Yesterday, Isar Aerospace secured its place in the history books when the upper stage of their Spectrum rocket put a payload of CubeSats into low Earth orbit (LEO). Not only does this make them the first European company to achieve such a feat, but it also marks the first time a booster departing from continental Europe has reached orbit. Not bad for a second attempt.

Standing 28 meters (92 feet) tall, the two-stage Spectrum rocket is just shy of half the size of the SpaceX Falcon 9 and designed to put a maximum of 1,000 kilograms (2,200 pounds) into LEO and 700 kg (1,500 lb) into the Sun-synchronous orbits used by Earth observation satellites. That puts its performance considerably ahead of other commercial launchers such as Rocket Lab’s Electron. Although the booster is not reusable, Isar Aerospace has stated they’re targeting a respectable launch cost of €10,000 ($11,700) per kilogram. The German company notes there are several more Spectrum vehicles currently in production, and when their new factory is operational, they’ll have the capacity to produce up to 40 of them each year.

In other European space news, BepiColombo has now entered what the European Space Agency (ESA) is calling the “arrival phase” of its nearly decade-long journey to Mercury. On Thursday, the spacecraft jettisoned its ion propulsion module as it had achieved the necessary trajectory and velocity to be captured by the planet’s gravitational field when it swoops by in November.

Launched in 2018, the BepiColombo mission is actually carrying two separate craft: the ESA’s Mercury Planetary Orbiter and the Mercury Magnetospheric Orbiter from Japan. After the two separate from each other in December, they will operate independently to study their respective aspects of the solar system’s innermost planet for the next year, although, as is often the case for missions like this, an extension is always possible if things are still going well at that point.

On the subject of hardware outliving its original design lifetime, an active community of hackers has done a fantastic job of keeping the Spotify Car Thing up and running after the company officially pulled the plug on it just two years after its 2022 release. They’ve got a full Linux distribution running on it featuring a slick UI that can launch apps, check the weather, tap into Home Assistant, and of course, play music. The community is currently running a contest with cash prizes to spur on development of new open source software for the liberated Car Thing, and we’re eager to see what comes of it.

Speaking of keeping things open, the Free Software Foundation (FSF) has joined Bluesky — but they aren’t exactly thrilled with it. Being federated and largely comprised of free and open-source software, the FSF admits that Bluesky is the lesser evil when compared to something like X or Facebook. But they still can’t recommend others join the service, as the actual signup process requires your browser to run non-free JavaScript code.

One may wonder why the FSF would join Bluesky if they can’t recommend the service to others, and the answer is simply because they want to get the word out to a wider audience. While the FSF already operates an account on Mastodon, there’s a good chance that anyone who’s willingly regularly using said platform doesn’t need any additional convincing when it comes to the evils of proprietary software.

This is as good a time as any to point out that Hackaday is on Bluesky and Mastodon as well, and unlike the FSF, we’re also on Facebook, although the automatic sharing of new posts hasn’t worked for quite some time and honestly we can’t be bothered to figure out why. For our readers with a particular aversion to grass, we’ve even got an official IRC channel on libera.chat where you and nearly 50 others can feel superior to the thousands of immoral heathens that have joined our Discord server.

Finally, it’s been 50 years since the introduction of the ColorChecker — that little card with 24 blocks of colors that’s placed in the frame of a picture or video to provide a visual reference point. In honor of the milestone, Calibrite has put together a timeline that walks you through its history, starting with its inception in the 1976 paper “A Color-Rendition Chart” by C.S. McCamy, H. Marcus, and J.G. Davidson and running up to how the handy tool evolved for the digital age.

There are plenty of facts and trivia about the ColorChecker that you can bring up the next time you want to impress a photographer, and we especially appreciated the breakdown of what each of the original 24 colors was meant to represent.

