Empanada Becomes Impractical, Delicious Synth

April 1, 2020 by Lewin Day 20 Comments

Vegemite is an Australian staple – a rich, protein-filled sandwich spread with a strong salty flavor. It serves as a great way to add a little umami to any dish, which is the hottest open secret in Australian cuisine this decade. It also works as a servicable conductive paint, which [Alex] used to make this baked good into a musical device.

The basis of the device is a basic audio example sketch running on an Adafruit Circuit Playground Express. The code was tweaked to play a 7-note C major scale. The PCB was then attached to the empanada with toothpicks through each pad, with the baked good itself seemingly connected to the ground plane. The toothpicks through the pads were then coated with Vegemite, and another toothpick treated the same way and used as a stylus. By touching the toothpick to the empanada and one of the pads, the circuit is made, and a note is played.

It’s an impractical way to go about musical performance, sure. But it is an effective demonstration of foodstuffs used in electronics. Calvin Harris did much the same back in 2009, albeit with humans substituting for the delicious pastry. Video after the break.

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Professional Ventilator Design Open Sourced Today By Medtronic

March 30, 2020 by Bob Baddeley 116 Comments

Medical device company Medtronic released designs for one of their ventilators to open source for use in the COVID-19 pandemic. This is a laudable action, and there is plenty to glean from the specs (notable is that the planned release is incomplete as of this writing, so more info is on the way). Some initial reactions: medical devices are complicated, requirements specifications are enormous, the bill of materials (BOM) is gigantic, and component sourcing, supply chain, assembly, and testing are just as vital as the design itself.

The pessimist in me says that this design was open sourced for two reasons; to capitalize on an opportunity to get some good press, and to flex in front of the DIY community and convince them that the big boys should be the ones solving the ventilator shortage. The likelihood of anyone actually taking these specs and building it as designed are essentially zero for a variety of reasons, but let’s assume their intent is to give a good starting point for newer changes. The optimist in me says that after what happened to California over the weekend with 170 ventilators arriving broken, it might be nice to have open designs to aid in repair of existing non-functioning ventilators.

The design details released today are for their PB560 model, which was originally launched in 2010 by a company called Covidien, before it merged with Medtronic, so we’re already starting with a device design that’s a decade old. But it’s also a design that has proven itself through widespread use, and this data dump gives us a great look at what actually goes into one of these machines. Let’s take a look.

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Coronavirus Testing Follow-Up: Rapid Immunologic Testing

March 30, 2020 by Dan Maloney 12 Comments

When I started writing my recent article on COVID-19 testing, I assumed that I would be doing a compare and contrast sort of article. Like many people, I assumed that the “gold standard” test would be the reverse transcriptase-polymerase chain reaction (RT-PCR) test that I described in some detail. And indeed it is, but it’s not without its problems, such as the lack of certified labs and the need for trained technicians to run the samples. I also assumed there would be another test, a simple serological test that could use antibodies to discern if there was an active or even a previous, resolved infection.

At the time I wrote the first article, I could find no indication of an immunologic test for COVID-19 (more specifically, a test for SARS-Cov-2, the virus that causes COVID-19). But almost as rapidly as the number of COVID-19 cases rises, the news changes, and it appears that simple, rapidly performed antibody tests are now or soon will be available. They likely won’t replace the gold standard RT-PCR test, but they do stand to be a game-changer for the front line providers and the victims of this disease. So it pays to take a quick look at immunoassays for infectious diseases, and learn how they work.

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Poor Maintenance Could Have Led To Fatal B-17 Crash

March 28, 2020 by Tom Nardi 49 Comments

In October the Nine-O-Nine, a fully restored Boeing B-17G bomber owned and operated by the Collings Foundation, crashed with thirteen people on board. After landing hard and skidding into the de-icing tanks at the Bradley International Airport, all but the tail and port wing of the 74 year old WWII aircraft was destroyed. Seven lives were lost in the accident, including that of Pilot Ernest “Mac” McCauley, who was regarded as one of the most experienced B-17 pilots in the world.

While the National Transportation Safety Board (NTSB) investigation is still ongoing and hasn’t made a final determination as to what ultimately brought down the Nine-O-Nine, enough serious maintenance issues were uncovered while examining the wreckage that the Federal Aviation Administration (FAA) has decided to rescind the Collings Foundation’s license to conduct any more paid flights on their remaining WWII aircraft. While many have spoken out in support of these “living history” flights, the FAA says they must be conducted in such a way that they don’t hinder the safety of other air traffic.

With the vast majority of the B-17’s airframe gone, the NTSB investigation has focused on the four 1,200 horsepower Wright R-1820 “Cyclone” engines recovered from the crash site. Investigators found that hastily attempted repairs to engine number 4, which is believed to have failed in-flight, were actually hindering normal operation:

Regarding engine 4, to prevent the magneto “P” leads from separating from the
magnetos, someone had attempted to rig the magneto leads in place with safety wire.

