seen other builds in this vein before, too, albeit with bigger keys. If you’re coming up with your own esoteric input methods, don’t hesitate to notify the tipsline.

Ergonomic Mouse Gives Each Fingertip Its Own Saddle

June 15, 2026 by Donald Papp 5 Comments

Want to make your own ergonomic mouse but don’t know where to start? Why not try [psudoku]’s Kotinos design?

It’s a scaffold-like fingertip shell that uses the internals of an HSK Pro mouse. Each fingertip gets its own little saddle-shaped nook, and things like hand size and paddle surface can all be configured by modifying the OpenSCAD scripts.

[psudoku]’s unit looks to us as though it was maybe made using multi-jet fusion (MJF) 3D printing, but it should be perfectly printable on hobbyist printers, whether resin- or filament-based.

Comfort of the contact surfaces is left up to the end user, but if your print lacks smoothness and sanding isn’t your jam, you might consider a layer of fabric tape to create a velvet-like surface on a 3D print. That’s a trick we’ve kept in mind ever since seeing it put to good use, cushioning the hardware in a DIY steam deck case.

Is the minimalist scaffold approach to a mouse not your style, or does your hand crave something less lightweight but a little more personalized? You might want to craft a truly custom-fitted mouse, for which clay is the way.

Behold A 60 Hz Refresh Rate E-ink Monitor

June 13, 2026 by Donald Papp 51 Comments

E-ink displays have a number of advantages over other display types, but their refresh rate isn’t one of them. But what exactly makes them slow? According to [Wenting Zhang], it’s not an inherent limitation of the technology. It’s mainly the controller, and this limitation can be overcome to create a high-resolution 60 Hz refresh rate E-ink display, totally suitable for use as a computer monitor.

The reason E-ink displays are so slow is simple. For a long time, they existed for only one purpose: to be screens for e-readers. They had to work on devices that were generally low power, with limited interfaces and slow processors. Accommodating these factors was the primary driver behind the high latency and slow refresh rates associated with these displays.

It was actually the limited interface options rather than the slow refresh that initially led to a custom controller, because [Wenting] wanted to use an E-ink display on a laptop build. But it quickly became apparent that a custom controller could do considerably more than E-ink was known for.

Initial tests with fast refresh rates were so positive that it led to a Hackaday Supercon 2024 talk on how to make E-ink go fast, and more recently has culminated in the Modos Flow, a fully open-source, user-repairable 13.3″ portable E-ink monitor.

The development path from proof of concept to finished product has been a long one for [Wenting]. Not only did a lot of optimization and feature work need to be crafted from scratch in order to effectively balance appearance with responsiveness in different display modes, but the usual hassles of development and bad timing were also in full force. On top of it were wasteful vendor shenanigans, as well.

Check out the story in the video, embedded just below. If you’d like to buy one, there are monochrome and color versions offered through Crowd Supply.

Continue reading “Behold A 60 Hz Refresh Rate E-ink Monitor” →

Pi Pico Puts Bluetooth Keyboards On The I2C Bus

June 6, 2026 by Tom Nardi 2 Comments

If you’ve ever worked with I2C, you know its one of those things that makes working with modern microcontrollers such a pleasure. With a few wires and not many more lines of code, you can communicate with all sorts of hardware such as sensors, displays, and input devices. There are even I2C keyboards out there, although they tend to be a bit pokey — and not in the good way as it pertains to keyboards.

But the bt2i2c project from [Roberto Alsina] promises to improve things. With his firmware flashed to a Pi Pico W, you can establish a connection with any standard Bluetooth keyboard and have the keystrokes sent over the wire via I2C. As far as your project is concerned, the input will appear to be coming from a BlackBerry BBQ20/BBQ10 keyboard using the address 0x1F, which means that there’s already plenty of code out there to work with. While [Roberto] explains its not strictly necessary, connecting a ST7789 display to the Pi Pico over SPI will give you some visual feedback on connection status.

As microcontrollers become increasingly powerful and capable of the sort of thing we would once have done on a “real” computer, a project like this has some fascinating potential. We’ve seen a number of “writerdeck” projects running on chips like the ESP32, and it’s not hard to see the appeal of being able to easily pair your favorite Bluetooth keyboard up to one of them.