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If you find yourself lost in the woods or adrift in the ocean, a GPS-enabled Personal Locator Beacon (PLB) is certainly a handy thing to have as it will pinpoint your location for rescuers. The one [Steve Jernigan] has is relatively affordable considering it might save your life one day, but it turns out that replacement batteries for the unit are extremely expensive and hard to come by because the manufacturer would rather you send the unit back to them for refurbishment. So naturally, he took it apart and figured out how to do it himself.

His DIY battery pack consists of a small custom PCB and pair of off-the-shelf 6 volt lithium manganese dioxide cells in a 3D printed enclosure that slots into the rear of the McMurdo PLB. In assembly video below, [Steve] shows how the pack goes together and demonstrates the use of a two-part potting compound in an effort to keep the elements at bay.

Before anyone says it — putting a homemade battery pack into a device which one day might be the only thing standing between you and death is probably not a great idea. [Steve] mentions in the description of this project that this is meant for backup purposes, and that you should really spring for a legitimate battery if there’s a chance you might actually need to be rescued at some point.

If you’re interested in battery pack hacking that doesn’t potentially risk life and limb, fixing the one that came with your cordless drill might be a better project to start with.

While the Citroën logo they project onto the pavement looks great, [OrangeTungsten] wasn’t thrilled with how their door-mounted projectors actually functioned. The mechanism for detecting when they should kick on was a bit too clever for its own good, and needed to be simplified a bit. Luckily for us, the process was meticulously documented for anyone else who might find themselves in a similar situation.

Originally, the projector detected when it should turn on by sensing the presence of a tiny magnet using a Hall effect sensor. There are certainly some advantages to this approach, but in practice, [OrangeTungsten] says the retrofitted magnet would keep falling off and leaving the projector inoperative. The fix was simple enough: figure out how the circuit worked, pull out the Hall effect sensor, and replace it with a simple button that would physically make contact with the door frame.

It’s not a terribly complex fix, but it’s a clever solution and well documented, and that goes pretty far around these parts. We were also interested in this one because an examination of the electronics inside the projector uncovered a 8-pin microcontroller — the sole purpose of which would appear to be polling the Hall effect sensor and using its status to throw a transistor which in turn powers the LED.

It’s hard to believe that whoever designed this gadget couldn’t figure out how to turn an LED on and off without a MCU, but we’re living in strange times. We assume there’s some kind of justification for this, such as some flashing or fading effects, but [OrangeTungsten] never mentions the things doing anything more complex than simply turning on and off.

Whatever the rationale was behind the original design of these projectors, the important thing is that the application of some hardware from the parts bin got them up and working again, which is something we never get tired of seeing.

The big news today is, of course, the successful launch and deployment of NASA’s Nancy Grace Roman Space Telescope earlier this morning. The space agency’s latest observatory lifted off at 7:26 AM Eastern from Launch Complex 39A at Kennedy Space Center aboard a SpaceX Falcon Heavy, and by 8:00 AM it was separated from the rocket’s upper stage and flying on its own.

While the sound and fury of launch is exciting, it’s just the beginning of the journey for Roman. It will take several months for the spacecraft to complete its roughly 1.5 million-kilometer trek out to Earth’s second Lagrange point (L2), where it will set up shop near — in cosmic terms, anyway — the James Webb Space Telescope (JWST). Along the way, it will switch on and test various systems and components, with its primary 300 megapixel infrared camera scheduled to power up in three weeks or so.

There’s a lot to cover about the Roman Space Telescope. Built from spy satellite spare parts donated by the National Reconnaissance Office and featuring a field of view 100 times greater than that of Hubble, its launch is widely considered to be one of the most important scientific milestones of the decade. We’ll be bringing you more about the past, present, and future of this flagship mission as it progresses.

From real space missions to virtual ones, this week the developers of EVE Online announced that 2.4 million lines of code that keep the massively multiplayer online role-playing game running would finally be making the switch to Python 3. Given the immense complexity of the codebase, it’s been stuck at Python 2.7 since their last overhaul back in 2010, a situation which has become increasingly difficult to manage as time goes on.

