No-Battery Pressure Sensors For Bike Tyres

Finding out you’ve got a flat tyres halfway into a long ride is a frustrating experience for a cyclist. Maintaining the

While the epoxy does a great job of sealing the PCB to the valve extension, the overmoulding process would likely be key to producing a product with shelf-quality fit and finish. This test run was done with 3D printed ABS moulds.

correct tyre pressures is key to a good ride, whether you’re stacking up the miles on the road or tackling tricky single track in the mountains. [CaptMcAllister] has put together a device that makes keeping an eye on your tyres easy.

The device consists of an ultra low power microcontroller from Texas Instruments, paired with a pressure sensor. Set up for Near Field Communication, or NFC, it’s designed to be powered by the smartphone that queries the microcontroller for a reading. We featured a prototype back in 2015 which required mounting the device within the inner tube of the tyre itself. However, this required invasive installation and the devices tended to wear out over time due to flex damaging the delicate copper coil antenna.

The new design consists of the same microcontroller hardware, but mounted in a modified valve extension that fits to the fill valve of the bicycle tyre. The PCB is directly epoxied on to the valve extension, ensuring air can’t leak out over time. The assembly is then overmoulded in an injection moulding process to provide further sealing and protection against the elements. This should help immensely in rough-and-tumble mountain biking applications.

The new device provides a simple screw-on solution for tire pressure monitoring that’s set and forget — no batteries required. [CaptMcAllister] is currently investigating options for a production run, and given the simple design, we imagine it couldn’t be too hard to rattle off a few hundred or thousand units. We could imagine it would also pair well with a microcontroller, NFC reader, and a display setup on the handlebars to give live readings where required. We look forward in earnest to seeing where this project goes next!

Road Pollution Doesn’t Just Come From Exhaust

Alumni from Innovation Design Engineering at Imperial College London and the Royal College of Art want to raise awareness of a road pollution source we rarely consider: tire wear. If you think about it, it is obvious. Our tires wear out, and that has to go somewhere, but what surprises us is how fast it happens. Single-use plastic is the most significant source of oceanic pollution, but tire microplastics are next on the naughty list. The team calls themselves The Tyre Collective, and they’re working on a device to collect tire particles at the source.

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Hackaday Links: August 23, 2020

Apple, the world’s first trillion-dollar company — give or take a trillion — has built a bit of libertarian cachet by famously refusing to build backdoors into their phones, despite the entreaties of the federal government. So it came as a bit of a surprise when we read that the company may have worked with federal agents to build an “enhanced” iPod. David Shayer says that he was one of three people in Apple who knew about the 2005 program, which was at the behest of the US Department of Energy. Shayer says that engineers from defense contractor Bechtel, seemed to want to add sensors to the first-generation iPod; he was never clued in fully but suspects they were adding radiation sensors. It would make sense, given the climate in the early 2000s, walking down the street with a traditional Geiger counter would have been a bit obvious. And mind you, we’re not knocking Apple for allegedly working with the government on this — building a few modified iPods is a whole lot different than turning masses of phones into data gathering terminals. Umm, wait…

A couple of weeks back, we included a story about a gearhead who mounted a GoPro camera inside of a car tire. The result was some interesting footage as he drove around; it’s not a common sight to watch a tire deform and move around from the inside like that. As an encore, the gearhead in question, Warped Perception, did the same trick bit with a more destructive bent: he captured a full burnout from the inside. The footage is pretty sick, with the telltale bubbles appearing on the inside before the inevitable blowout and seeing daylight through the shredded remains of the tire. But for our money, the best part is the slo-mo footage from the outside, with the billowing smoke and shredded steel belts a-flinging. We appreciate the effort, but we’re sure glad this guy isn’t our neighbor.

Speaking of graphic footage, things are not going well for some remote radio sites in California. Some towers that host the repeaters used by public service agencies and ham radio operators alike have managed to record their last few minutes of life as wildfires sweep across the mountains they’re perched upon. The scenes are horrific, like something from Dante’s Inferno, and the burnover shown in the video below is terrifying; watch it and you’ll see a full-grown tree consumed in less than 30 seconds. As bad as the loss of equipment is, it pales in comparison to what the firefighters face as they battle these blazes, but keep in mind that losing these repeaters can place them in terrible jeopardy too.

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Hackaday Links: August 9, 2020

We regret to admit this, but we completely missed the fact that Windows 10 turned five years old back in March. Granted, things were a little weird back then — at least it seemed weird at the time; from the current perspective, things were downright normal then. Regardless, our belated congratulations to Microsoft, who, like anyone looking after a five-year-old, spends most of their time trying to keep their charge from accidentally killing itself. Microsoft has done such a good job at keeping Windows 10 alive that it has been installed on “one billion monthly active devices”. Of course, back in April of 2015 they predicted that the gigainstall mark would be reached in 2018. But what’s a couple of years between friends?