Inspection and testing of engine 4 left magneto revealed the movement of the safety-wired lead caused grounding to the case, which rendered the magneto lead inoperative.

Further, all of the spark plugs in the number 3 and 4 engines were found to be fouled and had electrode gaps that were out of tolerance. From an examination of the aircraft’s maintenance records, it was also learned that an arcing and burned wire had been replaced without any investigative steps taken to find what caused the failure to begin with.

With basic maintenance tasks either not being performed or at least done incorrectly, the FAA has called into question the culture of safety at the Collings Foundation. The paper is careful not to directly accuse the Foundation or any of its staff with outright negligence, but the implication seems clear.

The loss of Nine-O-Nine hit especially close to home for Hackaday. Just a month prior to the crash we had the opportunity to tour the aircraft, and came away with a newfound respect for not only those who designed and built the iconic bomber but the brave young men who flew it. Losing such a rare and historically significant aircraft and its crew was already a tragedy, but to find that negligence may be to blame is truly inexcusable.

COVID-19 Statistics: Reading The Tea Leaves

March 28, 2020 by Elliot Williams 63 Comments

If you’ve been tracking the spread of the COVID-19 pandemic around the world, as we have, you’ve doubtless seen a lot of statistics. The raw numbers look shocking, and in many cases they are, but as always it’s crucially important to ask yourself what the numbers mean.

For instance, our own Tom Nardi put together a counter that displays the total number of COVID-19 cases in the US. It’s a cool project that puts together some web-scraping, a nice OLED screen, and a 3D-printed network display. When this is all over, it can be easily re-trained to show some other statistic of interest, and it’s a great introduction to a number of web APIs. However, it’s looking at the wrong number.

Let me explain. Diseases spread exponentially: the more people who have it, the more people are spreading it. And exponential curves all look the same when you plot out their instantaneous values — the raw number of COVID-19 cases. Instead, what distinguishes one exponential from another is the growth parameter, and this is related to the number of new cases per day, or more correctly, to the day-to-day change in new cases.

If left unchecked, and especially in the early stages of spread, the number of new cases grows every day. But as control efforts, mainly social distancing, take effect, the rate at which the number of new cases can slow, or even go negative. That’s the plan, anyway.

As is very well explained by this video from 3 Blue, 1 Brown, if this were a naturally spreading epidemic, the point at which the new cases just starts to decline marks the halfway point in the course of the disease. Here, we’re hoping that particularly strict quarantining procedures will cut this run even shorter, but if you’re interested in how the disease is spreading, the point when daily new infections turns around is what you’re looking for.

Why not put the daily difference in new cases on your desktop, then? These numbers are noisy, and the difference jumps all around. To be serious, you would probably want to put a moving average on the new cases figure, and look at that difference. Or simply show the new cases instead and look for it to drop for a few days in a row.

Still, this won’t be a perfect measure. For starters, COVID-19 seems to incubate for roughly a week without symptoms. This means that whatever numbers we have, they’re probably a week behind the actual situation. We won’t see the effects of social distancing for at least a week, and maybe more.

Further complicating things is the availability of tests, human factors like weekends when more people get tested but fewer government reporting offices are open, timezones, etc. (What happened on Feb. 13?)

I’m not going to go so far as to say that the COVID-19 stats that we see are useless — actually far from it. But if you’re going to armchair quarterback this pandemic, do it right. Plot out the daily new cases, maybe apply a little smoothing, at least in your head, and realize that whatever you’re seeing now probably represents what happened last week.

When you finally see the turning point, you may celebrate a little, because that means the halfway point was a week ago. We’ve seen it happen in China around Feb 2, and I’m looking forward to it happening here. I hope it happens wherever you are, and soon.

We will get through this. Stay safe, all. And keep yourself uninfected to keep others uninfected.

NASA Spinoff Prints Electronics

March 27, 2020 by Al Williams 20 Comments

NASA says that Electronic Alchemy’s eForge 3D printer is another space program spinoff. The printer looks a lot like a conventional 3D printer but unlike its mundane cousin it can print sensors, lights, and other electronic components. It does that by using one of six or eight different materials.

Six of the eight spools each have some sort of electronic property. According to the company they have conductive filament, resistive filament, insulating filament, capacitive filament, and both N- and P-type semiconductors.

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This Week In Security: 0-Days, Pwn2Own, IOS And Tesla

March 27, 2020 by Jonathan Bennett 4 Comments

LILIN DVRs and cameras are being actively exploited by a surprisingly sophisticated botnet campaign. There are three separate 0-day vulnerabilities being exploited in an ongoing campaigns. If you have a device built by LILIN, go check for firmware updates, and if your device is exposed to the internet, entertain the possibility that it was compromised.

The vulnerabilities include a hardcoded username/password, command injection in the FTP and NTP server fields, and an arbitrary file read vulnerability. Just the first vulnerability is enough to convince me to avoid black-box DVRs, and keep my IP cameras segregated from the wider internet.

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