No-Battery Pressure Sensors For Bike Tyres

December 6, 2020 by Lewin Day 55 Comments

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!

The Most Annoying Among Us Tasks Created In Real Life

November 22, 2020 by Lewin Day 12 Comments

Among Us is a hit game of deception and intrigue. Those who have played it know the frustration of trying to complete some of the intentionally difficult tasks onboard the Skeld. [Zach Freedman] decided to recreate some of these in real life.

[Zach] built what are arguably the three most frustrating tasks from the game. There’s the excruciatingly slow upload/download station built out of an old Samsung tablet and an NFC tag, and the reactor start console created using a Raspberry Pi 3B, Teensy 3.2, and a custom mechanical keyboard. But perhaps most annoying of all is the infamous card reader. Built with another Teensy, it requires the user to swipe their ID card at just the right speed, except that speed is randomly generated for every swipe. Also, the machine fails 20% of good swipes just because. Perhaps what we love most is the way [Zach] recreated the classic VFD look by putting an OLED display behind bottle-green plastic and using a 14-segment font.

It’s a fun homage to a wildly successful indie game, and we could imagine these props would be a hit at a makerspace party. We’ve featured other Among Us themed builds before, too. Video after the break.

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Hackaday Podcast 082: DJ CNC, NFC Black Box, Sound Of Keys, And Payin’ For 3D Prints

August 28, 2020 by Mike Szczys 2 Comments

Hackaday editors Elliot Williams and Mike Szczys check in on the best hacks from the past week. All the buzz is the algorithm that can reverse engineer your house keys from the way they sound going into the lock. Cardboard construction goes extreme with an RC car build that’s beyond wizard-level. Speaking of junk builds, there’s a CNC mill tipped on its side grinding out results worlds better than you expect from something made with salvaged CD-ROM drives. And a starburst character display is a clever combination of laser cutting and alternative using UV-cured resin as a diffuser.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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Breaking Smartphone NFC Firmware: The Gory Details

August 23, 2020 by Sven Gregori 2 Comments

Near-field Communication (NFC) has been around a while and is used for example in access control, small data exchange, and of course in mobile payment systems. With such sensitive application areas, security is naturally a crucial element of the protocol, and therefore any lower-level access is usually heavily restricted and guarded.

This hardware is especially well-guarded in phones, and rooting your Android device won’t be of much help here. Well, that was of course only until [Christopher Wade] took a deep look into that subject, which he presented in his NFC firmware hacking talk at for this year’s DEF CON.

But before you cry out “duplicate!” in the comments now, [Jonathan Bennett] has indeed mentioned the talk in a recent This Week In Security article, but [Christopher] has since written up the content of his talk in a blog post that we thought deserves some additional attention.

To recap: [Christopher] took a rooted Samsung S6 and searched for vulnerabilities in the NFC chip’s safe firmware update process, in hopes to run a custom firmware image on it. Obviously, this wouldn’t be worth mentioning twice if he hadn’t succeeded, and he goes at serious length into describing how he got there. Picking a brain like his by reading up on the process he went through — from reverse engineering the firmware to actually exploiting a weakness that let him run his own code — is always fascinating and downright fun. And if you’re someone who prefers the code to do the talking, the exploits are on GitHub.

Naturally, [Christopher] disclosed his findings to Samsung, but the exploited vulnerability — and therefore the ability to reproduce this — has of course been out there for a long time already. Sure, you can use a Proxmark device to attack NFC, or the hardware we saw a few DEF CONs back, but a regular-looking phone will certainly raise a lot less suspicion at the checkout counter, and might open whole new possibilities for penetration testers. But then again, sometimes a regular app will be enough, as we’ve seen in this NFC vending machine hack.

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Son Of Rothult

July 26, 2020 by Brian McEvoy 6 Comments

We are continuously inspired by our readers which is why we share what we love, and that inspiration flows both ways. [jetpilot305] connected a Rothult unit to the Arduino IDE in response to Ripping up a Rothult. Consider us flattered. There are several factors at play here. One, the Arduino banner covers a lot of programmable hardware, and it is a powerful tool in a hardware hacker’s belt. Two, someone saw a tool they wanted to control and made it happen. Three, it’s a piece of (minimal) security hardware, but who knows where that can scale. The secure is made accessible.

The Github upload instructions are illustrated, and you know we appreciate documentation. There are a couple of tables for the controller pins and header for your convenience. You will be compiling your sketch in Arduino’s IDE, but uploading through ST-Link across some wires you will have to solder. We are in advanced territory now, but keep this inspiration train going and drop us a tip to share something you make with this miniature deadbolt.

Locks and security are our bread and butter, so enjoy some physical key appreciation and digital lock love.

Hands On With A Batteryless E-Paper Display

June 17, 2020 by Donald Papp 64 Comments

E-paper displays are unusual in that power is only needed during a screen update. Once the display’s contents have been set, no power whatsoever is required to maintain the image. That’s pretty nifty. By making the display driver board communicate wirelessly over near-field communication (NFC) — which also provides a small amount of power — it is possible for this device to be both wireless and without any power source of its own. In a way, the technology required to do this has existed for some time, but the company Waveshare Electronics has recently made easy to use options available for sale. I ordered one of their 2.9 inch battery-less NFC displays to see how it acts.

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New Part Day: Battery-Less NFC E-Paper Display

March 22, 2020 by Erin Pinheiro 30 Comments

Waveshare, known for e-ink components aimed at hobbyists among other cool parts, has recently released a very interesting addition to their product line. This is an enclosed e-ink display which gets updated over a wireless NFC connection. By that description, nothing head-turning, but the kicker is that there is no battery inside the device at all, as it harvests the energy needed from the wireless communication itself.

Just like wireless induction charging in certain smartphones, the communication waves involved in NFC can generate a small current when passing through a coil, located on this device’s PCB. Since microcontrollers and e-ink displays consume a very small amount of current compared to other components such as a backlit LCD or OLED display, this harvested passive energy is enough to allow the display to update. And because e-paper requires no power at all to retain its image, once the connection is ended, no further battery backup is needed.

The innovation here doesn’t come from Waveshare however, as in 2013 Intel had already demoed a very similar device to promising results. There’s some more details about the project, but it never left the proof of concept stage despite being awarded two best paper awards. We wonder why it hadn’t been made into a commercial product for 5 years, but we’re glad it’s finally here for us to tinker with it.

E-paper is notorious for having very low refresh rates when compared to more conventional screens, much more so when driven in this method, but there are ways to speed them up a bit. Nevertheless, even when used as designed, they’re perfectly suited for being used in clocks which are easy on the eyes without a glaring backlight.

[Thanks Steveww for the tip!]