Reverse Engineering Hack Chat With Matthew Alt

Join us on Wednesday, September 28 at noon Pacific for the Reverse Engineering Hack Chat with Matthew Alt!

Our world is full of mysteries, from the nature of time to how exactly magnets work. There are some things that we just have to accept that no matter how hard we look, we’ll never get a complete answer, especially in the natural world. The constructed world is another thing, though. It doesn’t seem fair that only a relatively few people have the inside scoop on the workings of everyday things, like network routers, game consoles, and even the vehicles we drive. Of course, the companies that make these things have a right to profit from their intellectual property, but we as consumers also have a right to be curious about how these things work and to understand what the software running on these devices is doing on our behalf.

join-hack-chatLuckily, what can be engineered can be reverse engineered, if you have the right tools and the skills to use them. It can be a challenge, but it’s one Matthew Alt has taken on plenty of times. We’ve seen him deep-dive into JTAG, look at serial wire debugging, and recently even try some glitching attacks. In fact, he even taught a HackadayU course on reverse engineering with Ghidra. And now he’ll drop by the Hack Chat to talk all about reverse engineering. Join us with your questions, your exploits, and your ideas on how to go where no hacker has gone before.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, September 28 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Probably The Simplest Radiation Detector You Already Own

Over the years we’ve featured quite a few radiatioactivity detectors, which usually include a Geiger-Muller tube, or perhaps a large-area photodiode. But in the event of radiation exposure from a nuclear attack, how does the man in the street gauge the exposure without owning a dedicated instrument? This was a question of note at the height of the Cold War, and it’s one that [Dr. Marshall Brucer] answered in a 1962 paper entitled “When Do You Leave A Fallout Shelter“. The full paper is behind a paywall but the part we’re interested in is on the freely available first page.

Dr. Brucer‘s detector is simplicity itself, and it relies on the erosion of a static electric charge by radiation. Should you rub a plastic comb in your hair it will accumulate enough charge to pick up a small piece of paper, and under normal background radiation the charge will ebb away such that it will drop the piece of paper after about 15 seconds. His calculation is that once the field reaches around 10 roentgens per hour it will be enough to erase the charge and drop the paper immediately. There’s a comtemporary newspaper report (Page 7, just to the left of the large advertisment) which tells the reader that since the exposure limit is 100 roentgens (one sievert), this test failing indicates that they have nine hours to create a better shelter. For obvious reasons we can’t test this at the Hackaday bench, but those of us who remember the days when such topics were a real concern will be searching for a handy comb anyway.

Thanks [Victor Matthew] for the tip.

Smart Pills Can Tell Your Doctor That You’ve Taken Them

We have many kinds of pills available these days to treat all kinds of different disorders. Of course, the problem with pills is that they don’t work if you don’t take them. Even Worse, for some medicines, missing a dose can cause all kinds of undesirable withdrawl effects and set back a patient’s treatment.

Smart pills aim to fix this problem with a simple monitoring solution that can tell when a patient has taken their medication. They’re now publicly available and authorized for use, so let’s look at how they work.

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So How Do You Make A Self-Destructing Flash Drive?

A self-destructing storage device that vaporizes its contents at the first sign of trouble would be an invaluable tool for many people, but good luck getting your hands on such a thing if you don’t work for a three-letter agency. Or at least, that’s what we would have said before [Walker] got on the case. He’s working on an open source self-destructing USB flash drive for journalists, security researchers, whistleblowers, or anyone else who really values their privacy.

When we previously covered this project in July, [Walker] had only planned to make the flash drive hide its contents unless you knew to wet your fingers before plugging it in. We admit it sounds a little weird, but as far as clandestine methods of activating something goes, it’s pretty clever. But based on the feedback he received, he decided to go all-in and make the USB drive literally trash itself should it be accessed by somebody who doesn’t know the secret.

An elegant weapon for a more civilized age.

But how exactly do you pull that off? Sure we’d love to see a small thermite charge or vial of acid packed in there, but obviously that’s not very practical. It needs to be safe to carry around, and just as importantly, unlikely to get you into even more trouble with whoever is searching through your belongings. To that end, [Walker] thinks he’s come up with an elegant solution.

The datasheet for his flash memory chip says the maximum voltage it can handle before releasing the Magic Smoke is a meager 4.6 V. So he figures running a voltage doubler on the nominal 5 V coming from a USB port should disable the chip nicely with a minimum of external drama. Will it be enough to prevent the data from being recovered forensically? We don’t know, but we’re eager to find out.

In the write-up, [Walker] takes readers through the circuit designs he’s come up so far, and shows off the source code that will run on the ATtiny25 to determine when it’s time to toast the flash. He says by the next post he should have the entire flash drive built and documented, so stay tuned.

three sensory bridge audio spectrum analyzers, one in use with a lit LED array plugged in, the other facing the camera and leaning against the third, all on a table

The Sensory Bridge Is Your Path To A Desktop Rave

[Lixie Labs] are no strangers to creating many projects with LEDs or other displays. Now they’ve created a low latency music visualizer, called the Sensory Bridge, that creates gorgeous light shows from music.

The Sensory Bridge has the ability to update up to 128 RGB LEDs at 60 fps. The unit has an on-board MEMS microphone that picks up ambient music to produce the light show. The chip is an ESP32-S2 that does Fast Fourier Transform trickery to allow for real-time updates to the RGB array. The LED terminal supports the common WS2812B LED pinouts (5 V, GND, DATA). The Sensory Bridge also has an “accessory port” that can be used for hardware extensions, such as a base for their LED “Mini Mast”, a long RGB array PCB strip.

The unit is powered by a 5 V 2 A USB-C connector. Different knobs on the device adjust the brightness, microphone sensitivity and reactivity of the LED strip. One of the nicer features is its “noise calibration” that can record ambient sound and subtract off the background noise frequency components to give a cleaner music signal. The Sensory Bridge is still new and it looks like some of the features are yet to come, like WiFi communication, accessory port upgrades and 3.5 mm audio input to bypass the on-board microphone.

The stated goals of the Sensory Bridge are to provide an open, powerful and flexible platform. This can be seen with their commitment to releasing the project as open source hardware, providing firmware, PCB design files and even the case STLs under a libre/free license. Audio spectrum analyzers are a favorite of ours and we’ve seen many different iterations ranging from ones using Raspberry Pis to others use ESP32s.

Video after the break!

Continue reading “The Sensory Bridge Is Your Path To A Desktop Rave”