The announcement goes into a surprising amount of depth about the state of Python in EVE. We imagine most players couldn’t care less, but naturally the developers have strong feelings about the situation and perhaps thought it would benefit others in a similar situation to get their thoughts out there.

While there’s certainly an argument to be made that the only justification they really need for making the migration is that 2.7 hit end-of-life back in 2020, the developers explain that the more immediate problem for them was that various tools and libraries they wanted to use were no longer compatible with the Python 2.x series. They also point out hopes that speed improvements made in the latest version of Python will eventually translate into better game performance down the road.

In more terrestrial news, this week the necessary regulatory amendments were passed to make plug-in solar systems legal in the United Kingdom. Assuming the wiring meets the necessary requirements, consumers can pick up the hardware and install it themselves without involving an electrician, although they may still need to contend with landlords and local ordinances that may limit their ability to physically mount the panels. The rules as they stand now allow each residence to have four panels with a total combined output rating of no more than 2,000 watts, although critically, the system is only allowed to generate a maximum of 800 watts at the inverter. As the government and consumers get more comfortable with plug-in solar systems, these numbers will likely increase over time.

Solar isn’t the only area where DIY approaches are moving into the mainstream. This week, Citrix pitched a “different approach to endpoint resiliency”: an isolated Linux-based operating system called UniconOS that users can boot into should the computer’s primary Windows installation become compromised or otherwise inoperable. The idea is that an independent, read-only backup OS kept on its own partition will reduce downtime, since the computer can still be used while IT figures out what the hell happened.

This solution will sound suspiciously familiar to anyone who’s booted a live Linux system from CD/DVD/USB in the last few decades. Try not to keep yourself up all night wondering why you never pitched the idea to some hungry venture capitalists in exchange for a yacht in the Bahamas.

Finally, on the theme of new technology embracing the old ways, we bring you Defrag98, a web reincarnation of Microsoft’s dial-up era Disk Defragmenter tool. While it won’t actually improve the performance of your modern solid-state drive, you may find your own mood boosted by the wave of nostalgia when you see — and hear — the classic tool go to work.

That’s right, not only do the blocks dutifully flip from red to blue just like you remember, but all the while you’ll be treated to the unmistakable whirs and clicks of a spinning hard drive circa the turn of the millennium. Never forget what they took from us.

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We’ll start this week off with some disappointing, though not entirely unexpected, news — the ambitious commercial mission to save NASA’s Neil Gehrels Swift Observatory is officially a bust. The space agency provided an update earlier this week explaining that the attitude control issues with the LINK spacecraft that started a few weeks after it launched will prevent it from being able to safely dock with the Swift Observatory and boost its altitude. As such, the space telescope is now expected to reenter the Earth’s atmosphere and burn up before the end of the year.

Although LINK won’t be able to live up to its name, NASA did say operator Katalyst Space has been given permission to continue with the rendezvous attempt. The two craft won’t actually make contact with each other, but teams on both sides feel there’s lessons to be learned and data to be collected by seeing the orbital dance of these two vehicles play out for as long as possible.

Speaking of hardware that couldn’t quite hit its design goals, TechCrunch is reporting that a class action lawsuit has been filed against Oura by customers that say the company made misleading claims about the sleep-tracking accuracy of their smart rings. Namely, that the rings could somehow detect which stage of sleep the wearer was in with only the pulse and temperature sensors it has onboard.

The complaint argues that sleep stages can only be accurately determined with an electroencephalogram (EEG), and that there’s no way for the ring hardware to actually know what’s happening in the wearer’s brain. For their part Oura has released a statement defending their methodology, and say that the ability of their rings to estimate sleep cycles compares favorably with data collected from clinical sleep studies. It should be interesting to see how this one plays out.

On the subject of products not quite doing what you expected, there’s been a story buzzing around online about a number of computer games failing to work properly on Windows machines that have installed the August system updates. Microsoft has investigated the issue and is currently pointing the finger towards RGB lights as the potential culprit.