Of all the things that proved to be in short supply during the pandemic lockdowns, what surprised us most was not the toilet paper crunch. No, what really surprised us was the ongoing webcam supply pinch. Sure, it makes sense, with everyone suddenly working from home and in need of a decent camera for video conferencing. But we had no idea that the market was so dominated by one manufacturer — Logitech — that their cameras could suddenly become unobtainium. Whatever it is that’s driving the shortage, we’d take Logitech’s statement that “demand will be met in the next 4-6 weeks” with a huge grain of salt. After all, back-to-school shopping is likely to look vastly different this year than in previous years.

Speaking of education, check out the CrowPi2 STEM laptop. On the one hand, it looks like just another Raspberry Pi-based laptop, albeit one with a better level of fit and finish than most homebrew Pi-tops. With a Raspberry Pi 4b on board, it can do all the usual stuff — email, browse the web, watch videos. The secret sauce is under the removable wireless keyboard, though: a pretty comprehensive electronics learning lab. It reminds us of the Radio Shack “150-in-One” kits that so many of us cut our teeth on, but on steroids. Having a complete suite of modules and a breadboarding area built right into the laptop needed to program it is brilliant, and we look forward to seeing how the Kickstarter for this does.

Exciting news from Hackaday Superfriend Chris Gammell — he has launched a new podcast to go along with his Contextual Electronics training courses. Unsurprisingly dubbed the Contextual Electronics Podcast, he already has three episodes in the can. They’re available as both video and straight audio, and from the few minutes we’ve had to spend on them so far, Chris has done a great job in terms of production values and guests with Sophy Wong, Stephen Hawes, and Erik Larson leading off the series. We wish him luck with this new venture, and we’re looking forward to future episodes.

One of the best things about GoPro and similar sports cameras is their ability to go just about anywhere and show things we normally don’t get to see. We’re thinking of those gorgeous slo-mo selfies of surfers inside a curling wave, or those cool shots of a skier powder blasting down a mountain slope. But this is the first time we’ve seen a GoPro mounted inside a car’s tire. The video by the aptly named YouTuber [Warped Perception] shows how he removed the tire from the wheel and mounted the camera, a battery pack, and an LED light in the rim, then remounted the tire. The footage of the tire deforming as it contacts the ground is fascinating but oddly creepy. It sort of reminds us a little of the footage from cameras inside the Saturn V fuel tanks — valuable engineering information to be sure, but forbidden in some way.

Arduino + Geometry + Bicycle = Speedometer

It is pretty easy to go to a big box store and get a digital speedometer for your bike. Not only is that no fun, but the little digital display isn’t going to win you any hacker cred. [AlexGyver] has the answer. Using an Arduino and a servo he built a classic needle speedometer for his bike. It also has a digital display and uses a hall effect sensor to pick up the wheel speed. You can see a video of the project below.

[Alex] talks about the geometry involved, in case your high school math is well into your rear view mirror. The circumference of the wheel is the distance you’ll travel in one revolution. If you know the distance and you know the time, you know the speed and the rest is just conversions to get a numerical speed into an angle on the servo motor. The code is out on GitHub.

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Glue Your Sumo Robot To The Mat With Custom Sticky Tires

Mini Sumo seems like one of those hobbies that starts out innocently enough, and ends up with a special room in the house dedicated to it. One day you’re excitedly opening up your first Basic Stamp kit, and the next you’re milling out mini molds on a mini lathe to make mini extra sticky tires.

[Dave] started out trying to find a part from the local big box store that was just a little bigger than the wheel he wanted to rubberize. He set the wheel inside a plumbing cap and poured the urethane in. It worked, but it required a lot of time with a sharp knife to carve away the excess rubber.

In the meantime he acquired a Sherline Mini Mill and Lathe. With the new tools available to him, he made a new mold out of a bit of purple UHMW and some acrylic. This one produced much nicer results. Using a syringe he squeezed resin into the mold through a hole in the acrylic. Much less cleanup was needed.

He later applied these methods to smaller, wider wheels as his mini sumo addiction took a stronger hold on his life.

Retrotechtacular: Brunswick Shows A Bias For Tires

Somewhere between the early tires forged by wheelwrights and the modern steel-belted radial, everyone’s horseless carriage rode atop bias-ply tires. This week’s film is a dizzying tour of the Brunswick Tire Company’s factory circa 1934, where tires were built and tested by hand under what appear to be fairly dangerous conditions.

It opens on a scene that looks like something out of Brazil: the cords that form the ply stock are drawn from thousands of individual spools poking out from poles at jaunty angles. Some 1800 of these cords will converge and be coated with a rubber compound with high anti-friction properties. The resulting sheet is bias-cut into plies, each of which is placed on a drum to be whisked away to the tire room.

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