Speak Your WiFi

When you create a Thing for the Internet of Things, you’ve made a little computer that does a simple job and which probably has a minimal interface. But minimal interfaces leave little room for configuration, such as entering WiFi details. Perhaps if you made the Thing yourself you’ve hard-coded your WiFi credentials in your code, but that hardly translates to multiple instances. So, how to put end-user WiFi credentials easily on more than one Thing? Perhaps [Rob Dobson] has the answer with his technique of sending them as a sequence of audible tones.

There is a piece of Javascript code in a browser into which you enter your WiFi credentials, which are then expressed through the speaker as a set of FSK tones to be picked up by a microphone on the Thing. They can then be decoded into the credentials, and the Thing can connect. All the code is available, on GitHub, should you fancy it yourself.

Of course, this is nothing new, as any owner of an 8-bit machine that had a cassette interface will tell you. And on the face of it it’s much easier than those awkward impromptu hotspots with a web interface to which you connect and pass on your credentials. But while we quite like the convenience, we can’t help wondering whether expressing the credentials in audible free space might be a bit too insecure for many readers. The technique however remains valid, and we’re sure that other less sensitive applications might be found for it. Meanwhile we hope he hasn’t inadvertently shared his WiFi password in the video below the break.

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The Swiss Army Knife of Audio Synthesis

Thirty years ago, we would be lucky if a computer could play audio. Take a computer from twenty years ago, and you’ll be lucky if it can play an MP3 in real-time. Now, computers can handle hundreds of tracks of CD-quality audio, and microcontrollers are several times more powerful than a desktop computer of the mid-90s. This means, of course, that microcontrollers can do audio very, very well. For his entry to the Hackaday Prize, [Fabien] is capitalizing on this power to create a Swiss Army knife of audio synthesis. It’s called the Noise Nugget, and it’s just what you need when you want to put audio in anything.

The microcontroller in question is an ARM Cortex-M4 running at 180MHz, with a quality DAC. There’s connectivity in the form of USB, two audio outs, one audio in, I2C, UART, and GPIOs. With this, you’ve got a digital synthesizer with a MIDI interface, audio effects for guitar pedal tomfoolery, an audio effect trigger board for playing pre-recorded sounds, a digital recorder, and a USB sound interface.

So, with all that processing power, what can the Noise Nugget actually do? Well, first of all, it’s a sampler. [Fabien] has a video demo of the Noise Nugget set up in sampler mode, where it can play a lute-ish sample and a cat sound. All of this is controlled over MIDI and played through a cheap speaker. The results — except for the cat sample — sound great. You can check that video out below.

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AV Synth is Psychedelic Analog Mayhem

Digital video is cool and all, but it can’t compete with analog in terms of smooth, creamy glitches and distortion. [gieskes] has developed an analog audio-visual synthesizer that is a great example of the old-school retro visuals you can create with a handful of simple components.

Known as the 3TrinsRGB+1c, it’s available both assembled and in kit form. It’s probably best to start with the manual. Synthesis is achieved through the use of a HEF40106 hex inverting buffer – a cheap and readily available part that nonetheless provides for excellent results. Video can be switched between RGB oscillators and a series of inputs, and there are various controls to create those classic scrolling effects and other visual oddities.

Additionally, a series of connections to the underlying circuitry are broken out on a header connector. This allows for extra modules to be plugged in, and several designs are available to expand the unit’s capabilities.

Analog video isn’t used so much on a day-to-day basis anymore, but it’s a great technology to tinker and experiment with. We’ve seen some of [gieskes] experiments in this arena before, too – like this Arduino video sampler. Video after the break.

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Faux Walkie-Talkie for Comedy Walking Tour is a Rapid Prototyping Win

Chances are good that a fair number of us have been roped into “one of those” projects before. You know the type: vague specs, limited budget, and of course they need it yesterday. But you know 3D-printers and Raspberduinos and whatnot; surely you can wizard something together quickly. Pretty please?

