Month: November 2016

Swear Bleep Detecting Eyebrows

November 10, 2016 by 17 Comments

Swear on broadcast television and they’re going to bleep out the audio to protect the sensibilities of the general public. Swear bleeps are fairly standardised at 1kHz, or so [mechatronicsguy] tells us. You learn something new every day.

OK, it’s not as though there’s an ISO document somewhere detailing the exact tone to use when someone says a naughty word on camera, it is far more likely that a 1kHz tone is the most likely frequency to be at hand in a studio. It’s so ubiquitous that even audio engineers with nowhere near perfect pitch can identify it, and one to which an acquaintance of ours swears years of exposure have given his ears a selective notch filter.

Armed with this information, [mechatronicsguy] created a fun project. As a fan of the [electroBOOM] Youtube channel he made a set of LED eyebrows for a picture of his bleep-prone hero, and using a Teensy with its audio and FFT libraries he made them light up whenever a 1kHz tone is detected. It’s not the most amazing of hacks, but if you find yourself in need of a smile on a chilly November morning then maybe it’ll have the same effect on you as it did with us. He’s posted a quick video of the ‘brows in action which we’ve embedded below the break.

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Acids, Bases And The Power Of Hydrogen

November 10, 2016 by 19 Comments

The 1970’s was the decade that illuminated the threat of acid rain to the citizens of the US. It had been known to exist several years before, but the sources of the problem did their best to suppress the information. It wasn’t until the environmental damage became significant enough to draw national attention that it would lead to the US enacting regulations to stop acid rain.

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Source

Truthfully, most of the public was probably still unaware of what acid rain actually was. The default mental image that comes to the mind of the non-chemist is large drops of battery acid raining down from the heavens and devouring everything. This is not quite the case, however. Pure water has a neutral pH of 7. Normal rain is actually slightly acidic as it picks up CO2 from the air, making carbonic acid. But when this “normal” rain mixes with the byproducts of industrial plants that pump out large amounts of  SO2 (sulfuric dioxide) and NO (nitrogen oxide) into the atmosphere, it becomes even more acidic – down to a pH of 3. This “acid” rain has the acidity of citrus juice, so it’s not going to set the world on fire. But it will wreak havoc on local ecosystems.

The 1990’s brought with it tough government regulations on the output of SO2 and NO by large factories, pretty much eliminating acid rain in the US. The rise and fall of acid rain is a great example of why we should educate ourselves on the basic chemistries that define our lives, even though we might not be actual chemists. In this article, we’re going back to your first year of college and hash out just what defines an acid and base. And solidify our understanding of the pH scale. It is essential for the future biohacker to have this knowledge in their toolbox.

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Really Big Digital Clock Finds Use For Really Big 3D Printer

November 10, 2016 by 22 Comments

What does it take to make a really big digital clock? If [Ivan Miranda]’s creation is any gauge, it takes a really big 3D printer, an armful of Neopixel strips, and a ton of hot melt glue.

It looks like [Ivan]’s plus-size clock is mainly an exercise for his recently completed large-bed custom 3D printer, in itself a project worth checking out. But it’s a pretty ambitious project, and one that has some possibilities for enhancements. Each of the four seven-segment displays was printed separately, with a black background, translucent white for the segments, and recesses for five RGB LEDs each. The four digits and colon spacer are mated together into one display, and an ESP8266 fetches the time from a NIST server and drives the segments. What’s really interesting about [Ivan]’s projects is that he constrains himself to finishing them each in a week. That explains the copious amount of hot glue he uses, and leaves room for improvements. We’d love to see this display built into a nice walnut case with a giant red diffusing lens. Even as it stands it certainly makes a statement.

We’ve featured other outsized seven-segment displays before, but few as big as this one.

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1MHz, 2 Boards, 4 Bits And A Homebrew CPU

November 10, 2016 by 17 Comments

[Agp.cooper] saw a vintage 4Kx4 bit RAM chip and decided that it needed a CPU design to match. The TTL design fits on two boards and has a functional front panel.

This custom CPU project has a few interesting bits worth noting. First, it is small enough that you can wrap your head around it pretty easily. And [Agp.cooper] gives  a good account of the instructions set architecture choices he considered and why he settled on the final design.

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Sunrise Alarm Clock With Organic Twist

November 9, 2016 by 10 Comments

Most hardware hackers have a clock project or two under their belt. A pretty common modification to a generic clock is to add lights to it, and if the clock has an alarm feature, it’s not too big of a stretch to try to get those lights to simulate a sunrise for a natural, peaceful morning alarm. The problem that a lot of us run across, though, is wiring up enough LEDs with enough diffusion to make the effect work properly and actually get us out of bed without an annoying buzzer.

Luckily for all of us, [jarek319] came up with an elegant and simple solution that should revolutionize all future sunrise alarm clock builds. He found a cheap OLED display and drove it with an LM317 voltage regulator. By driving the ADJ pin on the regulator, he was able to effectively drive the OLED with a makeshift PWM signal. This allows the OLED’s brightness to be controlled. [jarek319] threw some NTP code up on an ESP12E and did a little bit of programming for the alarm, and the problem is solved.

While an OLED is pretty much the perfect solution for a sunrise alarm clock, if you have a problem sourcing one or are just looking for an excuse to use up a strip of addressable LEDs, you can build a sunrise alarm clock out of almost any other light source.

Print Directly On Fabric With An Inkjet Printer

November 9, 2016 by 8 Comments

[fungus amungus] was reading online about printing directly on fabrics with a home printer. He’d read a few hopeful tutorials about printing on them with a laser printer, but he didn’t own one.

Considering that you can occasionally buy an inkjet for less than the ink, he decided to take the plunge and see if he could print on a swatch of fabric with his inkjet. The technique requires a printer, some wax paper, scissors, and an iron.

By adhering the wax paper to the fabric properly, it’s possible to run it through the printer without tears. (We’ll let you pick the heteronym.) The final step is to let the ink sit for an hour before running the iron over it again. This seems to cure the ink and it can even survive a few washings.

Being able to make any pattern of cloth on demand seems like a useful thing to keep in the toolbox!

Stormtrooper Voice Changer Helmet Uses Teensy To Mangle Audio

November 9, 2016 by 27 Comments

Halloween has come and gone, but this DIY voice changing Star Wars Stormtrooper helmet tutorial by [Shawn Hymel] is worth a look for a number of reasons. Not only is the whole thing completely self-contained, but the voice changing is done in software thanks to the Teensy’s powerful audio filtering abilities. In addition, the Teensy also takes care of adding the iconic Stormtrooper clicks, pops, and static bursts around the voice-altered speech. Check out the video below to hear it in action.

Besides a microphone and speakers, there’s a Teensy 3.2, a low-cost add-on board for the Teensy that includes a small audio amp, a power supply… and that’s about it. There isn’t a separate WAV board or hacked MP3 player in sight.

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