On the surface it might sound like some kind of exotic hardware clash or interference, but the actual issue is disappointingly mundane. According to Microsoft, the August update fiddles with a system component that the software which drives some of these lights ties into, namely inpoutx64. As a quick fix they’ve provided some instructions on keys that can be modified in the Windows Registry to prevent the conflict, but it sounds like such gefingerpoken und mittengrabben may prevent the blinkenlights from performing their critical function.

Finally, we’ll end this week with an update on the ASCII CITY project that’s been making the rounds online. For those who haven’t seen it yet, this is 3D engine implemented in a single HTML file that renders a cyberpunk 3D city for players to wander around in. The latest version brings many new features to the non-game, notably the ability to enter the various buildings scattered throughout the world.

Previously we could only admire this virtual world from afar. But now that developer Grow Now! Games has released a playable prototype, you can transport yourself into this new digital frontier like in Tron.

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In this week’s episode, Hackaday Editors Elliot Williams and Tom Nardi start things off by getting excited about the recently announced 2026 Retrocomputing Challenge. From there the conversation will cover efforts to improve desktop 3D printing with lasers, an expensive grill with an ESP32 controller and an open source firmware, open source tools underground, and some impressive techniques to squeeze a bit more utility out of the common QR code.

You’ll also hear about turning PVC pipes into flat stock, old school Radio Shack electronic kits, and VR soldering demos. Stick around to the end of the episode learn about the latest developments in over-the-counter hearing aids and the 1-bit CPU that’s enjoying an unexpected fandom nearly 50 years after its release.

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

Direct download in DRM-free MP3.

Episode 383 Show Notes:

Mailbag:

• Alexander wrote in praise of buying ultrasonic knife guts. Donald Papp wrote up his experience with a hacked dental tool a few years back. Now you can get it over the counter.
• Joey wrote in asking if we can add video/visuals to the Podcast. We complain about how difficult that would be.  :)
• Mailbag still needs intro/outro music. Anyone want to whip something up? Send it to mailbag@hackaday.com.

News:

• Announcing The 2026 Hackaday Retrocomputing Challenge
• Using The Famicom Network System In 2026

Interesting Hacks of the Week:

• Laser Layers For (Almost) Isotropicly Strong Prints
  • 3D Print Smoothing, With Lasers
  • More On Wave Overhangs For 3D Printing
• Reverse Engineered Grill Controller Gets Open Firmware
• Hackaday Europe 2026: Open Source Hardware Goes Underground, Literally
  • GitHub – furbrain/STIC · GitHub
• Building Custom Backyard Solar Lights
  • PVC Pipe Transformed Into Handy Tool Box
• Compress Links For Optimal QR Codes
  • http://ha.mr#2)22
  • Store Tunes On Paper And Stream Them Over LoRA
• Radio Shack Toy Returns To Life

Quick Hacks:

• Elliot’s Picks:
  • Joy-Cons Plus WiiMotes Make For Switch 2 Wii-Cons
  • So, You Want To Fix An Old Camera
  • Watch Soldering Up Close And From Any Angle, In VR
  • May This Balloon Banjo Resonate With You
• Tom’s Picks:
  • Snooping Flume Water Monitor Data On The Wire
  • Smarting Up A Doorbell With Zigbee
  • Scanning For Lifesigns With ESP32 And Raspberry Pi

Can’t-Miss Articles:

• Smartphones And The Next Generation Of Hearing Aids
• Hackaday Europe 2026: The 1-Bit CPU That Ran Factories
  • Building An Industrial Control Unit With An Industrial Control Unit
  • A one-bit processor explained: reverse-engineering the vintage MC14500B
  • WDR-1-Bit-Computer
  • Too Cool For 8-bit Retro? Try 1-bit Gaming

Your desk or bench is a work area, so why not make it look the part? That’s the idea behind the miniature blinking traffic barrels that [Glen Akins] recently put together. Of course, just a single blinking light doesn’t really sell the idea of a busy construction zone, so he spent a somewhat surprising amount of time and effort optimizing the design for small-scale production.

