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Hackaday Links: September 12, 2021

The last thing an astronaut or cosmonaut on the International Space Stations wants to hear from one of their crewmates is, “Do you smell plastic burning?” But that’s apparently what happened this week aboard the increasingly problematic spacecraft, as the burning smell and visible smoke spread from the Russian Zvezda module to the American side of town. The reports say it occurred while charging the station’s batteries, and we all know how dicey that can get. But apparently, the situation resolved itself somehow, as normal operations continued soon after the event. Between reports of cracks, air leaks, problems with attitude control, and even accusations of sabotage, the ISS is really starting to show its age.

Speaking of burning and batteries, normally a story about burning Tesla batteries wouldn’t raise our eyebrows much. But this story out of California introduces a potential failure mode for Tesla batteries that we hadn’t considered before. It seems a semi-truck with a load of Tesla batteries lost its brakes on Interstate 80 in the Sierra Nevada mountains and ended up flipping across the highway. Video from the scene shows the cargo, which looks like replacement batteries or perhaps batteries salvaged from wrecked cars, scattered across the highway on their shipping pallets. A fire was reported, but it’s not clear whether it was one of the batteries which had gotten compromised in the crash, or if it was something other than the batteries. Still, we hadn’t considered the potential for disaster while shipping batteries like that.

Attention all GNURadio fans — GRCon21 is rapidly approaching. Unlike most of the conferences over the last year and half, GRCon21 will actually be both live and online. We always love the post-conference dump of talks, which cover such a wide range of topics and really dive deeply into so many cool areas. We’re especially looking forward to the SETI talks, and we’re pleased to see our friend Hash, who was on the Hack Chat a while back, scheduled to talk about his smart-meter hacking efforts. The conference starts on September 20 and is being held in Charlotte, North Carolina, and virtually of course. If you attend, make sure to drop tips to your favorite talks in the tips line so we can share them with everyone.

We got a tip this week on a video about how 1/4-wave tuning stubs work. It’s a simple demonstration using a length of coax, a signal generator, and an oscilloscope to show how an unterminated feedline can reflect RF back to the transmitter, and how that can be used to build super-simple notch filters and impedance transformers. We love demos that make the mysteries of RF a little simpler — W2AEW’s videos come to mind, like this one on standing waves.

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The Curious Case Of The Radio Amateur And The Insulin Pump

A substantial part of gaining and holding an amateur radio licence relates to the prevention of radio interference. In days past this meant interference to analogue television broadcasts, but with ever more complex devices becoming commonplace in homes it applies to much more. This has hit the news in Marion County Florida, where a radio amateur in a senior’s community has shut down his radio station after a potential link emerged between it and another resident’s insulin pump. There is a legal challenge ongoing that relates to the complex’s rules over transmitting antennas.

It’s obviously a serious occurrence for an insulin pump to be affected by anything, and it sounds as though the radio amateur concerned has done the right thing. But it’s clear that something has gone badly wrong in this case whether it’s due to the amateur radio transmissions or not, because for a manufacturer to produce a medical device so easily affected by RF fields should be of concern to everyone. We’d hope that the FCC might take an interest in this story and get to the bottom of it in an impartial manner, because whether it’s the radio amateur at fault, the insulin pump, or something else entirely, it presents a risk to anyone dependent upon such a device.

Perhaps this might also be a case for the ARRL, as we’ve reported before they have some form when it comes to radio investigations.

[Main image source: MailariX, CC-BY-SA 4.0]

Hacking Diabetes Hack Chat

Join us on Wednesday, October 16 at noon Pacific for the Hacking Diabetes Hack Chat with Dana Lewis!

When your child is newly diagnosed with Type 1 diabetes (T1D), everyone is quick to point out, “It’s a great time to be a diabetic.” To some degree, that’s true; thanks to genetically engineered insulin, more frequent or even continuous glucose monitoring (CGM), and insulin infusion pumps, diabetics can now avoid many of the truly terrifying complications of a life lived with chronically elevated blood glucose, like heart disease, kidney failure, blindness, and amputations.

Despite these advances, managing T1D can be an overwhelming task. Every bite of food, every minute of exercise, and every metabolic challenge has to be factored into the calculations for how much insulin to take. Diabetics learn to “think like a pancreas,” but it’s never good enough, and the long-promised day of a true artificial pancreas always seems to remain five years in the future.

Dana Lewis is one diabetic who decided not to wait. After realizing that she could get data from her CGM, she built a system to allow friends and family to monitor her blood glucose readings remotely. With the addition of a Raspberry Pi and some predictive algorithms, she later built an open-source artificial pancreas, which she uses every day. And now she’s helping others take control of their diabetes and build their own devices through OpenAPS.org.

Join us on the Hack Chat as Dana drops by to discuss OpenAPS and her artificial pancreas. We’ll find out what her background is – spoiler alert: she wasn’t a hacker when she started this – what challenges she faced, the state of the OpenAPS project, and where she sees the artificial pancreas going.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, October 16 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

[Dana Lewis image source: GeekWire]

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Reverse Engineering An Insulin Pump With An SDR And Decapping

Insulin pumps are a medical device used by people with diabetes to automatically deliver a measured dose of insulin into their bloodstream. Traditionally they have involved a canula and separate connected pump, but more recent models have taken the form of a patch with a pump mounted directly upon it. When [Pete Schwamb]’s daughter received  one of these pumps, an Omnipod, he responded to a bounty offer for reverse engineering its RF protocol. As one of the people who helped create Loop, an app framework for controlling insulin delivery systems, he was in a particularly good position to do the work.

The reverse engineering itself started with the familiar tale of using an SDR to eavesdrop on the device’s 433MHz communication between pump and control device. Interrogating the raw data was straightforward enough, but making sense of it was not. There was a problem with the CRC algorithm used by the device which had a bug involving a bitwise shift in the wrong direction, then they hit a brick wall in the encryption of the data. Hardware investigation revealed a custom chip in the device, and there they might have stalled.

But the international reverse engineering community is not without resources and expertise, and through the incredible work of a university researcher in the UK (whose paper incidentally includes a pump teardown) they were able with an arduous process supported by many people to have the firmware recovered through decapping the chip. Even once they had thus extracted the encryption code and produced their own software their problems were not over, because communication issues necessitated a much better antenna on the RileyLink Bluetooth bridge boards that translated Bluetooth from a mobile phone to 433 MHz for the device.

This precis doesn’t fully encapsulate the immense amount of work over several years by a large group of people with some very specialist skills that reverse engineering the Omnipod represents. To succeed in this task is an incredible feat, and makes for a fascinating write-up.

Thanks [Alex] for the tip.

Homebrew Pancreas Gets 30 Minutes Of Fame

It is pretty unusual to be reading Bloomberg Businessweek and see an article with the main picture featuring a purple PCB (the picture above, in fact). But that’s just what we saw this morning. The story is about an open source modification to an insulin pump known as the RileyLink. This takes advantage of older Medtronic brand insulin pumps and allows you to control the BLE device from a smartphone remotely and use more sophisticated software to control blood sugar levels.

Of course, the FDA isn’t involved. If they were, the electronics would cost $7,000 instead of $250 — although, in fairness, that $250 doesn’t cover the cost of the used pump. Why it has to be a used pump is a rather interesting story. The only reason the RileyLink is possible is due to a security flaw and an active hacker community.

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