RF Modulation: Crash Course For Hackers

When you’re looking to add some wireless functionality to a project, there are no shortage of options. You really don’t need to know much of the technical details to make use of the more well-documented modules, especially if you just need to get something working quickly. On the other hand, …read more

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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 …read more

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Driving a 16×2 LCD with Voltage Modulation

The basic 16×2 LCD is an extremely popular component that we’ve seen used in more projects than we could possibly count. Part of that is because modern microcontrollers make it so easy to work with; if you’ve got an I2C variant of the display, it only takes four wires to …read more

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Musical Mod Lets MRI Scanner Soothe the Frazzled Patient

Hackers love to make music with things that aren’t normally considered musical instruments. We’ve all seen floppy drive orchestras, and the musical abilities of a Tesla coil can be ear-shatteringly impressive. Those are all just for fun, though. It would be nice if there were practical applications for making music from normally non-musical devices.

Thanks to a group of engineers at Case Western Reserve University in Cleveland, there is now: a magnetic resonance imaging machine that plays soothing music. And we don’t mean music piped into the MRI suite to distract patients from the notoriously noisy exam. The music is …read more

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ESP32 Makes for World’s Worst Radio Station

We can say one thing for [bitluni]: the BOMs for his projects, like this ESP32 AM radio transmitter, are always on the low side. That’s because he leverages software to do jobs traditionally accomplished with hardware, always with instructive results.

In this case, the job at hand is creating an RF oscillator in the broadcast AM band and modulating some audio onto it. From his previous experience using an ESP32 to watch video on an oscilloscope, [bitluni] knew that the microcontroller’s DACs were up to the task of producing an 800-kHz signal, and he managed to produce a more-or-less sine …read more

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Why is Donald Duck on the Radio? Math Behind Single Sideband Explained

AM, or amplitude modulation, was the earliest way of sending voice over radio waves. That makes sense because it is easy to modulate a signal and easy to demodulate it, as well. A carbon microphone is sufficient to crudely modulate an AM signal and diode — even a piece of natural crystal — will suffice to demodulate it. Outside of broadcast radio, most AM users migrated to single side band or SSB. On an AM receiver that sounds like Donald Duck, but with a little work, it will sound almost as good as AM, and in many cases better. If …read more

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Reverse Engineering the Nintendo Wavebird

Readers who were firmly on Team Nintendo in the early 2000’s or so can tell you that there was no accessory cooler for the Nintendo GameCube than the WaveBird. Previous attempts at wireless game controllers had generally either been sketchy third-party accessories or based around IR, and in both cases the end result was that the thing barely worked. The WaveBird on the other hand was not only an official product by Nintendo, but used 2.4 GHz to communicate with the system. Some concessions had to be made with the WaveBird; it lacked rumble, was a bit heavier than the …read more

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Mike Ossmann and Dominic Spill: IR, Pirates!

Mike Ossmann and Dominic Spill have been at the forefront of the recent wave of software-defined radio (SDR) hacking. Mike is the hardware guy, and his radio designs helped bring Bluetooth and ISM-band to the masses. Dominic is the software guy who makes sure that all this gear is actually usable. The HackRF SDR is still one of the best cheap choices if you need an SDR that can transmit and receive.

So what are these two doing on stage giving a talk about IR communication? Can you really turn traffic lights green by blinking lights? And can you spoof …read more

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MIDISWAY Promises to Step Up Your Live Show

If you like to read with gentle music playing, do yourself a favor and start the video while you’re reading about [Hugo Swift]’s MIDISWAY. The song is Promises, also by [SWIFT], which has piano phrases modulated during the actual playing, not in post-production.

The MIDISWAY is a stage-worthy looking box to sit atop your keys and pulse a happy little LED. The pulsing corresponds to the amount of pitch bending being sent to your instrument over a MIDI DIN connector. This modulation is generated by an Arduino and meant to recreate the effect of analog recording devices like an …read more

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Hybrid Technique Breaks Backscatter Distance Barrier

Low cost, long range, or low power — when it comes to wireless connectivity, historically you’ve only been able to pick two. But a group at the University of Washington appears to have made a breakthrough in backscatter communications that allows reliable data transfer over 2.8 kilometers using only microwatts, and for pennies apiece.

For those unfamiliar with backscatter, it’s a very cool technology that modulates data onto RF energy incident from some local source, like an FM broadcast station or nearby WiFi router. Since the backscatter device doesn’t need to power local oscillators or other hungry components, it has …read more

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