Month: November 2017

Sferics, Whistlers, And The Dawn Chorus: Listening To Earth Music On VLF

November 6, 2017 by 19 Comments

We live in an electromagnetic soup, bombarded by wavelengths from DC to daylight and beyond. A lot of it is of our own making, especially further up the spectrum where wavelengths are short enough for the bandwidth needed for things like WiFi and cell phones. But long before humans figured out how to make their own electromagnetic ripples, the Earth was singing songs at the low end of the spectrum. The very low frequency (VLF) band abounds with interesting natural emissions, and listening to these Earth sounds can be quite a treat.

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Evil Hotspot Costume Makes Valuable Connections

November 6, 2017 by 14 Comments

This year for Hallowe’en, [Scott] went out dressed as a Comcast xfinity hotspot. Funny, yes, but there’s a deeper meaning here. [Scott] really went as a walking PSA that illustrates the dangers of making assumptions about the relative safety of WiFi networks based solely on their broadcast names.

[Scott] could have gone chaotic evil with this setup, but he didn’t. No one could actually get on the Internet through him. Inside the “hotspot” are a Wi-Fi adapter and a Pi Zero running a captive portal. It broadcasts the default ‘XFINITY’ and ‘xfinitywifi’ SSIDs, plus a bunch of other common network names. Whenever anyone tries to connect, or worse, their phone automatically connects, they’ll hear a sad tuba cadence. This comes courtesy of a multi-sound effects box that’s controlled by the Pi through a relay board.

Meanwhile, the mark’s device is redirected to an internally-hosted “xfinity” login page. Anyone who actually goes on to enter their login credentials is treated to a classic horror film scream sample while the evil hotspot quietly stores their name and password and displays them on an e-ink display for all to see — a walking e-ink wall of sheep. Check out the demo after the break.

[Scott]’s evil hotspot is powered by a huge battery that can run it for 24 hours. Here’s a wind- and solar-powered WAP we covered several years ago.

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How Pure Is This Cup Of Joe? Coffee, Conspiracy, And Citizen Science

November 6, 2017 by 38 Comments

Have you ever thought about coffee purity? It’s more something you’d encounter with prescription or elicit drugs, but coffee is actually a rather valuable commodity. If a seller can make the actual grounds go a bit further by stretching the brew with alternative ingredients there becomes an incentive to cheat.

If this sounds like the stuff rumors are made of, that’s because it is! Here in Ho Chi Minh City there are age-old rumors a coffee syndicate that masterfully passes off adulterated product as pure, high-grade coffee. Rumors are one thing, but the local media started picking up on these suspicions and that caught my attention. I decided to look to simple chemistry to see if I could prove or disprove the story.

What we want to investigate is whether price and coffee purity are related. If they are, then after accounting for the effect of price, we will want to know whether proximity to the market where artificial coffee flavoring is sold has an effect on coffee purity.

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Reverse Engineering The Nintendo Switch Joy-Cons

November 6, 2017 by 26 Comments

The Switch is Nintendo’s latest effort in the console world. One of its unique features is the Joy-Cons, a pair of controllers that can either attach directly to the console’s screen or be removed and used individually. But how do they work? [dekuNukem] decided to find out.

The reverse engineering efforts begin with disassembly. Surprisingly, there is no silkscreen present on the board to highlight test points or part numbers. This is likely to conflate intended to stymie community efforts to work with the hardware, as different teams may create their own designations for components. Conversely, the chips inside still have their identifying markings present, which does ease identification somewhat.

There are some interesting choices made – the majority of the buttons are scanned in a matrix configuration by the on-board microcontroller, making it harder to spoof button presses. The controllers communicate over Bluetooth, switching to a physical serial connection when attached directly to the screen. This runs at a blistering 3,125,000 BPS after the initial handshake is completed.

Overall it’s a fairly comprehensive reverse engineering effort, and [dekuNukem] has provided excellent detail in the writeup for anyone else looking to get involved. There’s still some work left to do, like investigating the rumble messages, but it’s an excellent start and very comprehensive.

