TechyMagThings

Surveillance cameras from Flock Safety have become a controversial privacy battleground, as the communities in which they are installed wake up to their sinister potential, and stories roll in of law enforcement professionals abusing their access. One has had its disk contents dumped, and we’ve been treated to some insights courtesy of [Micah Lee]. In short: their approach to security is deeply flawed.

It’s interesting to find that instead of a custom hardened OS, these devices run Android. Not just Android, but Android 8.1, a long out of support version originally released in 2017. This is is the year Flock Safety was founded, which may or may not be coincidental. Like any old version of a widely used operating system it has a host of known vulnerabilities, none of which are patched on this version.

The Android version is small beer compared to the revelation that they contain a hard-coded and very open-access API key that can be used by any mildly curious miscreant to reveal information from any Flock camera using its MAC address. One would hope that a product marketed for use by law enforcement might have paid attention to such a basic lapse, but it seems not. Whether or not this can be corrected by a software upgrade and the leaked key deactivated without turning off the network depends on whether thy can do upgrades tailored to specific devices, but either way we wouldn’t like to be the team tasked with fixing that one.

In a way it’s reassuring that the surveillance apparatus when it came was so incompetently managed, and we hope that these vulnerabilities will have moderated its effect. We’re sure more tasty discoveries will emerge as investigations proceed, and we’ve got the popcorn ready.

Image: Tony Webster, CC BY 2.0.

The Cheap Yellow Display is an all-in-one ESP32 board with a touchscreen, that’s as the name suggests, cheap. It’s appeared in a great many projects since it emerged from the depths of AliExpress, and today thanks to [Nickm324] it takes the turn of becoming a mini TV.

The tiny TV project world is one of successive developers building on previous works to deliver their own refinements on the idea, so this one borrows heavily from an earlier ESP32 project. Its twist on the idea is a single button interface using the CYD’s BOOT button. It supports a range of “channels” of which each one is a different piece of media played from the SD card. As far as we can see it’s only able to play synchronised .mjpeg and audio files, probably a shortcoming of the older ESP32 found on the CYD. The photo features a rather cutesy retro 3D printed TV case which annoyingly isn’t linked from the repository at the time of writing.

It’s a nice idea, and the CYD makes it as easy as possible with minimal wiring. Yes it’s a novelty, but we’re guessing there could be many non-novelty applications for it too. It’s certainly not the first such project we’ve seen, here’s an earlier one.

With an El Niño event in full swing those of us in the northern hemisphere have just had a roasting hot summer, and those in the southern are about to have one. We know what that means, even with the best laid plans the slightest bit of exercise is going to raise a lot of sweat. And if you’re carrying a backpack that means a soaking down your back. Never fear though, because for that one, [Crafterboi] is here with a fan-assisted back protector.

The idea is simple enough, an open framework that sits between you and the backpack, allowing air to flow. If that weren’t enough, there are a couple of 5 volt fans at the top to blow air through the space. It’s printed using PETG, because as he explains, on a really hot day some surfaces can exceed the temperature at which PLA starts to soften.

We like the idea of this project, but what we especially like is that his prototype was made of a pizza box. ten out of ten for resourcefulness! Meanwhile this isn’t the first time we’ve seen a cooling backpack as others have had Peltier systems and evaporative coolers. We would link you to them, but sadly those are both from Hackaday’s early years and link rot has taken their websites.

With the Earth’s atmosphere being effectively just a less dense fluid than the oceans around us, it’s reasonable to ask why we got wind turbines and wind mills quite literally everywhere across the globe to harvest the power in the wind, whereas ocean waves and currents aren’t being exploited quite as much. In a recent video by [Giordano Scarciotti] this issue with wave power is addressed, in particular the massive engineering challenges involved.

One of the main problems is simply one of cost, with wind energy having converged on a single design involving effectively the same three-bladed rotor, gondola and tower design that has been optimized for decades now. For wave energy there’s no such one-design-fits-all solution, with each attempted design having its own advantages and disadvantages that may prevent it from working in various sites, or incur high maintenance costs in the highly abusive marine environment.

Having more energy in waves than in wind is also both a benefit and a curse, as wave turbines have to work with the waves and not get demolished every time there’s a storm. Even wind turbines regularly fail in windy weather when e.g. the brakes fail, under conditions that would be considered mild in a marine context.

Also covered in the video is a new contender, in the form of CorPower Ocean’s new buoy-like design that bobs up and down on the surface. Here you need to carefully tune the turbine mechanism to work with the wave motion to extract the most energy. Their current design is be 19 meters tall, 9 meters wide and claimed to be capable of being installed in >40 meter deep water, producing power with a 40-60% capacity factor at 300 kW.

