Author: Zoe Skyforest

3645 Articles

Weird 555 Function Generator Uses Feedback

April 12, 2023 by 20 Comments

There are plenty of designs out there for sawtooth and triangle function generators, many of them using the humble 555 IC. Few are readily voltage controlled, making them difficult to work with using a DAC, though. Enter this useful design posted to EDN!

The nifty design allows both waveshape and amplitude to be controlled via voltage. You could hook up a couple of  potentiometers and call it done. Or, even better, you can control these parameters via PWM output from a microcontroller. Handy, no? It’s achieved by a fancy routing that sends feedback from the 555’s output pin to the CV input, instead of the usual design that uses the THR and TRG pins instead. The design also allows the production of both symmetrical and asymmetrical triangle waveforms, and as a bonus, the whole oscillator draws less than 4 mW of power.

If you’re looking for a nifty triangle/sawtooth generator that sits neatly in your otherwise-digital design, this could be for you. Or, you might like to explore the sheer mountain of other 555 hacks we’ve featured over the years. We even held a contest! If you’ve got new 555 hacks the world needs to see, don’t hesitate to drop them into the tipsline.

 

If They Fire The Nukes, Will They Even Work?

April 6, 2023 by 146 Comments

2022 was a harrowing year in a long line of harrowing years. A brutal war in Europe raised the prospect of nuclear war as the leaders behind the invasion rattled sabers and made thinly veiled threats to use weapons of mass destruction. And all this as we’re still working our way through the fallout of a global pandemic.

Those hot-headed threats raise an interesting question, however. Decades have passed since either Russia or the United States ran a live nuclear weapons test. Given that, would the nukes even work if they were fired in anger?

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How Tattoos Interact With The Immune System Could Have Impacts For Vaccines

April 5, 2023 by 40 Comments

Tattoos are an interesting technology. They’re a way of marking patterns and designs on the skin that can last for years or decades. All this, despite the fact that our skin sloughs off on a regular basis!

As it turns out, tattoos actually have a deep and complex interaction with our immune system, which hold some of the secrets regarding their longevity. New research has unveiled more insight into how the body responds when we get inked up.

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The Liquid Trees Of Belgrade: The Facts Behind The Furore

April 4, 2023 by 126 Comments

Historically, nature has used trees to turn carbon dioxide back into oxygen for use by living creatures. The trees play a vital role in the carbon cycle, and have done so for millennia. Recently, humans have thrown things off a bit by getting rid of lots of trees and digging up a lot more carbon.

While great efforts are underway to replenish the world’s tree stocks, Belgrade has gone in a different direction, creating artificial “liquid trees” to capture carbon dioxide instead. This has spawned wild cries of dystopia and that the devices are an affront to nature. Let’s sidestep the hysteria and look at what’s actually going on.

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Largest Ever Hydrogen Fuel Cell Plane Takes Flight

April 3, 2023 by 72 Comments

In the automotive world, batteries are quickly becoming the energy source of the future. For heavier-duty tasks, though, they simply don’t cut the mustard. Their energy density, being a small fraction of that of liquid fuels, just can’t get the job done. In areas like these, hydrogen holds some promise as a cleaner fuel of the future.

Universal Hydrogen hopes that hydrogen will do for aviation what batteries can’t. The company has been developing flight-ready fuel cells for this exact purpose, and has begun test flights towards that very goal.

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Tennis Balls Serve As Decent Bicycle Tires That Don’t Easily Puncture

April 3, 2023 by 41 Comments

Pneumatic tires provide a great ride, great grip, and yet have one fatal flaw — they’re always getting punctured and leaving you stranded. [The Q] decided to solve this problem with a unique design: tires that use tennis balls as the cushioning medium instead.

The build begins with small cut sections of plastic water pipe. These are used as housings to hold tennis balls, which are pressed in with a unique tool of [The Q]’s own construction. The individual ball assemblies are then bolted into a standard bicycle wheel, and a tread from a regular bike tire is stretched around the outside for grip.

It goes without saying that these tires won’t offer the same quality of ride as regular pneumatic bike tires. Nor will the performance be as good, due to the significant extra unsprung weight. They are eye-catching and fun, however. Plus, if you live in an area with tons of nails or prickles, you might find these are just the ticket. Maybe.

We’ve seen some other great bike hacks before, too.

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Sound Sculpture Uses Daisy Seed To Generate Audio

April 2, 2023 by No comments

Here at Hackaday, we love a good art piece, whether that involves light or sound. Combining both is a sure-fire way to get our attention, and [Eirik Brandal] did just that with his Void Extrusion piece.

The project is built around the Daisy Seed from Electrosmith. It’s an embedded platform designed for musical purposes, which made it perfect for [Eirik]’s project. Based on an STM32 chip, it’s very capable when it comes to DSP tasks. In this role, it’s charged with algorithmic music composition, providing the captivating soundtrack that emanates from the sculpture.

The sculpture itself looks almost like a fancy mid-century home from the Hollywood Hills, but it’s fundamentally a little more abstract than that. [Eirik] built it as an opportunity to experiment with using 3D printed forms in his work. To that end, it features a beautiful diffused LED wall and a speaker enclosure as an integral part of the build. The LEDs are run from an Arduino Nano Every.

[Eirik’s] work shows us that “generative” music can be intoxicating and compelling with a real sense of feeling and mood. The sculpture is a visually-capable pairing that works with the soundscape. It recalls us of some other great artworks we’ve featured from [Eirik] before, too.

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