Qron0b: A Minimalist, Low-Power BCD Wristwatch

January 2, 2026 by Maya Posch 19 Comments

Over the decades we have seen many DIY clocks and wrist watches presented, but few are as likely to get you either drawing in the crowds, or quietly snickered at behind your back, as a binary watch of some description does. A wrist watch like [qewer]’s qron0b project which also uses BCD encoding to display the current time is among our more rare project types here, with us having to go all the way back to 2018 for a similar project as well as a BCD desk clock.

As is typical, a single CR2032 coin cell powers the entire PCB, with an ATtiny24A or compatible as the MCU, a DS1302 RTC and the requisite 4×4 LED matrix to display the hours and minutes. Technically three LEDs are unneeded here, but it looks nicely symmetrical this way, and the extra LEDs can be used for other tasks as the firmware is expanded from the current setting and reading of the time.

The AVR C firmware can be found in the above linked GitHub repository, along with the KiCad PCB project and FreeCAD design files for the watch body. The body accepts a 22 mm GT2/GT3-style watch strap to complete the assembly. With a single CR2032 you’re assured of at least a few months of runtime.

Jailbreaking The Amazon Echo Show

January 2, 2026 by Maya Posch 12 Comments

As locked-down as the Amazon Echo Show line of devices are, they’re still just ARM-based Android devices, which makes repurposing it somewhat straightforward as long as what you want is another Android device.

Running Home Assistant on an Echo Show 8 with LineageOS. (Credit: Dammit Jeff, YouTube) — Running Home Assistant on an Echo Show 8 with LineageOS.

In this case, we’re talking about the first-generation Amazon Echo Show 8, which is a 2019-era device that got jailbroken back in November by [Rortiz2]. The process was then demonstrated in a video by [Dammit Jeff].

Currently only two devices are supported by this jailbreak, with the Echo Show 5 being the other one. If there’s enough interest, there doesn’t appear to be any technical reason at least for why this support couldn’t be extended to other devices. One major reason for jailbreaking is to put LineageOS on your Echo device courtesy of these Echo Show devices recently beginning to show advertisements, with no way to disable this.

The process of jailbreaking and installing the LineageOS ROM is somewhat long as usual, with plenty of points where you can make a tragic mistake. Fortunately it’s pretty simple as long as you follow the steps and afterwards you can even install the Google apps package if that’s your thing. Just mind the 1 GB RAM and 8 GB of storage on the Echo Show 8. In the case of [Jeff] he mostly replicated the home automation and entertainment features of Amazon’s FireOS with far less locked-down alternatives like Home Assistant.

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Making The Fastest LEGO Technic Air-Powered Engine

January 1, 2026 by Maya Posch 1 Comment

Just because LEGO Technic is technically a toy doesn’t mean that you cannot do solid engineering with it, like building air-powered engines. After first building a simple air-powered piston engine, this time around [Jamie’s Brick Jams] sought to not only optimize the engine, but also build a clutch and something to power with said engine.

The four-piston design in radial configuration. (Credit: Jamie's Brick Jams, YouTube) — The four-piston design in radial configuration.

The piston head is one of the handful of 3D printed parts, with the new design featuring twin rubber o-rings as a seal instead of a single big one as in the old design. This incidentally matches the multiple seal rings on an internal combustion engine’s pistons, probably for similar blow-by related reasons. The air hose diameter was also increased from 2 to 3 mm to give the engine a larger volume of air to work with, which along with a new flywheel gave a lot more torque. Next the piston rod length was optimized.

The final radial 4-piston engine turns out to work pretty well, with the clutch engaging smoothly. This was used to drive a DIY generator that turned out to produce about 3 Watt of usable power in its final configuration at 6 V, though it’s admittedly a rather crude generator that could be further optimized. When trying a twin-piston configuration with the highest air pressure before air hoses began to pop off, it hit a dizzying 14,600 RPM.

These aren’t half bad results for some LEGO Technic together with some 3D printed bits, rubber o-rings and some lube.

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Putting A Cheapo 1800W DC-DC Boost Converter To The Test

January 1, 2026 by Maya Posch 15 Comments

These days ready-to-use DC-DC converters are everywhere, with some of the cheaper ones even being safe to use without an immediate risk to life and limb(s). This piques one’s curiosity when browsing various online shopping platforms that are quite literally flooded with e.g. QS-4884CCCV-1800W clones of a DC-DC boost converter. Do they really manage 1800 Watt even without active cooling? Are they perhaps a good deal? These were some of the questions that [Josh] over at the [Signal Drift] channel set out to answer.

