Hiding Data In Music Might Be The Key To Ditching Coffee Shop WiFi Passwords

In a move guaranteed to send audiophiles recoiling back into their sonically pristine caves, two doctoral students at ETH Zurich have come up with an interesting way to embed information into music. What sounds crazy about this is that they’re hiding data firmly in the audible spectrum from 9.8 kHz to 10 kHz. The question is, does it actually sound crazy? Not to our ears, playback remains surprisingly ok.

You can listen to a clip with and without the data on ETH’s site and see for yourself. As a brief example, here’s twelve seconds of the audio presenting two versions of the same clip. The first riff has no data, and the second riff has the encoded data.

You can probably convince yourself that there’s a difference, but it’s negligible. Even if we use a janky bandpass filter over the 8 kHz -10 kHz range to make the differences stand out, it’s not easy to differentiate what you’re hearing:

After many years of performing live music and dabbling in the recording studio, I’d describe the data-encoded clip as having a tinny feedback or a weird reverb effect. However, you wouldn’t notice this in a track playing on the grocery store’s speaker. Continue reading “Hiding Data In Music Might Be The Key To Ditching Coffee Shop WiFi Passwords”

Coffee Tables, Computers, And Railways

If you were a British kid at any time from the 1950s to the 1980s, the chances are that your toy shop had a train set in it. Not just any train set, but a full model railway layout in a glass case roughly the size of a pool table, with a button that when pressed started a timer and set a little tank engine off on a circuit with a pair of coaches. Magical for a generation raised on black-and-white TV, but probably not something that would cut it with today’s youth. A modern take on the glass-case layout comes from [Jack Flynn], who has created a coffee table with an automated and computerised N-gauge railway layout inside it. And this is definitely a railway rather than a railroad, the main locomotive is a Brush Type 4, a British Rail Class 47 diesel.

The modelling is a work of art, with a slightly idealised British street scene in an oval of double track against a backdrop of a rocky hillside. In the hill is an unexpected surprise which you can see on the video we’ve  placed below the break, and beneath it lie the electronics. A Teensy handles the track switching and all the various LED lights around the board, a Sprog DCC controller takes care of the trains, and overseeing everything is a Raspberry Pi running some custom software in Python with a web interface for control. We probably wouldn’t be able to resist a bit of remote-control railway action if our coffee table had a layout like this one!

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Protect Your Coffee Machine With A Filter Monitor

Coffee machines are delicate instruments, likely to be damaged by limescale. Thus they will often have a filter present, but filters have a limited capacity of water upon which they can be effective. At Make Bournemouth, they have approached the problem of when to change filters on their coffee machine by applying a bit of high-tech.

The water passing through the filter is monitored by a couple of DFRobot TDS modules, a flow meter, and a DS18B20 temperature sensor. The data from these is fed into an ESP32 dev board, which makes it available by a web interface for handy accessibility through a smartphone. It can then be used to work out how much of the filter’s capacity has been used, and indicate when a replacement is needed. All the code is available in a GitHub repository, and with luck now Bournemouth’s hackerspace will never see the coffee machine succumb to limescale.

Of course, this isn’t the first coffee maker water hack we’ve brought you. A year or two ago we told you about somebody making their pod coffee maker auto-fill too.

Hackaday Podcast Ep17: Are Cheap Microcontrollers Worth It? Android On Your Bike. Plus Food Printers And Coffee Bots

Join editors Mike Szczys and Elliot Williams as they recount a week of fascinating hacks. We take a good look at the PMS150C, a microcontroller that literally costs pennies but can only be flashed once. SNES emulators have a new trick up their sleeves to make low-def a lot less low, and you retro enthusiasts will either hate or love the NES zapper chandelier. Elliot’s enamored by a bike computer running Android core, and both Mike and Elliot delve into the food hacking scene, be it meat, chocolate, coffee, or of course frosting!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (72 MB of audio splendor)

Places to follow Hackaday podcasts:

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Make That Special Cup Of Coffee By Completely Tweaking The Coffee Machine

An interesting part of working on the Building Management and Control (BMaC) project – as previously covered on this site – was the reverse-engineering and ultimately the gaining of full control over the coffee machines at the office. Not the boring filter coffee machines, mind you, but the fully automatic espresso machine type that grinds beans, makes coffee, adds milk, and much more. Depending on one’s budget, naturally.

These little marvels of engineering contain meters of tubing, dozens of sensors, valves, ceramic grinders, and heating elements. The complexity of this machinery made us think that maybe there was more that we could do with these machines beyond what their existing programming and predefined products would allow. Naturally, there was.

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Schrödinger Quantum Percolator Makes Half Decent Coffee

I couldn’t decide between normal and decaffeinated coffee. So to eliminate delays in my morning routine, and decision fatigue,  I’ve designed the Schrödinger Quantum Percolator — making the state of my coffee formally undecidable until I drink it.

At its core, the Quantum Percolator contains a novel quantum event detector that uses electron tunneling to determine whether to use caffeinated or decaffeinated coffee. The mechanical components are enclosed in an opaque box, so I can’t tell which type of coffee is being used.

The result is coffee that simultaneously contains and does not contain caffeine – at least until you collapse the caffeination probability waveform by drinking it. As the expression goes, you can’t have your quantum superposition of states and drink it too!

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Mug-O-Matic Plots On Coffee Mugs

There is something fascinating about watching an autonomous machine. An automatic car wash, a soda vending machine that picks up the product behind a window, a plotter, or a robot like a CNC or 3D printer are all interesting to watch. Although [EngineerDog] bills Mug-O-Matic as a tiny CNC, we think it is more of a plotter for coffee mugs. It’s still fun to watch though, as you can see in the video below.

The design has about 60 printed parts and uses a Sharpie at the business end. It accepts gcode and can even emblazon your favorite mug with our own Jolly Wrencher, so you know we like it.

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