Lithium-Ion Batteries: WHY They Demand Respect

This summer, we saw the WHY (What Hackers Yearn) event happen in Netherlands, of course, with a badge to match. Many badges these days embrace the QWERTY computer aesthetic, which I’m personally genuinely happy about. This one used 18650 batteries for power, in a dual parallel cell configuration… Oh snap, that’s my favourite LiIon cell in my favourite configuration, too! Surely, nothing bad could happen?

Whoops. That one almost caught me by surprise, I have to shamefully admit. I just genuinely love 18650 cells, in all glory they bring to hardware hacking, and my excitement must’ve blindsided me. They’re the closest possible entity to a “LiIon battery module”, surprisingly easy to find in most corners of this planet, cheap to acquire in large quantities, easy to interface to your projects, and packing a huge amount of power. It’s a perfect cell for many applications I and many other hackers hold dear.

Sadly, the 18650 cells were a bad choice for the WHY badge, for multiple reasons at once. If you’re considering building a 18650-based project, or even a product, let me show you what exactly made these cells a bad fit, and how you might be able to work around those limitations on your own journey. There’s plenty of technical factors, but I will tell you about the social factors, because these create the real dealbreaker here. Continue reading “Lithium-Ion Batteries: WHY They Demand Respect”

The Supercon 2025 Badge Is Built To Be Customized

For anyone who’s joined us for previous years, you’ll know that badge hacking and modification are core to the Hackaday Supercon experience. While you’re of course free to leave the badge completely stock, we encourage attendees to tear it apart, learn how it works, and (hopefully) rebuild it into something unique. There are even prizes for the best hacks.

As such, every decision about the badge’s hardware and software is made with hackability in mind. It’s why we always try to add an expansion port to the badge and, in recent years, have leaned into MicroPython to make it easier for attendees to modify the code.

But one thing that’s been largely missing in previous badges is aesthetic customization. Sure, you could strip out the firmware and write something entirely new, or hang some oddball peripheral off the side of the thing, but ultimately it still looked like the badge we gave you at the door. That’s because, at the end of the day, the badges are just PCBs. Short of designing your own enclosure (which has certainly been done), every badge looks the same. That is, until now.

Continue reading “The Supercon 2025 Badge Is Built To Be Customized”

Decorate Your Neck With The First Z80 Badge

Over the years, we’ve brought you many stories of the creative artwork behind electronic event badges, but today we may have a first for you. [Spencer] thinks nobody before him has made a badge powered by a Z80, and we believe he may be right. He’s the originator of the RC2014 Z80-based retrocomputer, and the badge in question comes from the recent RC2014 Assembly.

Fulfilling the function of something you can write your name on is a PCB shaped like an RC2014 module, with LEDs on all the signal lines. It could almost function as a crude logic analyser for the system, were the clock speed not far too high to see anything. To fix this, [Spencer]’s badge packs a single-board RC2014 Micro with a specially slow clock, and Z80 code to step through all memory addresses, resulting in a fine set of blinkenlights.

Thus was created the first Z80-based event badge, and we’re wondering whether or not it will be the last. If you’re curious what this RC2014 thing is about, we reviewed the RC2014 Micro when it came out.

The WHY 2025 Badge And Its 18650s

The largest European hacker camp this year was in the Netherlands —  What Hackers Yearn (WHY) 2025 is the latest in the long-running series of four-yearly events from that country, and 2025 saw a move from the Flevoland site used by SHA2017 and MCH2021, back to just north of Alkmaar in Noord-Holland, where the OHM2013 event took place. WHY has found itself making the news in the Dutch technical media for all the wrong reasons over the last few days, after serious concerns were raised about the fire safety of its badge.

The cell supplied with a WHY 2025 badge, with very clear fire safety warning
This is the cell supplied with the WHY badge, complete with manufacturer’s warning.

The concerns were raised from the RevSpace hackerspace in Leidschendam, and centre around the design of the battery power traces on the PCB between the battery holders and the power supply circuitry. Because the 18650 cells supplied with that badge lack any protection circuitry, bridging the power traces could be a fire risk.