He might not have been quite that constrained, but when [Sean Hodgins] got tapped to help a friend out with an unusual project, rapid prototyping skills helped him create this GPS-enabled faux-walkie talkie audio player. It’s an unusual device with an unusual purpose: a comedic walking tour of Vancouver “haunted houses” where his friend’s funny ghost stories are prompted by location. The hardware to support this is based around [Sean]’s useful HCC module, an Arduino-compatible development board. With a GPS module for localization and a VS1053 codec, SD card reader, and a small power amp for the audio end, the device can recognize when the user is within 50 meters of a location and play the right audio clip. The housing is a 3D-printed replica of an old toy walkie-talkie, complete with non-functional rubber ducky antenna.

[Sean]’s build looks great and does the job, although we don’t get to hear any of the funny stuff in the video below; guess we’ll have to head up to BC for that. That it only took two weeks start to finish is impressive, but watch out – once they know you’re a wizard, they’ll keep coming back. Continue reading “Faux Walkie-Talkie for Comedy Walking Tour is a Rapid Prototyping Win”

One Man’s Quest to Build His Own Speakers

Why build your own stereo speakers? Some people like to work on cars in their garage. Some people build fast computers. Others seek the perfect audio setup. The problem for a newcomer is the signal to noise ratio among audiophile experts. Forums are generally filled with a vocal group of extremists obsessing on that last tiny improvement in some spec.  It can be hard for a beginner to jump in and learn the ropes.

[Ynze] had this problem. He’d finished a custom amplifier and decided to build his own speakers. He found a lot of spirited debates about what was important for good speakers. He tried to wade through the discussions and determine which things had real practical value. The results and his speaker build are documented in a post that you’ll want to check out if you would like to design and build your own speakers.

Some of the topics ranged from solder type to capacitor construction and 700 Euro capacitors. [Ynze’s] goal was to build something that sounded good while keeping costs in line. He claims he spent about 250 Euro and wound up with speakers equivalent to 750 Euro store-bought speakers.

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The Diaphragm is the Coil in These Flexible PCB Speakers

Speakers used to be largish electromechanical affairs, with magnets, moving coils, and paper cones all working together to move air around in a pleasing way. They’ve gotten much smaller, of course, small enough to screw directly into your ears or live inside the slimmest of smartphones and still delivery reasonable sound quality. The basic mechanism hasn’t changed much, but that doesn’t mean there aren’t other ways to make transduce electrical signals into acoustic waves.

Take these speakers made from flexible printed circuit boards, for instance. While working on his flexible PCB soft actuators, [Carl Bugeja] noticed that the PWM signals coursing through the coils on the thin PCB material while they were positioned over a magnet made an audible beeping. He decided to capitalize on that and try to make a decent speaker from the PCBs. An early prototype hooked to a simple amplifier showed promise, so he 3D-printed a ring to support the PCB like a diaphragm over a small neodymium magnet. The sound quality was decent, but the volume was low, so [Carl] experimented with a paper cone attached to the PCB to crank it up a bit. That didn’t help much, but common objects acting as resonators seemed to work fairly well. Check out the results in the video below.

This is very much a work in progress, but given [Carl]’s record with PCB creations from robotic fish to stepper motors built right into the PCB, we’d say he’ll make substantial improvements. Follow his and others’ progress in the Musical Instruments Challenge part of the 2018 Hackaday Prize.

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A Dozen Tubes Make An Educational Amplifier

If you asked [Hans_Daniel] what he learned by building a tube audio amplifier with a dozen tubes that he found, the answer might just be, “don’t wind your own transformers.” We were impressed, though, that he went from not knowing much about tubes to a good looking amplifier build. We also like the name — NASS II-12 which apparently stands for “not a single semiconductor.”

Even the chassis looked really good. We didn’t know textolite was still a thing, but apparently, the retro laminate is still around somewhere. It looks like a high-end audio component and with the tubes proudly on display on the top, it should be a lot of fun to use.

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