Arduino Traffic Light Sings The Song Of Its People

Getting an old traffic light and wiring it up to do its thing inside your house isn’t exactly a new trick; it’s so common that it wouldn’t normally pass muster for these hallowed pages. Even using one up to show the real-time status of your build or system resource utilization would be pushing it at this point. To get our attention, your traffic light is going to need to have a unique hook.

So how did [Ronald Diaz] manage to get his project to stand out from the rest? Interestingly enough, it’s nothing you can see. His traffic light doesn’t just look the part, it also sounds like the real thing. With far more effort and attention to detail than you’d probably expect, he’s made it so his Australian pedestrian traffic light correctly mimics the complex chirping of the original.

Working from a video of the traffic light on YouTube, [Ronald] was able to extract and isolate the tones he was after. Performing spectral analysis on the audio sample, he was able to figure out the frequency and durations of the eleven individual tones which make up the complete pattern. From the 973 Hz tone that only lasts 25 ms to the continuous 500 Hz “woodpecker”, every element of the sound was meticulously recreated in his Arduino code.

The Arduino Pro Mini used to control the traffic light is not only responsible for playing the tones through a piezo speaker, but as you might expect, for firing off the relays which ultimately control the red and green lamps. With everything carefully orchestrated, [Ronald] can now get that authentic Australian side-of-the-road experience without having to leave the comfort of his own home.

If you’d rather your in-home traffic light be more useful than realistic, we’ve got plenty of prior art for you to check out. This traffic light that tells you how the value of Bitcoin is trending is a great example. Or maybe this one that can tell you if the Internet is down.

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Synthesizing Mother Nature’s Sounds Like You’ve Never Seen Before

We’ve all heard the range of sounds to be made electronically from mostly discrete components, but what [Kelly Heaton] has achieved with her many experiments is a whole other world, the world of nature to be exact. Her seemingly chaotic circuits create a nighttime symphony of frogs, crickets, and katydids, and a pleasant stroll through her Hackaday.io logs makes how she does it crystal clear and is surely as delightful as taking a nocturnal stroll through her Virginia countryside.

Homemade piezo buzzer with amplifierThe visual and aural sensations of the video below will surely tempt you further, but in case it doesn’t, here’s a taste. When Radio Shack went out of business, she lost her source of very specific piezo buzzers and so had to reverse engineers theirs to build her own, right down to making her own amplifiers on circular circuit boards and vacuum forming and laser cutting the housings. For the sounds, she starts out with a simple astable multivibrator circuit, demonstrating how to create asymmetry by changing capacitors, and then combining two of the circuits to get something which sounds just like a cricket. She then shows how to add katydids which enhance the nighttime symphony with percussive sounds much like a snare drum or hi-hat. It’s all tied together with her Mother Nature Board built up from a white noise generator, Schmitt trigger, and shift registers to turn on and off the different sound circuits, providing a more unpredictable and realistic nighttime soundscape. The video below shows the combined result, though she admits she’ll never really be finished. And be sure to check out even more photos and videos of her amazing work in the gallery on her Hackaday.io page.

For the more familiar range of sounds, though no less varied, check out our own [Elliot William’s] series, Logic Noise, where he takes us through an extensive exploration of a less Mother Naturely soundscape.

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A Kitchen Timer Fit For MacGyver

Here’s a project that you don’t want to bring into an airport, ship through the mail, or probably even remove from your home. [ProjectGeek] has built himself a simple kitchen timer masquerading as a bomb. The build is actually pretty simple, but the end result is something that would look at home in a Hollywood action flick.

The timer circuit is built from four simple components. An 8051 microcontroller board is used as the primary controller and timer. The code is available on GitHub. This board is attached to a another board containing four momentary push buttons. These are used to program the timer and to stop the buzzing. Another board containing four 7-segment displays is used to show the remaining time on the timer. A simple piezo buzzer is used to actually alert you when the timer has run out. All of these components are connected with colorful jumper wires.

The physical part of this build is made from easily available components. Old newspapers are rolled up to form the “explosive” sticks. These are then covered in plain brown paper ordinarily used to cover text books. The rolls are bundled together and fixed with electrical tape. The electronics can then be attached to the base with some hot glue or double-sided tape.