2025-10-24 07:00:37
There was a time, long ago, when passenger vehicles used to be much simpler than they are today. There were many downsides of this era, safety chief among them, but there were some perks as well. They were in general cheaper to own and maintain, and plenty could be worked on with simple tools. There’s perhaps no easier car to work on than an air-cooled Volkswagen, either, but for all its simplicity there are a number of modern features owners add to help them with these antiques. [Pegor] has created his own custom engine head temperature monitor for these vehicles.
As one could imagine with an air-cooled engine, keeping an eye on the engine temperature is critical to ensuring their longevity but the original designs omitted this feature. There are some off-the-shelf aftermarket solutions but this custom version has a few extra features that others don’t. It’s based on a ATMega32u4 microcontroller and will work with any K-type thermocouple, and thanks to its open nature can use a wide array of displays. [Pegor] chose one to blend in with the rest of the instrumentation on this classic VW. The largest issue that needed to be sorted out was around grounding, but a DC-DC converter created an isolated power supply for the microcontroller, allowing the thermocouple to be bonded to the grounded engine without disrupting operation of the microcontroller.
The finished product looks excellent and does indeed blend in to the dashboard more than the off-the-shelf temperature monitor that was in use before. The only thing that is planned for future versions is a way to automatically dim the display when the headlights are on, as [Pegor] finds it a little bright at night. We also enjoy seeing anything that helps these antiques stay on the road more reliably as their modern descendants don’t have any of the charm or engineering of these classics.
2025-10-24 04:00:45
[kcraske] had a simple plan for their clock build. They wanted a digital clock that was inspired by the appearance of an analog one, and they only wanted to use basic logic, with no microprocessors involved. Ultimately, they achieved just that.
Where today you might build a clock based around a microcontroller and a real-time clock module, or by querying a network time server, [kcraske] is doing all the timekeeping in simpler hardware. The clock is based around a bunch of 74-series logic chips, a CD4060 binary counter IC, and a 32.768 KHz crystal, which is easy to divide down to that critical 1 Hz. Time is displayed on the rings of LEDs around the perimeter of the clock—12 LEDs for hours, and 60 each for minutes and seconds. Inside the rings, the ICs that make up the clock are arranged in a pleasant radial configuration.
It’s a nice old-school build that reminds us not everything needs to run at 200 MHz or hook up to the internet to be worthwhile. We’ve featured some other fun old-school clocks of late, too. Meanwhile, if you’re cooking up your own arcane timepieces, we’d love to hear about it on the tipsline.
2025-10-24 02:30:22
One of the hardest parts of a project — assuming it makes it that far — is finishing it up in an aesthetically pleasing manner. As they say, the devil is in the details, wearing Prada. Apparently the devil also has an excellent manicure, because [Tamas Feher] has come up with a way to introduce incredibly detailed decals (down to 0.1 mm) in cheap, repeatable fashion, using a technique borrowed from the local nail salon.
For those who aren’t in to nail art (which, statistically speaking, is likely to be most of you) there is a common “stamping” technique for putting details onto human fingernails. Nail polish is first applied to voids on a stencil-like plate, then picked up by a smooth silicone stamper, which is then pressed against the nail, reproducing the image that was on the stencil. If that’s clear as mud, there’s a quick demo video embedded bellow. There’s a common industrial technique that works the same way, which is actually where [Tamas] got the idea. For nail salons and at-home use, there are a huge variety of these stencils commercially available for nail art, but that doesn’t mean you’re likely to find what you want for your project’s front panel.
[Tamas] points out that by using a resin printer to produce the stencil plate, any arbitrary text or symbol can be used. Your logo, labels, whatever. By printing flat to the build plate, you can take advantage of the full resolution of the resin printer — even an older 2 K model would more than suffice here, while higher res like the new 16 K models become the definition of overkill. The prints go quick, as they don’t need any structural thickness: just enough to hold together coming off of the plate, plus enough extra to hold your designs at a 0.15 mm inset. That doesn’t seem very thick, but remember that this only has to hold enough nail polish to be picked up by the stamper.
[Tamas] cautions you have to work fast, as the thin layer of nail polish picked up by the stamper can dry in seconds. You’ll want plenty of nail polish remover (or plain acetone) on hand to clean the stamper once you’ve finished, as well as your stencil. [Tamas] cautions you’ll want to clean it immediately if you ever want to use it again. Good to know.
While this is going outside of the nail art kit’s comfort zone, it might not quite be abuse. It is however a very useful technique to add to our ever-growing quiver of how to make front panels. Besides, we don’t specify you have to literally make components suffer; we just want to see what wild and wonderful substitutions and improvisations you all come up with.
