Mysterious Files PH

With the advent of affordable 2.5 Gbit, 5 Gbit, and 10 Gbit consumer networking gear, more and more people are taking advantage of these higher networking speeds, with [This Does Not Compute] having used 10 Gbit SFP+ modules over regular Cat-5e copper to connect to a NAS in the next room. Only problem was that after a while these SFP+ modules began to start dropping frames. On taking a closer look at these modules, he found that they were running pretty hot: 40°C while idle. A teardown of one of these modules showed severe discoloration due to heat.

Inside these 10Gbit modules is the Marvell-branded Alaska X 88X3310/40P PHY, which despite the ‘low-power’ claims have a metal heatsink glued onto the actual IC and thermally coupled to the module’s metal enclosure. The other side of the PCB was quite discolored, further indicating how hot these modules run in operation. Some digging revealed that this can go up to around 2.5 watts.

Perhaps the most fascinating part of this teardown is the discovery of an 8051-based MCU that’s responsible for telling the switch the module is put into that it is a 30-meter multi-mode fiber module, presumably for compatibility purposes. It’s definitely an interesting feature of these FS-branded SFP+ modules.

These old modules were replaced with Wiitek-branded modules that are supposed to use only up to around 1.5 watts in operation courtesy of a newer chipset, in the hope that these wouldn’t fry themselves. At idle these do however still run at 30 °C. As noted in the comments, it might be a good idea to have active airflow over high-speed networking gear like this, as they generally can get pretty hot and sometimes crispy.

The final solution for the video’s networking problem was to just run single-mode fiber to the room and use appropriate SFP+ modules for that, also because these run noticeably cooler. If you still have room in your cable ducts, that would seem to be the optimal solution.

Few things are more satisfying during a Summer night than hearing the crackle and pop of another mosquito hurling itself against a bug zapper and knowing that it won’t be trying to suck your blood any more. The only problem with those bug zappers, whether the mounted or hand-held type is that you cannot get every single attacking mosquito. Unless you were to put the bug zapper on yourself, of course. This is basically what [Dani Cruster] of the aptly named ‘DiWHY’ channel decided would be the right course of action.

The video is apparently dubbed over from the original Russian – with the team claimed to be based in Moldova – which probably explains a lot of the reasoning behind this engineering. At the core of the whole-body bug zapper is galvanized mesh, with a big question being how close you can get it to the body before said body gets zapped too. With about a millimeter of clearance between both layers of mesh required at 1 kV, this was another design consideration.

Ultimately the guts of stun guns were used, which output around 10 kV and thus require a 1 cm gap between the mesh layers. PVC plates were used to create the structural elements of the walking bug zapper suit, using a heatgun to form it into a body-appropriate shape. That’s when human testing started, to try and not make it zap the wearer.

The final suit of bug zapping armor uses six stun gun modules, each powered by a 3 V power source created from two 1.5 V alkaline cells that are good for an hour of zapping. One issue found during a human trial run was that the zip ties used turned out to actually cause arcing, which had to be addressed first before heading to the mosquito-infested woods. In the video these are said to be near Tarkov in what appears to be the national park in Russia’s Tver Oblast and clearly a prime mosquito breeding ground.

During the real-life test run many mosquitoes and apparently even some ticks find their electrifying demise, before for some reason they seem to clear out after an hour or so. Overall it seems to work well, even if it’s not that ergonomic and things get spicy when it starts to rain.

Although the basic principle of radio direction finding is easy to understand (measure the phase difference between different antennas, then calculate the angle of arrival from this difference), the radio hardware to actually implement this has historically been hard for hackers to access. The QuadRF project aims to change this by building a phase-coherent four-channel SDR which makes direction mapping easy (GitHub repository).

The QuadRF uses two boards: one to receive and pre-process radio waves, and a Raspberry Pi 5 for additional processing. The RF board has four patch antennas, each capable of either transmitting or receiving in the 4.9 GHz to 6.0 GHz range, with switchable right- or left-hand polarization. For on-device processing, it uses a Lattice ECP5 FPGA, which uses two MIPI cables to connect to the camera and display interfaces on the Raspberry Pi. These form a very high-speed data exchange, and after further processing, the Pi can pass data on over Ethernet or Wi-Fi. Individual QuadRF boards can connect together in a lattice grid to form larger phased arrays.

The QuadRF’s software shows off its real strength: it’s compatible with standard programs like GNU Radio, but it also hosts a few of its own programs. The most striking of these is an “RF camera” which scans its entire frequency range at 30 fps, tracking the direction of detected signals and visualizing them on a spatial plot. When overlaid on a camera feed, this plot lets one easily see the radio signals emitted from electronics; as an example, the creators tracked a drone in flight, even distinguishing the two radio transmitters on the drone.

This isn’t the first multi-antenna SDR we’ve seen, though this is the first that could transmit. It’s important to be careful, though: some applications of this kind of hardware run afoul of arms regulations.

Thanks to [Swake] for the tip!

Some municipalities implement bike counters on cycling routes in order to monitor traffic. [nullpxl] recently investigated how these counters work, and explored methods that can be used to trick the counter into thinking a bike passed over it.

A great many of these devices are built using inductive loop sensors. This involves passing a current through a loop of wire embedded in the ground. When a conductive item such as the metal wheel of a bike passes through the electric field, eddy currents are generated in the item, creating their own magnetic field which reacts with the loop’s field itself. This creates a change in inductance which can be measured, and thus used to log the number of times a conductive item has passed over the sensor. By looking at the signature of the inductance change, a system can be tuned to detect specific objects—for example, two bicycle wheels passing over a sensor will create a signal that varies over time in a characteristic way.

