Meshtastic: A Tale Of Two Cities

If I’m honest with myself, I don’t really need access to an off-grid, fault-tolerant, mesh network like Meshtastic. The weather here in New Jersey isn’t quite so dynamic that there’s any great chance the local infrastructure will be knocked offline, and while I do value my privacy as much as any other self-respecting hacker, there’s nothing in my chats that’s sensitive enough that it needs to be done off the Internet.

But damn it, do I want it. The idea that everyday citizens of all walks of life are organizing and building out their own communications network with DIY hardware and open source software is incredibly exciting to me. It’s like the best parts of a cyberpunk novel, without all the cybernetic implants, pollution, and over-reaching megacorps. Well, we’ve got those last two, but you know what I mean.

Meshtastic maps are never exhaustive, but this gives an idea of node density in Philly versus surrounding area.

Even though I found the Meshtastic concept appealing, my seemingly infinite backlog of projects kept me from getting involved until relatively recently. It wasn’t until I got my hands on the Hacker Pager that my passing interest turned into a full blown obsession. But it’s perhaps not for the reason you might think. Traveling around to different East Coast events with the device in my bag, it would happily chirp away when within range of Philadelphia or New York, but then fall silent again once I got home. While I’d get the occasional notification of a nearby node, my area had nothing like the robust and active mesh networks found in those cities.

Well, they say you should be the change you want to see in the world, so I decided to do something about it. Obviously I wouldn’t be able to build up an entire network by myself, but I figured that if I started standing up some nodes, others might notice and follow suit. It was around this time that Seeed Studio introduced the SenseCAP Solar node, which looked like a good way to get started. So I bought two of them with the idea of putting one on my house and the other on my parent’s place down the shore.

The results weren’t quite what I expected, but it’s certainly been an interesting experience so far, and today I’m even more eager to build up the mesh than I was in the beginning.

Continue reading “Meshtastic: A Tale Of Two Cities”

Reshaping Eyeballs With Electricity, No Lasers Or Cutting Required

Glasses are perhaps the most non-invasive method of vision correction, followed by contact lenses. Each have their drawbacks though, and some seek more permanent solutions in the form of laser eye surgeries like LASIK, aiming to reshape their corneas for better visual clarity. However, these methods often involve cutting into the eye itself, and it hardly gets any more invasive than that.

A new surgical method could have benefits in this regard, allowing correction in a single procedure that requires no lasers and no surgical cutting of the eye itself. The idea is to use electricity to help reshape the eye back towards greater optical performance.

Continue reading “Reshaping Eyeballs With Electricity, No Lasers Or Cutting Required”

Smart Bulbs Are Turning Into Motion Sensors

If you’ve got an existing smart home rig, motion sensors can be a useful addition to your setup. You can use them for all kinds of things, from turning on lights when you enter a room, to shutting off HVAC systems when an area is unoccupied. Typically, you’d add dedicated motion sensors to your smart home to achieve this. But what if your existing smart light bulbs could act as the motion sensors instead?

Continue reading “Smart Bulbs Are Turning Into Motion Sensors”

Airbags, And How Mercedes-Benz Hacked Your Hearing

Airbags are an incredibly important piece of automotive safety gear. They’re also terrifying—given that they’re effectively small pyrotechnic devices that are aimed directly at your face and chest. Myths have pervaded that they “kill more people than they save,” in part due a hilarious episode of The Simpsons. Despite this, they’re credited with saving tens of thousands of lives over the years by cushioning fleshy human bodies from heavy impacts and harsh decelerations.

While an airbag is generally there to help you, it can also hurt you in regular operation. The immense sound pressure generated when an airbag fires is not exactly friendly to your ears. However, engineers at Mercedes-Benz have found a neat workaround to protect your hearing from the explosive report of these safety devices. It’s a nifty hack that takes advantage of an existing feature of the human body. Let’s explore how air bags work, why they’re so darn loud, and how that can be mitigated in the event of a crash.

Continue reading “Airbags, And How Mercedes-Benz Hacked Your Hearing”

On 3D Scanners And Giving Kinects A New Purpose In Life

The concept of a 3D scanner can seem rather simple in theory: simply point a camera at the physical object you wish to scan in, rotate around the object to capture all angles and stitch it together into a 3D model along with textures created from the same photos. This photogrammetry application is definitely viable, but also limited in the sense that you’re relying on inferring three-dimensional parameters from a set of 2D images and rely on suitable lighting.

To get more detailed depth information from a scene you’d need to perform direct measurements, which can be done physically or through e.g. time-of-flight (ToF) measurements. Since contact-free ways of measurements tend to be often preferred, ToF makes a lot of sense, but comes with the disadvantage of measuring of only a single spot at a time. When the target is actively moving, you can fall back on photogrammetry or use an approach called structured-light (SL) scanning.

SL is what consumer electronics like the Microsoft Kinect popularized, using the combination of a visible and near-infrared (NIR) camera to record a pattern projected onto the subject, which is similar to how e.g. face-based login systems like Apple’s Face ID work. Considering how often Kinects have been used for generic purpose 3D scanners, this raises many questions regarding today’s crop of consumer 3D scanners, such as whether they’re all just basically Kinect-clones.

Continue reading “On 3D Scanners And Giving Kinects A New Purpose In Life”

The Hottest Spark Plugs Were Actually Radioactive

In the middle of the 20th century, the atom was all the rage. Radiation was the shiny new solution to everything while being similarly poorly understood by the general public and a great deal of those working with it.

Against this backdrop, Firestone Tire and Rubber Company decided to sprinkle some radioactive magic into spark plugs. There was some science behind the silliness, but it turns out there are a number of good reasons we’re not using nuke plugs under the hood of cars to this day.

Continue reading “The Hottest Spark Plugs Were Actually Radioactive”

A Cut Above: Surgery In Space, Now And In The Future

In case you hadn’t noticed, we live in a dangerous world. While our soft, fleshy selves are remarkably good at absorbing kinetic energy and healing the damage that results, there are very definite limits to what we humans can deal with, beyond which we’ll need some help. Car crashes, falls from height, or even penetrating trauma such as gunshot wounds — events such as these will often land you in a trauma center where, if things are desperate enough, you’ll be on the operating table within the so-called “Golden Hour” of maximum survivability, to patch the holes and plug the leaks.

While the Golden Hour may be less of a hard limit than the name implies, it remains true that the sooner someone with a major traumatic injury gets into surgery, the better their chances of survival. Here on planet Earth, most urban locations can support one or more Level 1 trauma centers, putting huge swathes of the population within that 60-minute goal. Even in rural areas, EMS systems with Advanced Life Support crews can stabilize the severely wounded until they can be evacuated to a trauma center by helicopter, putting even more of the population within this protective bubble.

But ironically, residents in the highest-priced neighborhood in human history enjoy no such luxury. Despite only being the equivalent of a quick helicopter ride away, the astronauts and cosmonauts aboard the International Space Station are pretty much on their own when it comes to any traumatic injuries or medical emergencies that might crop up in orbit. While the ISS crews are well-prepared for that eventuality, as we’ll see, there’s only so much we can do right now, and we have a long way to go before we’re ready to perform surgery in space

Continue reading “A Cut Above: Surgery In Space, Now And In The Future”