2026-04-11 19:00:15
Waveshare makes a nifty little ESP32-S3 based smartwatch product, but its firmware is apparently not to everyone’s liking. Specifically, it’s not to [infiniton] a.k.a [Bright_Warning_8406]’s liking, as they rewrote the entire code base in Rust. No_std Rust, to be specific, but perhaps that doesn’t need to be specified when dealing with ESP32.
On the Reddit thread about the project, he lists some of the advantages. For one thing, the size of the binary has dropped from 1.2 MB to 579 kB while maintaining the same functionality. More interesting is that he’s been able to eliminate polling entirely: the firmware is purely event-driven. The CPU is not just idle but parked until a timer or GPIO event wakes it up. For this form factor, that’s a big deal — you can’t fit a very large battery in a watch, after all.
Getting drivers for the AMOLED display, touch sensor, audio, and RTC modules written from scratch is an impressive accomplishment. Apparently the screen driver in particular was “a nightmare” and we believe it. There’s a reason most people go for existing libraries for this stuff. [Bright_Warning] did not post screenshots or video, but claims his version of the watch watch can make HTTP calls to Smart Home, play MP3s, play the old phone games– Snake, 2048, Tetris, Flappy Bird, Maze– and even comes with a T9 keyboard for text input.
If you’re looking to get closer to bare metal, and don’t mind it being Rust-y, take a look at the code on GitHub in the first link above. This author isn’t enough of a rustacean to say if the code is as good as it sounds at a glance, but nothing egregious jumps out. The documentation describing exactly what’s going on under the hood isn’t half-bad, either. If you aren’t into Waveshare products, you could easily adapt this code into a more DIY ESP32 watch, too.
If you’re not into Rust, uh… washing soda and electric current can get it off of steel, and probably microcontrollers too. We can’t say that the chip will work after that, but hey — no rust.
2026-04-11 16:00:47
With each new game console, there’s an effort to get around whatever restrictions exist to run your own software on it. In the case of the Nintendo Wii, the system was cracked through one of its most popular games — The Legend of Zelda: Twilight Princess. How this hack works was recently covered in detail by [Skawo].
The key for this ‘Twilight Hack‘ is to use a modified game save that allows you to run arbitrary code from an SD card, something which was first patched out of the Wii firmware with version 3.3. As shown in the video using the source code, the basic concept is that the name of Link’s horse in the game is changed in the save file to be longer than the allocated buffer, which leads to a buffer overflow that can be used to reach the application loader code.
Interestingly, while the horse’s name can only be 8 characters long, and the buffer is 16 bytes (due to ShiftJS two-byte encoding), the save file loading code allocates no less than 100 bytes, for some reason. Since the code uses strcpy() instead of strncpy() (or C11’s strncpy_s()), it will happily keep copying until it finds that magic 0x00 string terminator. Basically the horse can have any name that fits within the save file’s buffer, just with no null-byte until our specially crafted payload has been copied over.
Although it took Nintendo a few months to respond to this hack, eventually it was patched out in a rather brutal fashion by simply searching for and wiping any modified save files. Naturally this didn’t stop hackers from finding ways to circumvent this save file check, which led to more counter-fixes by Nintendo, which led to more exploits, ad nauseam.
Even with firmware update 4.0 finally sunsetting the Twilight Hack, hackers would keep finding more ways to get their previous Homebrew Channel installed, not to mention so that they could keep watching DVDs on a Wii.
2026-04-11 13:00:28
Analog synths are fun because they combine music, which all humans seem hard-wired to enjoy in one form or another, and electronics, which… uh, this is Hackaday. If you don’t like electronics, we’re not sure what to tell you. This hack from [Sound Workshop] takes the cheap, toy-like Otamatone and turns it into an older and more capable type of synthesizer: a Trautonium. The video below also includes a dive into the different types of early synthesizers, with examples of them playing, so it’s worth watching for that alone — if you know the history, skip the first five minutes or so.
For those of you more into the electronics than the music side of things, the Otamatone is kind of like an electronic slide whistle, but adorable. Shaped like an eighth note or a tadpole, you control pitch by sliding your fingers up and down the ‘tail’ and activate the voice by squeezing the ‘head’ to open the mouth. It is one of the newest electronic instruments on the market, having debuted as a Japanese toy in 2009.
The Trautonium is more than five times older, having been invented in 1930, and is a more capable instrument. It keeps the pitch slider, but adds some nice tactile bumps so you can actually hit specific notes– but more importantly, it adds tactile volume control. The pitch slider on the Trautonium is horizontal rather than vertical, and it doubles as a volume control: the harder you push, the louder it gets. That means everything musical is done with one hand, leaving the other hand free to twist knobs or work patch cables to max out the analog electronic fun.