2025-10-24 01:00:25
It’s the moment you hard-core hardware nerds have been waiting for: the reveal of the 2025 Hackaday Supercon Communicator Badge. And this year, we’ve outdone ourselves, but that’s thanks to help from stellar collaboration with folks from the community, and help from sponsors. This badge is bigger than the sum of its parts, and we’ve planned for it to be useful for you to hack on in the afterlife. Indeed, as always, you are going to be the final collaborator, so we can’t wait to see what you’ll do with it.
We’re going out – wide out – on a limb and trying to create a dense mesh network of badges talking to each other at Supercon. It’s going to be like a badge-hosted collection of chat rooms, as connected as we can make them without talking over each other.
You look up a topic, say Retro Computing or SAO trading, punch in the channel number on the numpad, and your badge starts listening to everything going on around that topic. But they also listen to everything else, and repeat anything they hear on to their neighbors. Like IRC, but LoRa.
But let’s talk hardware. The first thing that hits you is the custom keyboard, a hat-tip to portable computing devices of yore, but actually infinitely more capable and even nicer under the thumbs. Behind the keyboard is a custom dome-switch sticker sheet and a TC8418 I2C keyboard matrix multiplexer chip, which does away with all of the diodes and decoding and makes a keyboard design easy.
In the driver’s seat is an ESP32-S3, courtesy of Espressif, no less. We asked, and they made it rain: it’s the good one with 8 MB of PSRAM and 16 MB of flash – plenty of room for about anything, and just enough pins to run the show. We needed the form-factor of the LCD screen for the aesthetics, and we’ll just say there’s not much choice in this shape; we had to go for an LCD with a strange newish driver chip, but we made it work with the help of sketchy Arduino init scripts found around the interwebs.
Did we mention LoRa? A Communicator Badge is no good without a means of communication. Seeed makes these nice little SX1262 LoRa modules, and they were our first choice not only because they’re cute, but also because they come with a bring-your-own antenna option, and they had enough of them in stock. (This is not to be underestimated these days!) SMA adapter, LiPo and charging circuitry, and badge is your uncle! Super thanks go out to DigiKey for sponsoring us all manner of needed components.
Here is where we run into our first problem, and it’s the exact opposite of the problem that mesh networks are designed to solve. Those little LoRa radios transmit easily 1 km to 2 km in open space, maybe half that in an urban neighborhood. And we’re putting 500 hundred of them in the alley, with often just a couple meters between badges.
Still, we’ve got some tricks up our sleeve, we’ve got a lot of bandwidth at our discretion, and we’ve got a smart bunch of hackers. We can make this work, and we will have some odd corners of radio spectrum for you to play around with too. Get together with a couple friends and have fun with RF.
We’ll also be broadcasting Supercon-relevant news out to the badges from time to time. Things like which talks are coming up, when and where the food has arrived, and so on.
Back to the keyboard. Hackaday superfriend [Arturo182] was one of the first few people to make the new-old-stock Blackberry keyboards usable for the masses, building on the work of [JoeN] and [WooDWorkeR]. But hacker demand has dried up the global stock of the old gems, and [Arturo] turned to making his own keyboards. We saw his prototypes and had to get in on the action.
Other badges have come out using his stock keyboard, but only Hackaday and Supplyframe’s Design Lab was foolish enough to do something totally custom. Actually, it was super easy with [Arturo] leading the keyboard project, because he knows all about the details of preparing the designs for the keyboard dome sheets, and worked with the Design Lab team and Supplyframe’s designer [Bogdan Rosu] to get the custom silicone covers looking pretty. Thanks [Arturo]!
The software is still under wraps. The folks at Design Lab are turning out badges as fast as they can, even as we write this, and that means that we’re still working on the software. The last minute is the sweetest minute. Again, though, we’re not alone.
The brains behind the software effort is [Spaceben], and I have to say I haven’t seen such clean Python code in my life. Everything is possible when you have good folks on your team.
We’re using the LVGL graphics framework for Micropython, which makes the GUI design a lot snazzier than it would otherwise be. It was also easy enough to port our funny display driver to lvgl_micropython, and we’re working on the keyboard too. We’ll see what works on Supercon Day 1!
And that brings us to you! Mesh-network-IRC is fun during the conference, but after the fact, these badges are going to be too good to just leave on the shelf. Porting Meshtastic to the badge would be a fantastic project. The keyboard, WiFi, and Bluetooth connectivity just beg for some kind of handheld remote-control device design. The panel for a home automation setup? Or heck, go super simple and just wire the I2C keyboard out to your next project that needs one. We’d bet a Jolly Wrencher sticker that the badge could be quickly transformed into an ELRS radio control unit.