As yet another attempt at making wave energy turbines work, the most exciting aspect of it will be to see whether it can survive adverse weather, when careful tuning gets tossed out of the window and chaotic waves pummel what is essentially a very big hollow buoy. The single prototype has so far survived bad weather off the coast of Portugal during a year of testing, but the real test is long-term survival, as losing half your wave turbine farm to a really bad storm every five-odd years would quickly scuttle the project like it has previous commercial contesters.

Although not addressed in the video, the commercial challenge here is also not so much making the power generated over its lifetime (LCoE) economically attractive, but also its system integration cost in terms of required transmission lines, grid-level energy storage and backup power generators like baseload and standby power plants. Without equipping these wave power farms with grid-forming converters as TSOs are asking, dealing with reactive power to absorb and generate it, any resulting grid oscillations exacerbated by grid-following converters risk causing another expensive blackout as recently on the Iberian peninsula.

Although things may seem simple on the North American grid as an end-user if you limit yourself to just 120 VAC and NEMA 1-15 and 5-15 connectors, there is a veritable zoo of different voltages and receptacles out there in the NEMA connector catalogue. Recently [Practical Engineering] decided to not only take a look at how many of these defined standards are actually used, but also put them in a nice periodic table style graphic.

Responsible for these standards is the National Electrical Manufacturers Association (NEMA), which as the name says is a collection of manufacturers. Founded in 1926, this US trade association also affects outlet standards in countries like Canada, Mexico, Japan and so on. The caveat here is that compatibility between e.g. a similar looking Japanese 1-15-style plug and a US 1-15 outlet is not guaranteed, even if you ignore voltage and grid frequency differences.

In an ideal world everyone would agree on a set of reasonable connector designs and we could move on, but we live in a world where even today designing your own national connector instead of picking something like the ubiquitous Type F is considered to be reasonable. At least it’s not susceptible to the ‘penny challenge‘ flaw that the NEMA 5-15 connector suffers from, but that’s small comfort.

NEMA connectors are also unique in that they are often polarized, while Type E/F and others rarely are, putting the onus of dealing with AC polarity on the device. This already shows why the NEMA connector diversity exists, as this trade association wanted to have specific connectors for different polarities, different current limits and also the nearly half a dozen of different voltages commonly used throughout the US.

This ‘one connector for a specific combination’ approach means that quite a few of them are not really used in real life, though from a European perspective where you deal with Type C (‘euro plug’) and Type E/F (‘Schuko’)  on ~240 VAC and triple-phase 440 VAC connectors if you run a heavy machine shop or want to fast-charge an EV at home, it’s still a bewildering number of active combinations.

The US has tons of abandoned rail, especially in urban environments, so it seems a shame to let it go to waste. [OneWheel] decided to modify one of their boards to ride the rail behind their office.

The stock OneWheel frame was sectioned and CNC cut mounts were placed in the center to raise the motor above the deck. Steel rail wheels sourced from eBay were then attached to an axle run through where the original wheel was mounted in the center. The motor housing was turned down on a lathe for better clearance, and then a bike sprocket was attached to chain drive the train axle.

While not everyone has a hydraulic press and a CNC for that professional look, we don’t see any reason you couldn’t bodge something similar together at home. Be sure to watch [Bradley Gawthrop]’s Supercon talk on the Personal Electric Vehicle Revolution for some ideas on what you need to get started.

Dream of riding the rails yourself? You should checkout this tiny rail riding pod car or this more minimalist example. Definitely make sure you’re riding on a truly abandoned line or get a rail warrant though!

Once upon a time, doing graphics on a microcontroller was challenging, to say nothing of the concept of going into three dimensions. But modern microcontrollers are far more powerful, and you might find yourself wanting to do all sorts of graphical wizardry with one. To that end, you might find Jet useful.

Created by [CubeCoders], Jet is a compact 3D rasterizer built for modern chips like the ESP32 and STM32. It’s dependency free, relatively tiny, and is written in C++17 with an eye towards working well on memory-limited platforms. It runs entirely in software, uses only integer arithmetic, and is built around 16-bit RGB565 color — intended to make it easy to use with parts like the ST7796, ILI9488, and other similar displays interfaced via SPI.

As a point of reference, on a ESP32-S3 Jet can render around 650 on-screen triangles (post-culling) at 60 frames per second on a 480×320 display, or 1300 triangles at 30 FPS. The developers note that 3D performance lands somewhere between the Sega 32X and Sega Saturn — not bad for a microcontroller you can buy for under $20. The Wipeout-like demo shows off the capabilities of Jet rather fantastically, we think.

You’d be foolish to expect your next microcontroller project to render Crysis. However, if you want some retro 3D graphics for your next ESP32-based build, you might just consider exploring what Jet can do for you.