The end result is a fascinating write-up that dives into the design decisions [Glen] made. Every aspect of this project, from the overhang of the “handle” on the 3D printed barrel to the number of passive components on the PCB was carefully considered. Critics may say [Glen] put too much thought into something that didn’t need to be so complex, but projects like these are an excellent way to keep your skills sharp — there’s no such thing as practicing too much.

Starting with the design of the barrel itself, we appreciate that [Glen] kept the capabilities of his desktop 3D printer in mind. By breaking the design up into multiple pieces and avoiding overly steep angles, he produced a design that prints cleanly without the need for support material. His step-by-step documentation and screenshots also serve as a great introduction to designing parts in Fusion if that’s something you’re interested in.

From there, things switch over to the electronics. Some in the audience will bemoan that he’s using a PIC12F1612 microcontroller to blink a single LED instead of a 555, but [Glen] brought the receipts on this one. Not only does the PIC offer more flexibility in terms of getting the blinking to look the way he wants, but it requires fewer passive components on the board and is considerably more energy efficient than the iconic timer IC. Even if you ignore all the other advantages, he calculates that going with a 555 would have cut the battery life of the finished product by approximately 15%.

This is one of those projects that’s difficult to summarize in such a terse format, as every time you think the write-up must be about over it takes a new turn on you. We were mildly bemused when the second iteration of the PCB popped up, but by the time he introduced the custom programming adapter board, we knew [Glen] wasn’t messing around.

Unsurprisingly, this isn’t the first time we’ve seen [Glen]’s handiwork. You may recall seeing his RP2040-powered sound board earlier this year, but his name has been popping up on these pages for more than a decade now.

If you don’t actually need one, you’d be forgiven for thinking a hearing aid just makes everything louder for the wearer. Especially since there are plenty of shady products out there which will do exactly that for just four easy payments of $29.99. But the reality is considerably more complex, as a proper hearing aid needs to be capable of selectively enhancing certain frequencies while squashing down others.

The technical challenges involved in pulling that off in a device small enough to fit inside the human ear and run off of a tiny battery are considerable — and while there’s undoubtedly been some degree of artificial price inflation going on over the years, there’s a reason proper hearing aids have been so much more expensive than their “As Seen on TV” counterparts. These same challenges are also why DIY and open source hardware hearing aids have struggled to gain much traction.

But over the last few years the situation has changed. In 2022 the United States Food and Drug Administration (FDA) established the framework by which hearing aids could be sold over the counter (OTC). Although they’re generally less capable than their prescription counterparts and not suitable for individuals with profound hearing loss, the wide commercial availability of OTC hearing aids has kicked off a competition between manufacturers to deliver more affordable devices.

That competition entered a new phase earlier this month when the FDA granted approval for Samsung’s Galaxy Earbuds to fall under the same category. This follows a similar decision made about Apple’s AirPods back in 2024. The two biggest players in the smartphone market being able to offer their earbuds as OTC hearing aids represents a unique value proposition. Not only are they priced for mass market consumption, but many individuals who would be interested in purchasing an OTC hearing aid will already own them and need only to enable the feature with a software update.

Given how different the situation is today than even just five years ago it’s worth asking just what qualifies as a over-the-counter hearing aid, and how the shifting definition of these devices can inform the community’s efforts to develop open hardware solutions.

What is a Hearing Aid, Anyway?

We’ve already covered what a hearing aid isn’t, but before we go too much further it’s a good idea to clarify what exactly a hearing aid does in comparison to a simple audio amplifier, which in the industry are officially known as Personal Sound Amplification Products (PSAPs). This is a topic we’ve touched on previously here at Hackaday, but the short version is that since the 1980s or so, the frequencies that a hearing aid amplifies have been tailored to match the specific auditory deficiencies of the wearer.