The only real ‘datasheet’ for this module seems to come courtesy of a Floridian company who also calls it the 36843-PS, but it features specifications that are repeated across store listings so it might as well by the official ‘datasheet’. This module is marketed as being designed for the charging of lead-acid and similar batteries, including the boosting of PV solar panel outputs, though you’d really want to use an MPPT charger for that.

With this use case in mind, it’s probably no surprise to see on the oscilloscope shots under load that it has a tragic 100 kHz switching frequency and a peak-to-peak noise on the output of somewhere between 1-7 VDC depending on the load. Clearly this output voltage was not meant for delicate electronics.

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Jon Peddie’s The Graphics Chip Chronicles On Graphics Controller History

January 1, 2026 by Maya Posch 17 Comments

Using computers that feature a high-resolution, full-color graphical interface is commonplace today, but it took a lot of effort and ingenuity to get to this point. This long history is the topic of [Dr. Jon Peddie]’s article series called The Graphics Chip Chronicles. In the first of eight volumes, the early days of the NEC µPD7220 and the burgeoning IBM PC.

Texas Instruments TMS34020 (Source: Wikimedia)

These are just brief overviews of these particular chips, of course, with a lot more detail to be found when you go digging. Details such as the NEC µPD7220 being the graphics chip in Japan’s PC-9800 series of computers which are famous for the amazingly creative art and games that this chip enabled.

While the average Hackaday reader is likely familiar with the IBM PC side of things, Texas Instruments’ graphics controllers, including the very interesting TMS34010 and successor TMS34020 which can be called the first proper graphical processing units, or GPUs, effectively a CPU with graphics-specific instructions.

Although it’s tempting to see computer graphics as a direct line from the days of monochrome graphic controllers to what we have today in our PCs, there were a lot of companies and countless talented individuals involved, including companies who built clones that would go on to set new standards. If you’re into reading through a few years worth of computer history articles by someone who has been in the industry for even longer, it’s definitely worth a read.

Thanks to [JohnS_AZ] for the tip.

Top image: NEC µPD7220 by Drahtlos – Own work, CC BY-SA 4.0)

Virus-Based Thermoresponsive Separation Of Rare-Earth Elements

December 31, 2025 by Maya Posch 9 Comments

Although rare-earth elements (REEs) are not very rare, their recovery and purification is very cumbersome, with no significant concentrations that would help with mining. This does contribute to limiting their availability, but there might be more efficient ways to recover these REEs. One such method involves the use of a bacteriophage that has been genetically modified to bind to specific REEs and release them based on thermal conditions.

The primary research article in Nano Letters is sadly paywalled, but the supporting information PDF gives some details. We can also look at the preceding article (full PDF) by [Inseok Chae] et al. in Nano Letters from 2024, in which they cover the binding part using a lanthanide-binding peptide (LBP) that was adapted from Methylobacterium extorquens.

With the new research an elastin-like peptide (ELP) was added that has thermoresponsive responsive properties, allowing the triggering of coacervation after the phages have had some time in the aqueous REE containing solution. The resulting slurry makes it fairly easy to separate the phages from the collected REE ions, with the phages ready for another cycle afterwards. Creating more of these modified phages is also straightforward, with the papers showing the infecting of E. coli to multiply the phages.

Whether the recovery rate and ability to scale makes it an economically feasible method of REE recovery remains to be seen, but it’s definitely another fascinating use of existing biology for new purposes.

Escaping The Linux Networking Stack At Cloudflare

December 31, 2025 by Maya Posch 2 Comments

Courtesy of the complex routing and network configurations that Cloudflare uses, their engineers like to push the Linux network stack to its limits and ideally beyond. In a blog article [Chris Branch] details how they ran into limitations while expanding their use of soft-unicast functionality that fits with their extensive use of anycast to push as much redundancy onto the external network as possible.

The particular issue that they ran into had to do with the Netfilter connection tracking (conntrack) module and the Linux socket subsystem when you use packet rewriting. For soft-unicast it is important that multiple processes are aware of the same connection, yet due to how Linux works this made it impossible to use packet rewriting. Instead they had to use a local proxy initially, but this creates overhead.

To work around this the solution appeared to be to abuse the TCP_REPAIR socket option in Linux, which normally exists to e.g. migrate VM network connections. This enables one to describe the entire socket connection state, thus ‘repairing’ it. Combined with TCP Fast Open to skip the whole handshake bit with a TFO ‘cookie’. This still left a few more issues to fix, with an early demux providing a potential solution.

Ironically, ultimately it was decided to not break the Linux networking stack that much and stick with the much less complicated local proxy to terminate TCP connections and redirect traffic to a local socket. Unfortunately escaping the Linux networking stack isn’t that straightforward.