We love the badge scene, and like many of you out there, we find it’s a pity when the badges just sit in the closet. So we tried to plan for the afterlife here by making the badge hardware as useful as we could, and by making the software side as accessible as possible. Those of you who hack on the badge during Supercon, you’ll be blazing the trails for the rest of us afterwards.
We hope you find it fun to chat with others at Supercon, a fun platform to work on, and something useful after the fact. Managing an ad-hoc chaos mesh network isn’t going to be easy, but the real goal is the friends you meet along the way. See you all at Supercon!
2025-10-23 23:30:27
Compared to the old 8-bit Arduinos, it’s incredible how cheap modern microcontrollers like the ESP32 have become. But there are even cheaper options out there if you don’t need that kind of horsepower, and are willing to do a little work yourself, as [atomic14] demonstrates.
The CH32V003 is a dirt cheap microcontroller—which can reportedly be had for as little as 10 cents if you know where to look. It’s not the most powerful chip by any means, boasting just 16 K flash, and 2 K of SRAM. However, it is a 32-bit RISC V machine, and it does run at 48 MHz—giving it a leg up on many 8-bit parts that are still out there.
Surprisingly there aren’t a whole lot of CH32V003 products for the maker market, so if you want to play with it, you’ll probably need to spin up your own boards. [atomic14] does just that, showing us how the chip can be put to good use by turning it into a little musical trinket. It’s a fun demo, and a great way to get to grips with programming on a new microcontroller platform.
It’s hard to get more chiptune than a 10 cent chip beeping its little head off. How could possibly justify spending tens of dollars modding a Game Boy when this exists, even if it sounds like a caffeinated greeting card?
2025-10-23 22:00:45
Having a gadget’s battery nestled snugly within the bowels of a device has certain advantages. It finally solves the ‘no batteries included’ problem, and there is no more juggling of AA or AAA cells, nor their respective chargers. Instead each device is paired to that one battery that is happily charged using a standardized USB connector, and suddenly everything is well in the world.
Everything, except for the devices that cannot be used while charging, wireless devices that are suddenly dragging along a wire while charging and which may have charging ports in irrational locations, as well as devices that would work quite well if it wasn’t for that snugly embedded battery that’s now dead, dying, or on fire.
Marrying devices with batteries in this manner effectively means tallying up all the disadvantages of the battery chemistries and their chargers, adding them to the device’s feature list, and limiting their effective lifespan in the process. It also prevents the rapid swapping with fresh batteries, which is why everyone is now lugging chunky powerbanks around instead of spare batteries, and hogging outlets with USB chargers. And the task of finding a replacement for non-standardized pouch cell batteries can prove to be hard or impossible.
Looking at the ‘convenience’ argument from this way makes one wonder whether it is all just marketing that we’re being sold. Especially in light of the looming 2027 EU regulation on internal batteries that is likely to wipe out the existence of built-in batteries with an orbital legal strike. Are we about to say ‘good riddance’ to a terrible idea?
To further rub in how much of a terrible idea built-in batteries are, one only has to look at professional equipment, particularly in the audiovisual world. Whether we are talking about DSLRs, mirror-less cameras, or professional video cameras, they all have as standard feature the ability to quickly swap batteries. Nikon and Canon cameras use a range of proprietary-but-standard Li-ion batteries, with Sony’s video camera batteries also used on portable studio lighting. For the super-expensive Red video cameras you can use either the massive Redvolt batteries that dangle off the side or a power adapter.
The reasoning here is simple: when you are doing a photo or film shoot you do not have time for charging, so you load up with a stash of charged batteries beforehand. As the current battery becomes drained, you pop open the battery hatch or detach the current pack and slam in a fresh battery before resuming. During moments of downtime you can put the drained batteries on the charger that you have squirreled away somewhere. This way you stay wireless and charged with zero fuss, and if you have enough batteries, zero downtime.
Even within the era of budget photo and video cameras you’d be able to do this. When it comes to my own JVC camcorder and Canon IXUS 100 IS point-and-shoot camera, both offer this feature, even if the battery swapping experience doesn’t feel as premium as with the Nikon D7200 DSLR and its EN-EL15 batteries that is used for more serious occasions. Swapping batteries with the DSLR in particular is as easy as swapping SD cards, which is to say a matter of seconds.
One might get the idea here that the main reason to stuff a pouch cell somewhere inside the device is mostly a cost-saving measure, as it omits the battery terminals and ejection mechanism for the pack.
Another reason why having a built-in battery with a multi-thousand-Euro DSLR would be a terrible idea beyond the insanity of having to ‘charge the DSLR’, is that the battery will be dead long before even the warranty on the DSLR has expired, especially if you are an avid shooter. Even if you do not use a device that much, the fact of the matter is that lithium-ion cells begin to degrade as soon as they have been manufactured. This may be acceptable in a €1,000+ smartphone when people buy a new one every other year anyway, but becomes a problem when you’d like to use a device for much longer.