[nullpxl] first tried to recreate a “bike” signal for the inductive loop by running over the area holding two metal pans. This wasn’t close enough, so a new idea was needed. Experiments with a scrap bike then indicated that there was a speed gate involved, and that wheeling one wheel over the sensor and back again could trick the sensor into thinking a bike had passed by. Eventually, [nullpxl] distilled all this learning down to create “the BIKE BASKET.” It’s simply a bag with a bike wheel in it, and swinging it over the sensor twice makes the counter tick up.

Is there any money in tricking the average municipal bike counter in your local city? We doubt it, unless Big Bike is getting increasingly filthy in its lobbying efforts. In any case, we love to see weird sensor hacks around these parts.

It’s never been easier to get a printed circuit board made. In fact, almost every electronics video out on the internet will incessantly remind you of this fact now. But making a custom PCB wasn’t always as straightforward as sending a KiCad file to a board house. Many DIY methods involve harsh chemicals and tedious processes, but did have the potential benefit of taking much less time than waiting on boards to arrive in the mail. [Bettina Neumryr] is demonstrating one of these older methods, called the toner transfer method, using a circuit that was printed directly in an old magazine.

The first part of the toner transfer method is to create an image that can be printed. Since this circuit came from a magazine, it is first scanned in to a computer and imported into GIMP, where it can be scaled to match the size of the components and then sharpened to make a crisp print. With the image ready, it’s time to print the image onto some toner transfer paper, ensuring that the printer in question is a laser printer which actually uses toner. From there, a sheet of blank copper PCB is prepared and then the toner is transferred by heating, in this case using a laminator. After that its etched, removing all of the copper not protected by the toner, and then the toner itself can be removed which leaves behind the copper traces.

For those of you who were around when toner transfer was in vogue, this video might not have much value. But for anyone who can’t use a board manufacturer for whatever reason or is looking for alternatives, a modern video showing the method could be much more useful and have better context for beginners than videos made a decade or more ago now. Some of those older methods include similar processes using inkjet printers instead, but there are more modern DIY methods as well using lasers or CNC machines too.

The cool thing about cyberdecks is that you get to design them to suit your personal tastes. [NickZero] wanted an ultra-minimal build, and set about putting together just that.

The build is based around a Raspberry Pi Zero 2W, which has a lighter power draw than the full-fat models at the trade-off of some processing power. Since it’s a W model, it has the benefit of wireless connectivity baked in from the factory. The Pi is paired with a Gherkin 30% layout keyboard kit, which neatly matches the 7″ Waveshare touch display in width. Power is courtesy of a juicy 4000 mAh lithium-ion cell, which is taken care of by an Adafruit Powerboost 1000 charger module. Everything is then laced up together inside a nifty 3D printed case.

It’s a simple cyberdeck, and one that’s probably quite satisfying to use when you get used to the fact that there are no number or modifier keys on the ultra-cut-down keyboard. It’s also a great example of how a bunch of off-the-shelf gear can nonetheless be assembled into quite a cohesive whole. In much the opposite way, we’ve seen some maximalist cyberdeck builds lately, too.

Things are back to normal around the Podcast studio, and this week you’ll hear the dulcet tones of Elliot Williams and Kristina Panos.

In Hackaday news, we still have a Frikkin’ Lasers Challenge going on, and now you can even enter your project into it! Join the ranks, won’t you?

Not only do we have a triple mailbag this week, we have another failed attempt at guessing the sound by Kristina. However, [Baron Maximilian von Knuthausen] knew that it was a train, a British one, even. Then it’s on to the hacks, of course, which ought to go far in explaining the show title.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download in lovely MP3.

Episode 374 Show Notes:

News:

• The Frikkin Lasers Contest Starts Now (a couple weeks ago, that is).

Mailbag:

• Triple scoop! [Brett Gibson] asked whether the Hackaday Europe talks will be posted, [AT] dreams of electric tweezers, and we have an audio missive from [Shlomo Yitzchak Kaganoff], who wants to know what the most elaborate and/or interesting home automation is that exists. Can you weigh in? Of course you can. Will you?
• Found Footage: Elliot Williams Talks Nexus Technologies

Interesting Hacks of the Week:

• Behold A 60 Hz Refresh Rate E-ink Monitor
  • Supercon 2024: Wenting Zhang – Making E-Ink Go Fast – YouTube
• Commodore Unveils Linux Powered Flip Phone
• OpenCAL: Computed Axial Lithographic 3D Printing For Everyone
  • CAL 3D Printing Spins Resin Right Round, Baby
  • Prints in Seconds – NOW OPEN SOURCE! Computed Axial Lithography! – YouTube
• Wooden Piano Keys Hold Your Less-Wooden, Not-Piano Keys
• Building A Ceiling-Based Crane Robot To Keep A Room Clean
  • lerobot (LeRobot)
  • Cable Bots, Arise! Domination Of The Universe Is At Hand
• Ergonomic Mouse Gives Each Fingertip Its Own Saddle

Quick Hacks:

• Elliot’s Picks:
  • 2026 Frikkin Lasers Contest: Glow Engine Is Like An Open Air Slow Scan CRT
  • 2026 Frikkin Lasers Contest: Steampunk, 360 O-Scope Does It With Tubes
  • The Pacemaker Patch
  • IKEA Storage Box Just Happens To Make Great Printer Cover
• Kristina’s Picks:
  • 3D Printed Hose Sprayer Sets Phasers To Suds
  • Adding Weight To A 3D Print With Plaster Of Paris, Cleanly
  • Homebrew Macropad Looks Good

Can’t-Miss Articles:

• What Happens If Russia Shuts The Door On Their Leaky ISS Module?
• How Did They Make View-Master Slides?
  • Inexpensive Reading Glasses Become Stereoscope