The build itself starts at about 6:55 into the video. In simplest terms — audio out from the Otamatone goes through a low-pass filter, whose volume slider has been replaced by a pair of hall-effect sensors tracking the vertical motion of a flexing plate of metal. The original touch sensor has been glued to that plate, giving the one-finger pitch-and-volume control of a Trautonium. The circuitry gluing it all together is made of a handful of op-amps and passives– there’s no Arduino here, this is analog country.
If this isn’t enough Trautonium for you, we did a deep dive on the instrument long, long ago. We’ve also seen analog synths shaped like everything from keyboards to hurdy-gurdies.
2026-04-11 10:00:05
With multiple rovers currently scurrying around on the surface of Mars to continue a decades-long legacy, it can be easy to forget sometimes that repeating this feat on other planets that aren’t Earth or Mars isn’t quite as straightforward. In the case of Earth’s twin – Venus – the surface conditions are too extreme to consider such a mission. Yet Mercury might be a plausible target for a rover, according to a study by [M. Murillo] and [P. G. Lucey], via Universe Today’s coverage.
The advantages of putting a rover’s wheels on a planet’s surface are obvious, as it allows for direct sampling of geological and other features unlike an orbiting or passing space probe. To make this work on Mercury as in some ways a slightly larger version of Earth’s moon that’s been placed right next door to the Sun is challenging to say the least.
With no atmosphere it’s exposed to some of the worst that the Sun can throw at it, but it does have a magnetic field at 1.1% of Earth’s strength to take some of the edge off ionizing radiation. This just leaves a rover to deal with still very high ionizing radiation levels and extreme temperature swings that at the equator range between −173 °C and 427 °C, with an 88 Earth day day/night cycle. This compares to the constant mean temperature on Venus of 464 °C.
To deal with these extreme conditions, the researchers propose that a rover might be able to thrive if it sticks to the terminator, being the transition between day and night. To survive, the rover would need to be able to gather enough solar power – if solar-powered – due to the Sun being very low in the sky. It would also need to keep up with the terminator velocity being at least 4.25 km/h, as being caught on either the day or night side of Mercury would mean a certain demise. This would leave little time for casual exploration as on Mars, and require a high level of autonomy akin to what is being pioneered today with the Martian rovers.
Top image: the planet Mercury with its magnetic field. (Credit: A loose necktie, Wikimedia)
2026-04-11 07:00:14
Most rhythm games have a community creating custom charts, and Trombone Champ is no exception. What is exceptional, however, [CraftedCart]’s osu! played in a Trombone Champ chart.
It all started as a challenge to make the most unserious chart possible. Among some other ideas, [CraftedCart] eventually decides to make an osu! chart but play it in Trombone Champ. Okay, not a problem, let’s just–oh, you can’t run arbitrary code without a making a mod. So instead, they decided to use shaders on the GPU. There are, of course, all sorts of problems with such an idea. Being stuck in the fixed render pipeline of a game, you can’t just add any resources to your shader you want. This leads to using textures as memory, both the game state and the osu! chart are actually textures. Another interesting one is getting user input into the shader. [CraftedCart] solves that by connecting the position of the game object the background is rendered to to the cursor; then, the shader reads the world to local transform matrix to determine the mouse position. Finally, the graphics the player ends up seeing are rendered using ray marching.
Video after the break.
2026-04-11 04:00:52
After users of Battle Born LFP batteries encountered issues such as a heavily discolored positive terminal and other signs of overheating, multiple autopsies showed that the cause appeared to be the insertion of a thermoplastic between the bus bar and the terminal. Over time thermal creep loosened the connections, causing poor contact and melting plastic enclosures. According to Battle Born, this is actually part of an ingenious thermal safety design, and in a recently published article they explain how it works.
The basic theory appears to be that if there’s a thermal event, the ABS thermoplastic will soften and reduce the pressure on the bolted-together copper bus bar and brass terminal. This then allows for an aluminium-oxide layer to form on the aluminium connecting bolt courtesy of the dissimilar copper/aluminium interface. Aluminium-oxide is non-conductive and thus interrupts the flow of current.
Of course, there are countless issues with that theory, least of all the many reports of in-field failures. We recently covered [Will Prowse] studying the death of one of these 100 Ah LFP batteries from brand-new to failure under controlled circumstances. This clearly shows the thermal creep loosening up the connection and causing poor contact between the bus bar, the bolt and the terminal, with poor contact and thermal issues resulting.
Naturally, [Will Prowse] had to address this most recent statement by Battle Born, with the latter taking care to indirectly attack and dismiss his findings. Here Battle Born’s argument seems to hinge on the removal of the lid damaging this aluminium-oxide layer and preventing the ‘thermal safety’ from working, yet not addressed are the many batteries that failed in the field and showed loose connections due to thermal creep from the ABS layer.
It’s also never addressed why these LFP batteries cannot simply be equipped with a traditional thermal fuse rather than this convoluted contraption, among many other questions that remain. Correspondingly [Will] is rather incredulous at this response, as should anyone be who has been following this saga.