Traditionally, getting a hearing aid prescribed would require going to an audiologist and getting an audiogram. This chart plots the results of a hearing test, and shows how well the patient can hear various frequencies. With this data, it’s possible to quantify the severity of a patient’s hearing loss and determine where a hearing aid could improve the situation. This information could then be programmed into a hearing aid to provide a bespoke amplification profile that takes into account the needs of the wearer.

It’s worth noting that this is only in the context of relatively modern digital hearing aids, essentially those created after the introduction of solid state electronics. Prior to that point, hearing aids were closer to what we would now consider PSAPs and amplified incoming audio indiscriminately.

Defining a Middle Ground

With this in mind, the primary difference between a prescription hearing aid and an OTC model is that the audiologist is cut out of the loop. That means there’s no audiogram, and in turn no data to program the hearing aid’s filters with. The specifics of this does vary from model to model, and both Samsung and Apple offer some basic audio testing tools that can help the user fine-tune their experience. But at this point, no OTC hearing aid product is capable of diagnosing the wearer’s hearing to the same level as a comprehensive hearing test performed by an audiologist

That being the case, it might seem like an OTC hearing aid is just a PSAP. But in their ruling, the FDA established the formal requirements for a device that falls somewhere in the middle. The full document, Medical Devices; Ear, Nose, and Throat Devices; Establishing Over-the-Counter Hearing Aids, comes in at around 200 pages if you’re looking for some light reading.

Fortunately, the agency provides a boiled-down list of what features a device must have to meet the definition of an OTC hearing aid. Some of the requirements have to do with the packaging and marketing of the product, which of course are important for a medical device, but it’s the technical parameters that we’re interested in.

The FDA specifies that all OTC hearing aids must use air-conduction, that is, operate with a speaker inserted into the ear canal. The alternative would be bone conduction, which is generally used in cases with more profound hearing loss. The devices must also allow users to adjust, at least to some degree, the output to match their specific needs.

The intention with this second requirement goes deeper than a simple volume control as you’d have in an PSAP. In lieu of the sort of tailored output a prescription hearing aid would offer, the OTC device can offer a selection of pre-defined audio filter profiles which the user could flip through. At the risk of oversimplifying things, it’s a bit like the audio presets for different genres of music that modern headphones and earbuds usually offer in that the user can cycle through different profiles to find what best matches the current environment.

When combined with the acknowledgement that OTC hearing aids can utilize wireless technology to communicate with another device, it’s not hard to see how the smartphone fits into the equation. While a stand-alone device is capable of meeting the requirements necessary for OTC hearing aid classification, being able to connect to the user’s phone to easily switch between audio profiles on the fly makes for a greatly improved user experience. Additionally, by playing tones through the earbuds, software on the phone can perform a hearing test on the user — the results of which can be used to fine-tune the output beyond what’s possible with simple presets.

Hackers, Take Note

Of course, anyone looking to build an open source hearing aid probably isn’t looking for FDA approval. The goal is likely to make the technology cheaper and more accessible, especially in areas where getting a commercially produced hearing aid may be difficult. As such, the new over-the-counter classification may not seem terribly important for folks like us.

But that doesn’t mean we can’t pick up some tips from what companies like Samsung, Apple, and Jabra are doing. By bringing the user’s smartphone into the mix, they have made hearing aids more accessible and easier to operate. Instead of trying to pack all of the functionality directly into the wearable, using a smartphone to do some of that heavy lifting opens up a lot of new possibilities. There are naturally trade-offs when switching a hardware problem for a software one, especially when dealing with mobile operating systems, but it may be a compromise worth making if it means getting this sort of assistive tech to more people that need it.

These days open source is everywhere, and frankly, we couldn’t be happier about it. But even with as prevalent as open software and hardware has become, we still occasionally hear about a project that takes the concept somewhere unexpected. Which is precisely why we were so eager to hear more about the fascinating work [Phil Underwood] has been doing.

