Rachel Wong Keynote: Growing Eyeballs In The Lab And Building Wearables That Enhance Experience

The keynote speaker at the Hackaday Belgrade conference was Rachel “Konichiwakitty” Wong presenting Jack of All Trades, Master of One. Her story is one that will be very familiar to anyone in the Hackaday community. A high achiever in her field of study, Rachel has learned the joy of limiting how much energy she allows herself to expend on work, rounding out her life with recreation in other fascinating areas.

There are two things Rachel is really passionate about in life. In her professional life she is working on her PhD as a stem cell researcher studying blindness and trying to understand the causes of genetic blindness. In her personal life she is exploring wearable technology in a way that makes sense to her and breaks out of what is often seen in practice these days.

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The door-unlocking mechanism, featuring a 3D printed bevel gear and NEMA 17 stepper.

Hack Swaps Keys For Gang Signs, Everyone Gets In

How many times do you have to forget your keys before you start hacking on the problem? For [Binh], the answer was 5 in the last month, and his hack was to make a gesture-based door unlocker. Which leads to the amusing image of [Binh] in a hallway throwing gang signs until he is let in.

The system itself is fairly simple in its execution: the existing deadbolt is actuated by a NEMA 17 stepper turning a 3D printed bevel gear. It runs 50 steps to lock or unlock, apparently, then the motor turns off, so it’s power-efficient and won’t burn down [Binh]’s room.

The software is equally simple; mediapipe is an ML library that can already do finger detection and be accessed via Python. Apparently gesture recognition is fairly unreliable, so [Binh] just has it counting the number of fingers flashed right now. In this case, it’s running on a Rasberry Pi 5 with a webcam for image input. The Pi connects via USB serial to an ESP32 that is connected to the stepper driver. [Binh] had another project ready to be taken apart that had the ESP32/stepper combo ready to go so this was the quickest option. As was mounting everything with double-sided tape, but that also plays into a design constraint: it’s not [Binh]’s door.

[Binh] is staying in a Hacker Hotel, and as you might imagine, there’s been more penetration testing on this than you might get elsewhere. It turns out it’s relatively straightforward to brute force (as you might expect, given it is only counting fingers), so [Binh] is planning on implementing some kind of 2FA. Perhaps a secret knock? Of course he could use his phone, but what’s the fun in that?

Whatever the second factor is, hopefully it’s something that cannot be forgotten in the room. If this project tickles your fancy, it’s open source on GitHub, and you can check it out in action and the build process in the video embedded below.

After offering thanks to [Binh] for the tip, the remaining words of this article will be spent requesting that you, the brilliant and learned hackaday audience, provide us with additional tips.

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Announcing The 2025 Pet Hacks Winners

When you really love your pawed, feathered, or scaled friends, you build projects for them. (Well, anyway, that’s what’s happened to us.) For the 2025 Pet Hacks Challenge, we asked you to share your favorite pet-related hacks, and you all delivered. So without further ado, here are our favorites, as well as the picks-of-the-litter that qualified for three $150 DigiKey gift certificates. Spoiler alert: it was a clean sweep for team cat.

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A black PCB is shown, with an Arduino Nano mounted in the bottom left corner. The rest of the space on the PCB is used up by ten DIP integrated circuits and a few resistors and diodes. Several black and red wires connect different parts of the PCB.

Meowsic Keyboard MIDI Adapter Aims For Purrfection

Both small children and cats have a certain tendency to make loud noises at inopportune times, but what if there were a way to combine these auditory effects? This seems to have been the reasoning behind the creation of the Meowsic keyboard, a children’s keyboard that renders notes as cats’ meows. [Steve Gilissen], an appreciator of unusual electronic instruments, discovered that while there had been projects that turned the Meowsic keyboard into a MIDI output device, no one had yet added MIDI input to it, which of course spurred the creation of his Meowsic MIDI adapter.