A good summary of the how and why of lithium-ion batteries (LIB) can be found in this IEEE review article by Wiljan Vermeer et al. from 2021. The three main aging mechanisms are:
There are multiple ways in which each type of aging can occur, with most requiring the cell to be charged and discharged, as this inflicts mechanical and other types of stress. When it comes to storing LIBs, we enter the territory of calendar aging. This has an irreversible and reversible component, the former being impacted by three components: the state of charge (SoC), temperature, and time.
What this tells us is that although you can affect LIB calendar aging, it’s a pretty inevitable aspect of their chemistry. This is true even in the case of the lithium-polymer (LiPo) LIB type batteries with its polymer electrolyte. This effectively means that charging the battery in a device to 80% instead of 100% will give it some more life, but you’d have to drop down to 50% or less to see the big gains. It’s also highly advisable to keep the battery relatively cool, which is where fast-charging is a terrible idea, especially as the resistance of the battery goes up due to aging.
While the exact mechanisms behind calendar aging are still being investigated, it’s likely that the layer that forms at the electrochemically unstable electrolyte-electrode interface (SEI) restructures to prevent the transfer of lithium ions, effectively increasing the measured resistance via the CL aging path.
In addition to calendar aging you have the charge-discharge cycle-based aging mechanisms, which not only affects the SEI, but also causes mechanical expansion of the graphite anode material, which leads to both the LLI and LAM aging paths. When you then add in the typical charging method for gadgets like smartphones using a LIB-based powerbank, you end up with double the charge-discharge cycles over simply slotting in a fresh battery.
Beyond larger electronic devices, pouch cell LIBs are now integrated in countless more gadgets, from lamps to Bluetooth speakers. To address the sheer volume of these built-in LIBs, the EU’s Battery Regulation will begin to enforce its removability and replaceability requirements starting on 18 February of 2027.
The batteries which we discussed in this article fall under so-called ‘portable batteries’, meaning that it weighs less than 5 kg and is not used for an electric vehicle. These are required to make it possible for the end user to replace and remove, all without damaging or destroying the battery or the device, and without requiring any special tools. There are some partial safety-related exceptions where a professional can do said replacement, while a full exception is limited to a number of very specific device categories.
What exactly the fallout of this change will be remains to be seen, with manufacturers likely starting to adapt their products throughout 2026. Devices like smartphones, game controllers, but also Bluetooth speakers, wireless mice and portable game consoles will all be affected, so it’ll be interesting to see what approach we will see here.
Perhaps most of all what it might mean for standardization of cells and batteries, as every device that’s put on the market in the EU must have spare batteries available for reasonable cost for five years after it stops being sold. Clearly this would be cheaper if the same battery just got used for decades, somewhat like the veritable AA cell and today’s 18650 and similar formats.
The process of standardization is a rough one, with sometimes the legislature leaning into the issue after consultation with a requirement, as with USB-based chargers. Other times the market simply picks something that’s readily available and does the job. One example of this is the Nokia BL-5C battery and its variations, which was quite prevalent due to Nokia using it for its phones and other platforms like the N-Gage. Consequently third-party manufacturers made their own compatible versions for use in a wide range of devices.
While the BL-5C is still fairly large, at 53 mm x 34 mm and a thickness of 6 mm, point and shoot cameras as well as action cameras feature a range of smaller batteries, with the Canon NB-4L as used in the IXUS point and shoot cameras providing more than 750 mAh in a 35 mm x 40 mm package and a similar 5.9 mm thickness. The third-party replacements that I got of the NB-4L claim to provide 1,200 mAh, as modern LIBs tend to have more capacity within the same form factor due to more refined manufacturing.
Interestingly, even rechargeable AA-sized cells aren’t limited to NiMH chemistry any more, with Li-ion options now available yet still providing the 1.5 V one would expect. This does require a bit of electronics in the cell, and results in them having a capacity that’s similar to that of NiMH AA cells, while suffering all the aging issues of any other LIB in addition to the limited number of charge cycles. Assuming that the 1.2 V of NiMH cells is acceptable, then devices could accept AA or AAA NiMH cells.
Of note here is that none of this means that having a power input port for charging the battery or cell inside the device itself is no longer possible or allowed. Depending on the device manufacturer, the new EU regulations should mean little difference for the end user, other than having the option to pop open each device to extract and replace the battery. This could mean that wireless mice and Bluetooth headsets will soon feature an alternative to sticking in that charge cable and have the device be mostly useless until its built-in battery has soaked up sufficient juice.
Although this is an EU-only thing, it’s likely to come to every other part of the globe as well.
