Day: August 30, 2025

Open source mute button

Silent No More: Open-Source Fix For Mic Mishaps

August 30, 2025 by 2 Comments

“Sorry, my mic was muted…” With the rise of video calls, we’ve all found ourselves rushing to mute or unmute our mics in the midst of a call. This open-source Mute Button, sent in by [blackdevice], aims to take out the uncertainty and make toggling your mic easy.

It’s centered around a small PIC32MM microcontroller that handles the USB communications, controls the three built-in RGB LEDs, and reads the inputs from the encoder mounted to the center of this small device. The button knob combo is small enough to easily move around your desk, yet large enough to toggle without fuss when it’s your turn to talk.

To utilize all the functions of the button, you’ll need to install the Python-based driver on your machine. Doing so will let you not only toggle your microphone and volume, but it will also allow the button to light up to get your attention should you be trying to talk with the mic muted.

Although small, it’s also quite rugged, knowing it will spend its life being treated much like a game of Whac-A-Mole—slapped whenever needed. The case is designed to be 3D printed by any FDM printer, with the top knob section printed in translucent material to make the notification light clearly visible.

All of the design files, firmware, and parts list are available over on [blackdevices]’s GitHub page, and they are open-source, allowing you to tweak the design to fit your unique needs. Thank you for sending in this well-documented project, [blackdevices]; we look forward to seeing future work. If you like this type of thing, be sure to check out some of our other cool featured desk gadgets.

Continue reading “Silent No More: Open-Source Fix For Mic Mishaps” →

A wrench is shown lying on a machinist’s mat. The end of the wrench holds a ratcheting wheel, on top of which are six independent metal blocks arranged into a hexagon.

Building A Shifting Ratchet Wrench

August 30, 2025 by 3 Comments

Convenient though they may be, [Trevor Faber] found some serious shortcomings in shifting spanners: their worm gears are slow to adjust and prone to jamming, they don’t apply even force to all faces of a bolt head, and without a ratchet, they’re rather slow. To overcome these limitations, he designed his own adjustable ratchet wrench.

The adjustment mechanism is based on a pair of plates with opposing slots; the wrench faces are mounted on pins which fit into these slots, and one plate rotates relative to the other, the faces slide inwards or outwards. A significant advantage of this design is that, since one plate is attached to the wrench’s handle, some of the torque applied to the wrench tightens its grip on the bolt. To let the wrench loosen as well as tighten bolts, [Trevor] simply mirrored the mechanism on the other side of the wrench. Manufacturing proved to be quite a challenge: laser cutting wasn’t precise enough for critical parts, and CNC control interpolation resulted in some rough curves which caused the mechanism to bind, but after numerous iterations, [Trevor] finally got a working tool.

To use the wrench, you twist an outer ring to open the jaws, place them over the bolt, then let them snap shut. One nice touch is that you can close this wrench over a bolt, let go of it, and do something else without the wrench falling off the bolt. Recessed bolts were a bit of an issue, but a chamfer ought to improve this. It probably won’t be replacing your socket set, but it looks like it could make the odd job more enjoyable.

If you prefer a more conventional shifting wrench, you can make a miniature out of an M20 nut. It’s also possible to make a shifting Allen wrench.

Continue reading “Building A Shifting Ratchet Wrench” →

Octos background with hackaday website pulled up

Open Source Interactive Wallpapers For Windows

August 30, 2025 by 7 Comments

It’s late at night, and you’re avoiding work that was supposed to be done yesterday. You could open an application on your desktop to keep your attention, or what about the desktop itself? [Underpig1] has you covered with Octos. Octos is an open-source application created to allow interactive wallpapers based on HTML, CSS, or JS for Windows 10 and 11.

There are many wallpaper applications made to spruce up your desktop, but Octos stands out to us here at Hackaday from the nature of being open source. What comes along with the project is a detailed API to reference when creating your own wallpaper. Additionally, this allows for detailed and efficient visualization techniques that would otherwise be difficult to display, perfect for procrastination.