The switches in the keys of the original keyboard form a matrix of rows and columns, so that creating a connection between a particular row and column plays a certain note. [Steve]’s plan was to have a microcontroller read MIDI input, then connect the appropriate row and column to play the desired note. The first step was to use a small length of wire to connect rows and columns, thus manually mapping connections to notes. After this tedious step, he designed a PCB that hosts an Arduino Nano to accept input, two MCP23017 GPIO expanders to give it enough outputs, and CD4066BE CMOS switches to trigger the connections.
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Network Infrastructure And Demon-Slaying: Virtualization Expands What A Desktop Can Do

The original DOOM is famously portable — any computer made within at least the last two decades, including those in printers, heart monitors, passenger vehicles, and routers is almost guaranteed to have a port of the iconic 1993 shooter. The more modern iterations in the series are a little trickier to port, though. Multi-core processors, discrete graphics cards, and gigabytes of memory are generally needed, and it’ll be a long time before something like an off-the-shelf router has all of these components.

But with a specialized distribution of Debian Linux called Proxmox and a healthy amount of configuration it’s possible to flip this idea on its head: getting a desktop computer capable of playing modern video games to take over the network infrastructure for a LAN instead, all with minimal impact to the overall desktop experience. In effect, it’s possible to have a router that can not only play DOOM but play 2020’s DOOM Eternal, likely with hardware most of us already have on hand.

The key that makes a setup like this work is virtualization. Although modern software makes it seem otherwise, not every piece of software needs an eight-core processor and 32 GB of memory. With that in mind, virtualization software splits modern multi-core processors into groups which can act as if they are independent computers. These virtual computers or virtual machines (VMs) can directly utilize not only groups or single processor cores independently, but reserved portions of memory as well as other hardware like peripherals and disk drives.

Proxmox itself is a version of Debian with a number of tools available that streamline this process, and it installs on PCs in essentially the same way as any other Linux distribution would. Once installed, tools like LXC for containerization, KVM for full-fledged virtual machines, and an intuitive web interface are easily accessed by the user to allow containers and VMs to be quickly set up, deployed, backed up, removed, and even sent to other Proxmox installations. Continue reading “Network Infrastructure And Demon-Slaying: Virtualization Expands What A Desktop Can Do”

The Blackberry Keyboard: How An Open-Source Ecosystem Sprouts

What could happen when you open-source a hardware project?

No, seriously. I hold a fair few radical opinions – one is that projects should be open-source to the highest extent possible. I’ve seen this make miracles happen, make hackerdom stronger, and nourish our communities. I think we should be publishing all the projects, even if incomplete, as much as your opsec allows. I would make ritual sacrifices if they resulted in more KiCad projects getting published, and some days I even believe that gently bullying people into open-sourcing their projects can be justified. My ideal universe is one where companies are unable to restrict schematics from people getting their hardware, no human should ever hold an electronics black box, by force if necessary.

Why such a strong bias? I’ve seen this world change for the better with each open-source project, and worse with closed-source ones, it’s pretty simple for me. Trust me here – let me tell you a story of how a couple reverse-engineering efforts and a series of open-source PCBs have grown a tree of an ecosystem.

A Chain Of Blackberry Hackers

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My Winter Of ’99: The Year Of The Linux Desktop Is Always Next Year

Growing up as a kid in the 1990s was an almost magical time. We had the best game consoles, increasingly faster computers at a pace not seen before, the rise of the Internet and World Wide Web, as well the best fashion and styles possible between neon and pastel colors, translucent plastic and also this little thing called Windows 95 that’d take the world by storm.

Yet as great as Windows 95 and its successor Windows 98 were, you had to be one of the lucky folks who ended up with a stable Windows 9x installation. The prebuilt (Daewoo) Intel Celeron 400 rig with 64 MB SDRAM that I had splurged on with money earned from summer jobs was not one of those lucky systems, resulting in regular Windows reinstalls.

As a relatively nerdy individual, I was aware of this little community-built operating system called ‘Linux’, with the online forums and the Dutch PC magazine that I read convincing me that it would be a superior alternative to this unstable ‘M$’ Windows 98 SE mess that I was dealing with. Thus it was in the Year of the Linux Desktop (1999) that I went into a computer store and bought a boxed disc set of SuSE 6.3 with included manual.

Fast-forward to 2025, and Windows is installed on all my primary desktop systems, raising the question of what went wrong in ’99. Wasn’t Linux the future of desktop operating systems?

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