Flying Defibrillators

July 11, 2017 by 57 Comments

It’s a sad reality that, by and large, cardiopulmonary resuscitation (CPR) doesn’t save lives. Despite all the “you could save a life” marketing aimed at getting people certified in CPR, the instances where even the prompt application of the correct technique results in a save are vanishingly rare, and limited mostly to witnessed arrests in a hospital. Speaking from personal experience, few things are sadder than arriving on-scene as a first responder to see CPR being performed by a husband on his wife and knowing that no matter what we do, it’s not going to end well.

The problem is one of time. Hearts only rarely just stop beating outright; usually some kind of arrhythmia first causes the heart to beat ineffectively, leading to hypoxia and loss of consciousness. From there it’s about a four-minute trip to brain death, but in that brief window chances are pretty good that the heart can be restarted. That’s why witnessed cardiac arrests in a hospital have better survival rates — the needed electric reboot of the heart with a defibrillator is only as far away as the nearest crash cart.

The advent of the automatic external defibrillator (AED) has increased the odds for survival of out-of-hospital cardiac arrest (OHCA), but the penetration of AEDs into public settings is far from complete enough to put one within a few minutes reach of everyone who might need one. So it’s only natural that thoughts would turn to delivering AEDs to cardiac incidents by drones. It seems like a great idea, but will it work? Continue reading “Flying Defibrillators” →

COSMAC Elf Calculator Gets New Firmware

July 11, 2017 by 18 Comments

Everyone remembers their first. Their first CPU, that is. For many of us, it was the RCA 1802 thanks to the COSMAC Elf articles that ran in Popular Electronics. The later versions of the chip family were much better but were never as popular, but the 1805 did find its way into a printing calculator for dimensions from a company named Boyd. Some of these recently showed up on the surplus market and–of course–were subsequently hacked.

[Bill Rowe] is active in the groups that still work with the 1802. Because of some specialized uses you can still get the chips readily, some four decades after they were new. Other computers at the time were difficult to build and relatively expensive, while for $100 almost anyone could wire wrap a simple 1802-based computer together in a weekend or less.

Continue reading “COSMAC Elf Calculator Gets New Firmware” →

Bicycle Racing In Space Could Be A Thing

July 11, 2017 by 100 Comments

It’s 2100 AD, and hackers and normals live together in mile-long habitats in the Earth-Moon system. The habitat is spun up so that the gravity inside is that of Earth, and for exercise, the normals cycle around on bike paths. But the hackers do their cycling outside, in the vacuum of space.

How so? With ion thrusters, rocketing out xenon gas as the propellant. And the source of power? Ultimately that’s the hackers’ legs, pedaling away at a drive system that turns two large Wimshurst machines.

Those Wimshurst machines then produce the high voltage needed for the thruster’s ionization as well as the charge flow. They’re also what gives the space bike it’s distinctly bicycle-like appearance. And based on the calculations below, this may someday work!

Continue reading “Bicycle Racing In Space Could Be A Thing” →

Automating Plant Care

July 11, 2017 by 15 Comments

[Daniyal]’s goal is to build an automated garden that allows him to grow plants in any environment he chooses. He’s got a good start with this rig, which is controlled by a Pi Zero connected via serial to an Arduino Mega clone, which  in turn controls a bank of relays and sensors.

Monitoring the environment is a temperature and humidity sensor as well as a series of  six soil moisture sensor spikes. The relays control the water pump(s?) and lights, allowing [Daniyal] to maintain specific conditions depending on what he’s growing.

[Daniyal] has ambitious goals for the project. The Pi has a camera on it, and he hopes to not only maintain the greenhouse from the Internet, but also figure out how to monitor plant growth automatically, so that the Pi can measure plant growth and adjust the conditions without his input.

We’ve covered a lot of very cool horticulture projects here on HaD, including radio-connected soil sensors, using G-cal to create an internet of lawns, and the Garden of Eden watering kit.