In short: their report names the cell holders as having tags too large for their pads on the PCB, a too-tight gap between positive and negative battery traces, protected only by soldermask, and the inadequacy of the badge’s short circuit protection. In the event that metal shorted these battery tags, or wore through the soldermask, the batteries would be effectively shorted, and traces or components could get dangerously hot.

The WHY organizers have responded with a printed disclaimer leaflet warning against misuse of the cells, and added a last-minute epoxy coating to the boards to offer additional protection. Some people are 3D-printing cases, which should also help reduce the risk of short-circuiting due to foreign metal objects. Using an external powerbank with short-circuit protection instead of the cells would solve the problem as well. Meanwhile a group of hackers collecting aid for Ukraine are accepting the batteries as donations.

It’s understood that sometimes bugs find their way into any project, and in that an event badge is no exception. In this particular case, the original Dutch badge team resigned en masse at the start of the year following a disagreement with the  WHY2025 organizers, so this badge has been a particularly hurried production. Either way, we are fortunate that the issue was spotted, and conference organizers took action before any regrettable incidents occurred.

Two For The Price Of One: BornHack 2024 And 2025 Badges

BornHack is a week-long summer hacker camp in a forest on the Danish island of Fyn, that consistently delivers a very pleasant experience for those prepared to make the journey. This year’s version was the tenth iteration of the camp and it finished a week ago, and having returned exhausted and dried my camping gear after a Biblical rainstorm on the last day, it’s time to take a look at the badges. In case you are surprised by the plural, indeed, this event had not one badge but two. Last year’s badge suffered some logistical issues and arrived too late for the camp, so as a special treat it was there alongside the 2025 badge for holders of BornHack 2024 tickets. So without further ado, it’s time to open the pack for Hackaday and see what fun awaits us. Continue reading “Two For The Price Of One: BornHack 2024 And 2025 Badges”

Plenty Of LEDs And Useful Too: The 2025 DORS/CLUC Badge

It’s always nice to see new developments in the world of electronic badges, and while there are events and badge teams pushing the technological envelope there’s still plenty of scope for innovation without too many exotic parts. This year’s DORS/CLUC open source conference in Croatia has just such a badge, with a large alphanumeric LED display as well as USB and an NFC reader. During the conference it displayed the user’s name and could be used in an NFC-based game, but it’s also designed to be used as a general purpose notification device afterwards.

The write-up is familiar to anyone who has been involved with badge production, a tale of long soldering sessions as missing components had to be added later, and of last minute firmware flashing. The heart of the machine is an STM32L073, with an IS31FL3731 LED matrix driver chip and an ST25R3916 for the NFC. All the files can be found in a GitLab repo, and there’s a video below the break showing it all in action.

Continue reading “Plenty Of LEDs And Useful Too: The 2025 DORS/CLUC Badge”

Clever PCBs Straighten Out The Supercon SAO Badge

When we decided that Simple Add-Ons (SAOs) would be the focus of Supercon 2024, it was clear the badge would need to feature more than just one or two of the requisite connectors. We finally settled on six ports, but figuring out the geometry of getting all those ports on the badge in such a way that the SAOs wouldn’t hit each other was a bit tricky. In early concept drawings the badge was just a big rectangle with the ports along the top, but it was too ugly.

In the end we went with a somewhat organic design — an electronic “flower” with the radially arranged SAOs forming the petals, but this meant that that none of the SAOs were in the traditional vertical orientation. Luckily, [Adrian Studer] designed a couple of PCBs that not only resolve this issue, but add a seventh SAO port for good measure.

In the project repository you’ll find two PCB designs. The first, “SAO Up” is essentially a little arm that turns the SAO port 90 degrees. This doesn’t exactly get them vertical, in fact, whether or not the new orientation is actually an improvement for the top two SAOs is perhaps debatable. But it definitely helps on the lower SAOs, which are essentially upside down in their original configuration.

The real star of the show is “SAO Bridge”, a wavy board that connects across the two midline SAO ports on the Supercon badge and turns it into a set of three (nearly) horizontal connectors across the front. The center port is particularly helpful in that it gives you a place to put unusually wide SAOs.

As a reminder the Supercon SAO badge, and the winners of the 2024 SAO Contest, will be making the trip across the pond for Hackaday Europe in just a few months. That means you’ve still got plenty of time to have a few of these CERN-OHL-P licensed boards made up.