In his talk Open Source Caving: 20 Years of Making Cave Mapping Tools at Hackaday Europe 2026, [Phil] takes us through a series of progressively more advanced open hardware devices that he’s designed to increase the speed and accuracy of underground mapping efforts. Along the way, he’s learned a number of valuable lessons about designing hardware that’s robust enough to handle the uniquely challenging environment underground while still being accessible enough for a hobbyist to build and use.

Improving on the Old School

It’s not much of a stretch to assume that most Hackaday readers haven’t spent a lot of time crawling through underground passages, and as such, may not be immediately aware of how one begins to map a cave in the first place. Helpfully [Phil] starts off his talk by explaining the traditional process — which generally involves a compass, an inclinometer, a tape measure, and plenty of intricate notes.

Once you’ve collected all that data and successfully returned to the surface with it, you can plug it into software and create a three dimensional map of the cave. Sprinkle in some surface topography, and you’ve got a pretty slick overview of whats above and below ground.

Like so many other cavers, [Phil] wanted a way to make that first half of the process a bit less tedious. He imagined an electronic device that could take at least some of the necessary measurements for him, but was limited by the technology and at-home production capabilities available to hobbyists in the early 2000s. There was also the cave environment to contend with: any piece of equipment used in a cave not only needs to be able to handle the dusty and cramped conditions,  but must be reasonable shock resistant. If that wasn’t tricky enough, there’s also a non-zero chance that it will need to spend some amount of time underwater.

Incremental Improvements

The first-generation of [Phil]’s surveying device. Undaunted, [Phil] put his first electronic caving aid together in 2008. Inside the off-the-shelf Radio Shack enclosure was an 8-bit PIC18LF2550, a dot-matrix display, an accelerometer, and a magnetometer. The data from the two sensors could be used to determine the heading and angle that the device was being held at, and while it still required the operator to manually take a distance measurement along that vector, having two-thirds of the information already computed saved considerable time and effort during surveys.

The next big technological leap came in 2020 — not just in terms of the device itself, but in the tools [Phil] had access to. This new device utilized a 32-bit microcontroller, a 3D printed frame, and included a laser rangefinder.

Thanks to the the increased computational capabilities offered by the modern MCU, more of the necessary calculations could be done on the device itself, which further sped up the surveying process. But [Phil] notes that the data from the laser module wasn’t always reliable, and keeping the more complex device protected from the elements introduced new challenges.

Now evolving at a faster clip, by 2023 [Phil] had improved on the design with a better integrated 3D printed case, custom silicone buttons, and a more polished user interface. At this point, he also switched over to writing the device’s firmware in CircuitPython. The lower bar of entry compared to C seemed to better resonate with those in the community, and consequently [Phil] started seeing more code contributions from outsiders.

New Dimension, New Challenges

By this point [Phil] had a pretty solid handheld device to assist in performing cave surveys, but the end result was ultimately the same as if the measurements had been taken manually. Each successive generation of the hardware made the process of gathering spatial data faster and less cumbersome, but didn’t meaningfully improve the final product.

Creating higher fidelity maps would require more data and the computational power to churn through it, which is why the latest generation of [Phil]’s hardware utilizes a Raspberry Pi 5 Compute Module and a pair of low-light cameras to perform photogrammetry. When combined with the heading and angle data, this produces a textured 3D model of the inside of the cave with minimal manual effort on the part of the user.

While this latest generation of hardware is undeniably more capable than what came before it, there’s an argument to be made that it also takes a step backwards in some respects. The cameras represent a physical weak point, and [Phil] says he’s still working on an approach to more adequately handle the increased power requirements of the Pi 5 Compute Module compared to the microcontrollers used in his earlier devices. But just as with the rest of the problems faced over the last two decades, these issues will likely be resolved in time as well.

In the end, this incremental approach to hardware development may be the most valuable lesson to take away from [Phil Underwood]’s talk. It’s a safe bet that the vast majority of those who view this presentation will never find themselves exploring an underground cave system, much less mapping one. But that doesn’t mean they can’t learn from his practical and methodical approach to building the right tool for the job.