Alzheimer’s disease remains a frustratingly difficult condition to manage for the millions of patients affected worldwide and their families. The cause of the disease is still not properly understood, and by the time memory loss and cognitive decline become apparent, the underlying brain pathology has often been quietly building for decades.
Cryptography is a funny thing. Supposedly, if you do the right kind of maths to a message, you can send it off to somebody else, and as long as they’re the only one that knows a secret little thing, nobody else will be able to read it. We have all sorts of apps for this, too, that are specifically built for privately messaging other people.
Only… sometimes just having such an app is enough to get you in trouble. Even just the garbled message itself could be proof against you, even if your adversary can’t read it. Enter The Guardian. The UK-based media outlet has deployed a rather creative and secure way of accepting private tips and information, one which seeks to provide heavy cover for those writing in with the hottest scoops.
Light aircraft often use a heading indicator as a way to know where they’re going. Retired instrumentation engineer [Don Welch] recreated a heading indicator of his own, using cheap off-the-shelf hardware to get the job done.
The heart of the build is a Teensy 4.0 microcontroller. It’s paired with a BNO085 inertial measurement unit (IMU), which combines a 3-axis gyro, 3-axis accelerometer, and 3-axis magnetometer into a single package. [Don] wanted to build a heading indicator that was immune to magnetic disturbances, so ignored the magnetometer readings entirely, using the rest of the IMU data instead.
Upon startup, the Teensy 4.0 initializes a small round TFT display, and draws the usual compass rose with North at the top of the display. Any motion after this will update the heading display accordingly, with [Don] noting the IMU has a fast update rate of 200 Hz for excellent motion tracking. The device does not self-calibrate to magnetic North; instead, an encoder can be used to calibrate the device to match a magnetic compass you have on hand. Or, you can just ensure it’s already facing North when you turn it on.
Thanks to the power of the Teensy 4.0 and the rapid updates of the BNO085, the display updates are nicely smooth and responsive. However, [Don] notes that it’s probably not quite an aircraft-spec build. We’ve featured some interesting investigations of just how much you can expect out of MEMS-based sensors like these before, too.
The end table was built from scratch, with [Peter] going through all the woodworking steps required to assemble the piece. The three-legged wooden table is topped with a tiny N-scale model railway layout, and you get to see it put together including the rocks, the grass, and a beautiful epoxy river complete with a bridge. The railway runs a Kato Pocket Line trolley, but the really neat thing is how it’s powered.
[Peter] shows us how a small gearmotor generator was paired with a bridge rectifier and a buck converter to fill up a super capacitor that runs the train and lights up the tree on the table. Just 25 seconds of cranking will run the train anywhere from 4 to 10 minutes depending on if the tree is lit as well. To top it all off, there’s even a perfect coaster spot for [Peter]’s beverage of choice.
The device under test is a Boss ME-50 multi-effects unit. It’s capable of serving up a wide range of effects, from delay to chorus to reverb, along with compression and distortion and a smattering of others. [Liam] hooked up the composite video output from an old Sony camcorder from the 2000s to a 3.5 mm audio jack, and plugged it straight into the auxiliary input of the ME-50 (notably, not the main guitar input of the device).
The multi-effects pedal isn’t meant to work with an analog video signal, but it can pass it through and do weird things to it regardless. Using the volume pedal on the ME-50 puts weird lines on the signal, while using a wah effect makes everything a little wobbly. [Liam] then steps through a whole range of others, like ring modulation, octave effects, and reverb, all of which do different weird things to the visuals. Particularly fun are some of the periodic effects which create predictable variation to the signal. True to its name, the distortion effect did a particularly good job of messing things up overall.
Old desk phones are fairly useless these days unless you’re building a corporate PBX in your house. However, they can be fun to hack on, as [0x19] demonstrates by porting DOOM to a Snom 360 office phone.
The Snom 360 is a device from the early VoIP era, with [ox19] laying their hands on some examples from 2005. The initial plan was just to do some telephony with Asterisk, but [ox19] soon realized more was possible. Digging into a firmware image revealed the device ran a Linux kernel on a MIPS chip, so the way forward became obvious.
They set about hacking the phone to run DOOM on its ancient single-color LCD. Doing so was no mean feat. It required compilation of custom firmware, pulling over a better version of BusyBox, and reworking doomgeneric to run on this oddball platform. It also required figuring out how the keyboard was read and the screen was driven to write custom drivers—not at all trivial things on a bespoke phone platform. With all that done, though, [0x19] had a dodgy version of DOOM running slowly on a desk phone on a barely-legible LCD display.
Porting DOOM is generally a task done more for the technical thrill than to actually play the game on terribly limited hardware. We love seeing it done, whether the game is ported to a LEGO brick or a pair of earbuds. If you’re doing your own silly port, don’t hesitate to notify the tipsline—just make sure it’s one we haven’t seen before.
If you’ve ever used a ballpoint pen with a clip on the top, you’ve probably noticed they bend pretty easily. The clip relies on you only bending it a small amount to clip it on to things; bend it too far, and it ends up permanently deformed. [Craighill] decided to develop a pen clip that didn’t suffer this ugly malady.
The wire clip design easily opens wide because the spring wire is not actually deforming much at all. Credit: YouTube video, via screenshot
The problem with regular pen clips comes down to simple materials science. Bend the steel clip a little bit, and the stress in the material remains below the elastic limit—so it springs back to its original shape. Push it too far, though, and you’ll end up getting into the plastic deformation region, where you’ve applied so much stress that the material is permanently deformed.
[Craighill] noted this problem, and contemplated whether a better type of clip was possible. An exploration of carabiner clips served to highlight possible solutions. Some carabiners using elastically-deformed closures that faced the same problem, while others used more complicated spring closures or a nifty bent-wire design. This latter solution seemed perfect for building a non-deforming pen clip. The bent wire is effectively a small spring, which allows it to act as a clip to hold the pen on to something. However, it’s also able to freely rotate out from the pen body, limiting the amount of actual stress put on the material itself, which stops it entering the plastic deformation region that would ruin it.
It’s some neat materials science combined with a pleasant bit of inventing, which we love to see. Sometimes there is joy to be had in contemplating and improving even the simplest of things. Video after the break.