Included demos range from an interactive solar system to Conway’s Game of Life. Customization options allow for basic manipulation of the backdrops in the application itself, but we’re sure you could allow for some fun options with enough tinkering.

If you want to try Octos out for yourself, it’s incredibly easy. Octos can be found on the Microsoft Store, and additional backdrops can be added within the application. Open-source applications allow for incredibly easy additions to your personal device, but it’s not always that way. Kindle has been a prime example of a fairly locked down system; however, that never stops a clever hacker!

Thanks to [Joshua Throm] for the tip!

FPGA Brings UNIX V1 To The DEC J-11

August 30, 2025 by 5 Comments

If you’ve never used a PDP-11 before it’s probably because you simply weren’t around in the 70s and 80s. Although they started as expensive machines only in research labs and industry, they eventually became much more accessible. They’re a bit of a landmark in computing history, too, being largely responsible for the development of things like UNIX and the C programming language. [ryomuk] is using an FPGA in combination with an original DEC J-11 to bring us a new take on this machine. (Google Translate from Japanese)

The FPGA used in this build is a Tang Nano 20k, notable for its relatively low cost. The FPGA emulates the memory system and UART of a PDP-11 system down to the instruction set, while the original, unmodified DEC chip is left to its own devices. After some initial testing [ryomuk] built a PC11 paper tape emulator to ensure the system was working which runs a version of BASIC from the era. The next thing up was to emulate some disk drives and co-processors so that the machine can run the first version of UNIX. 

[ryomuk] also developed a PCB for the DEC microprocessor and the FPGA to sit on together, and it includes all of the jumpers and wiring needed to allow the computer to run UNIX, as well as handling other miscellaneous tasks like power. It’s an interesting build that gets to the heart of the early days of computer science. PDP-11 computers did eventually get smaller and more accessible, and if you want to build a modern version this build fits a complete system into an ATX case.

Thanks to [RetepV] for the tip!

A 3D-printed case encloses a number of electronic components. In the top left of the case, a laser diode is mounted. In the top right, the laser beam is shining into a cuvette, which is glowing red from scattered light. In the bottom right, a small breadboard has an integrated circuit and a few parts mounted. In the bottom left is a large red circuit board marked “Rich UNO R3.”

Measuring Nanoparticles By Scattering A Laser

August 30, 2025 by 6 Comments

A fundamental difficulty of working with nanoparticles is that your objects of study are too small for an optical microscope to resolve, and thus measuring their size can be quite a challenge. Of course, if you have a scanning electron microscope, measuring particle size is straightforward. But for less well-equipped labs, a dynamic light scattering system, such as [Etienne]’s OpenDLS, fits the bill.

Dynamic light scattering works by shining a laser beam into a suspension of fine particles, then using a light sensor to measure the intensity of light scattered onto a certain point. As the particles undergo Brownian motion, the intensity of the scattered light changes. Based on the speed with which the scattered light varies, it’s possible to calculate the speed of the moving particles, and thus their size.

The OpenDLS uses a 3D printed and laser-cut frame to hold a small laser diode, which shines into a cuvette, on the side of which is the light sensor. [Etienne] tried a few different options, including a photoresistor and a light sensor designed for Arduino, but eventually chose a photodiode with a two-stage transimpedance amplifier. An Arduino samples the data at 67 kHz, then sends it over serial to a host computer, which uses SciPy and NumPy to analyse the data. Unfortunately, we were about six years late in getting to this story, and the Python program is a bit out of date by now (it was written in Python 2). It shouldn’t, however, be too hard for a motivated hacker to update.

With a standard 188 nm polystyrene dispersion, the OpenDLS calculated a size of 167 nm. Such underestimation seemed to be a persistent issue, probably caused by light being scattered multiple times. More dilution of the suspension would help, but it would also make the signal harder to measure, and the system’s already running near the limits of the hardware.

This isn’t the only creative way to measure the size of small particles, nor even the only way to investigate small particles optically. Of course, if you do have an electron microscope, nanoparticles make a good test target.