Smart pen

The Smart Pen

July 11, 2017 by 22 Comments

“Ugh. You mean I have to press down on the pen’s button to open it? Gross.” In this day-and-age when we can swipe on our phones and do voice recognition, there seems no reason we should have to press a button. How antiquated. So [Marek Baczynski] modernized his pen for swiping and voice control. It’s also sure to get all the kids back to working on their penmanship.

Seriously though, not all hacks have to be serious. [Marek] and [Ghlargh] added a servo to activate the button, and then [Marek] added Bluetooth to control the servo. After writing a phone app, he was able to swipe down to open it and down again to close it. Then, after some prompting from Redditers he added voice control from his laptop. We think he could have done a more professional job with the way he attached the pen to the laptop, perhaps he could have 3D printed something instead of just using tape, or maybe made something using CNC or a laser cutter. An important hack such as this deserves as much. Now he need only say “Computer. Open pen.” and the tedious task is taken care of. Seeing is believing so check it out in the video below.

Continue reading “The Smart Pen” →

Old Rabbit Ears Optimized For Weather Satellite Downlink

July 10, 2017 by 10 Comments

Communicating with a satellite seems like something that should take a lot of equipment. A fancy antenna and racks full of receivers, filters, and amplifiers would seem to be the entry-level suite of gear. But listening to a weather satellite with an old pair of rabbit ears and an SDR dongle? That’s a thing too.

There was a time when a pair of rabbit ears accompanied every new TV. Those days are gone, but [Thomas Cholakov (N1SPY)] managed to find one of the old TV dipoles in his garage, complete with 300-ohm twinlead and spade connectors. He put it to work listening to a NOAA weather satellite on 137 MHz by configuring it in a horizontal V-dipole arrangement. The antenna legs are spread about 120° apart and adjusted to about 20.5 inches (52 cm) length each. The length makes the antenna resonant at the right frequency, the vee shape makes the radiation pattern nearly circular, and the horizontal polarization excludes signals from the nearby FM broadcast band and directs the pattern skyward. [Thomas] doesn’t mention how he matched the antenna’s impedance to the SDR, but there appears to be some sort of balun in the video below. The satellite signal is decoded and displayed in real time with surprisingly good results.

Itching to listen to satellites but don’t have any rabbit ears? No problem — just go find a cooking pot and get to it.

Continue reading “Old Rabbit Ears Optimized For Weather Satellite Downlink” →

DEF CON BadgeLife: Blinky Bling

July 10, 2017 by 6 Comments

This is the biggest year yet for unofficial electronic conference badges. We’re calling it the year of Badgelife, and for the next few weeks, we’re going to be taking a look at the unofficial conference badges being deployed at this year’s DEF CON.

[Mr Blinky Bling] a.k.a. [Benn Hibben] has created his own badge for this year’s con. On board is a bunch of LEDs, WiFi, and capacitive buttons. It’s a WiFi badge for all your AP scanning and deauth needs. The electronics for this badge are a bit more complicated than simply throwing an ESP8266 on a board and calling the design done. The capacitive touch functionality is being handled by an ATTiny88, the OLED display is handled by an ATMega32U4, wireless functions are done with an ESP8266, and there are a few bits and bobs for a LiPo battery.

This WiFi Badge is the focus of an astonishingly successful Kickstarter (ending in just a few hours), and [Mr Blinky Badge] already has enough backers to move 200 badges. This is really a spectacular amount of work; it’s one thing to build a single prototype for an electronic conference badge, but it’s another matter entirely to put a badge into production, source all the parts, handle the assembly, and finally ship all these badges to Kickstarter backers and conference attendees.

If the challenge of building and deploying hundreds of electronic conference badges sounds like fun, you’re in luck. This Friday, we’ll be hosting a Hack Chat with some of the creators of this year’s unofficial DEF CON badge creators. There’s a lot you can learn from these folks, and a lot of very cool badges that will make an appearance at this year’s Def Con.