Perhaps you’re more interested in older Nintendo hardware? Check out this comprehensive effort to figure out NES console-to-cartridge security methods.

Turn Medical Imaging From 2D Into 3D With Just $10

November 6, 2017 by 48 Comments

One of the modern marvels in our medical toolkit is ultrasound imaging. One of its drawbacks, however, is that it displays 2D images. How expensive do you think it would be to retrofit an ultrasound machine to produce 3D images? Try a $10 chip and pennies worth of plastic.

While — of all things — playing the Wii with his son, [Joshua Broder, M.D], an emergency physician and associate professor of surgery at [Duke Health], realized he could port the Wii’s gyroscopic sensor to ultrasound technology. He did just that with the help of [Matt Morgan, Carl Herickhoff and Jeremy Dahl] from [Duke’s Pratt School of Engineering] and [Stanford University]. The team mounted the sensor onto the side of the probe with a 3D printed collar. This relays the orientation data to the computer running software that sutures the images together into a complete 3D image in near real-time, turning a $50,000 ultrasound machine into its $250,000 equivalent.

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Twin Pis For Remote Computer Management

November 5, 2017 by 32 Comments

Sometimes you have a whole bunch of computers that you need to work with, and having a keyboard, monitor, and mouse for each one becomes too much to deal with. There are a multitude of solutions to this problem, but [Fmstrat] went the hacker route, and built their own.

The build is a rather unique way of controlling PCs remotely, but it does the job. A Raspberry Pi 3 is pressed into service as the core of the operation. It’s accessible over IP for remote control. Video is captured from the controlled machines through the combination of an HDMI-to-S-Video adapter and an analog video capture card plugged into the Pi. Keystrokes are sent in a roundabout way, first sent to a Pi Zero over a USB-to-Serial adapter. From there, the Pi acts as an emulated mouse and keyboard to the PC under control.

One caveat of remotely controlling computers over a network is that if things go pearshaped, it can become necessary to power cycle the machine. [Fmstrat] deals with this by fitting a relay board to the Pi 3, which is connected to the reset buttons of the machines under control.

It may not be the quickest, easiest, or industry standard way of controlling remote computers, but it works. [Fmstrat] tells us this build was primarily designed to get around the fact that there aren’t any decent cheap IP-KVM systems, and consumer motherboards don’t support the IPMI standard that would otherwise be useful here.

We particularly like the hard-wired relays for rebooting a machine – great for when a network dropout is stopping Wake-on-LAN packets from achieving their goal. While the conversion of HDMI outputs into analog video for capture is unusual and somewhat costly on a per-machine basis, it’s functional and gives the system the ability to work with any machine capable of outputting a basic analog video signal. With the Pi Zero keyboard emulation and analog video capture, we could see this being used with everything from modern computers to vintage 80s hardware. If you’ve ever needed to control an Amiga 2000 remotely for whatever reason, this could be the way to do it.

We’ve seen plenty of other KVM builds over the years, too – like this low-cost HDMI switcher.

Programming An Oscilloscope Breakout Game In Pure Data

November 5, 2017 by 3 Comments

[S-ol] wrote in to share his sweet breakout game played on an oscilloscope. Built in a weekend as part of a game development jam, Plonat Atek is a polar breakout game where the player attacks the center and the ball bounces around the perimeter. You can play it either on an oscilloscope or using an online emulator. [S-ol] wrote the game in Pure Data, a visual programming language for audio. The software controls the audio out channels and uses sound to control the game graphics. He also made use of the Zexy extension for Pure Data.

One of the cool things about this setup is that since the game is programmed with sound, all the sound effects also double as visual effects

We love oscilloscopes, and not just because they’re useful as hell. They also make sweet vector displays, like this analog pong game that uses a scope for a display. Even when they’re not being used for retrogaming they can be capable of some pretty amazing graphics.