Zener Diode Tutorial

August 15, 2018 by Al Williams 22 Comments

We always enjoy [w2aew’s] videos, and his latest on zener diodes is no exception. In it, he asserts that all Zener diodes are not created equal. Why? You’ll have to watch the video below to find out.

Zener diodes are one of those strange items that have several uses but are not as popular as they once were. There was a time when the Zener was a reasonable way to regulate a voltage inexpensively and easily. Unfortunately the regulation characteristics were not very good, and the power lost was very high. But that was sometimes a reasonable trade, compared to putting a pass transistor and the associated discrete circuitry in place to make a linear regulator. With the advent of chips like the 7800-series regulators, you can have a high-quality regulator with one extra wire and still keep your costs under $1. Even if you want to do better and go with a switching power supply, that’s easy now and not much more expensive.

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Before Sending A Probe To The Sun, Make Sure It Can Take The Heat

August 15, 2018 by Roger Cheng 61 Comments

This past weekend, NASA’s Parker Solar Probe took off for a journey to study our local star. While its mission is well covered by science literate media sources, the equally interesting behind-the-scenes information is a little harder to come by. For that, we have Science News who gave us a look at some of the work that went into testing the probe.

NASA has built and tested space probes before, but none of them were destined to get as close to the sun as Parker will, creating new challenges for testing the probe. The lead engineer for the heat shield, Elizabeth Congdon, was quoted in the article: “Getting things hot on Earth is easier than you would think it is, getting things hot on Earth in vacuum is difficult.” The team used everything from a concentrated solar facility to hacking IMAX movie projector lenses.

The extreme heat also posed indirect problems elsewhere on the probe. A rocket launch is not a gentle affair, any cargo has to tolerate a great deal of shock and vibration. A typical solution for keeping fasteners in place is to glue them down with an epoxy, but they’d melt where Parker is going so something else had to be done. It’s not all high technology and exotic materials, though, as when the goal was to verify that the heat shield was strong enough to withstand up to 20G of acceleration expected during launch, the test team simulated extra weight by stacking paper on top of it.

All that testing should ensure Parker can perform its mission and tell us a lot of interesting things about our sun. And if you got in on the publicity campaign earlier this year, your name is along for the ride.

Not enough space probe action for the day? We’ve also recently featured how creative hacking gave the exoplanet hunter Kepler a second lease on life.

Every Shop Needs A Giant Wooden Utility Knife

August 15, 2018 by Tom Nardi 7 Comments

Generally speaking, we don’t cover that many woodworking projects here at Hackaday. What’s the point? It’s bad enough that wood reminds us of the outside world, but it hardly ever blinks, and forget about connecting it to Wi-Fi. This doesn’t seem to bother you fine readers, so we have to assume most of you feel the same way. But while we might not always “get” large woodworking projects around these parts, we’re quite familiar with the ~~obsession~~ dedication required to work on a project for no other reason than to say you managed to pull it off.

On that note, we present the latest creation of [Paul Jackman], a supersized replica of a Stanley utility knife made entirely out of wood. All wooden except for the blade anyway, which is cut from 1/8″ thick knife steel. That’s right, this gigantic utility knife is fully functional. Not that we would recommend opening too many boxes with it, as you’re likely to open up an artery if this monster slips.

We can’t imagine there are going to be many others duplicating this project, but regardless [Paul] has done a phenomenal job documenting every step of the build on his site. From cutting the rough shape out on his bandsaw to doing all painstaking detail work, everything is clearly photographed and described. After the break there’s even a complete build video.

The most interesting part has to be all of the little internal mechanisms, each one carefully reproduced at perfect scale from different woods depending on the requirements of the component. For example [Paul] mentions he choose white oak for the spring due to its flexibility. Even the screw to hold the knife closed was made out of a block of wood on the lathe.

For whatever reason, people seem to enjoy building scaled up replicas of things. We’ve seen everything from LEGO pieces to gold bars get the jumbo treatment. We suppose it’s easier than the alternative: building very tiny versions of big things.

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Don’t Forget Your Mints When Using This Synthesizer

August 15, 2018 by Bryan Cockfield 11 Comments

While synthesizers in the music world are incredibly common, they’re not all keyboard-based instruments as you might be imagining. Especially if you’re trying to get a specific feel or sound from a synthesizer in order to mimic a real instrument, there might be a better style synth that you can use. One of these types is the breath controller, a synthesizer specifically built to mimic the sound of wind instruments using the actual breath from a physical person. Available breath controllers can be pricey, though, so [Andrey] built his own.

To build the synthesizer, [Andrey] used a melodica hose and mouthpiece connected to a pressure sensor. He then built a condenser circuit on a custom Arduino shield and plugged it all into an Arduino Mega (although he notes that this is a bit of overkill). From there, the Arduino needed to be programmed to act as a MIDI device and to interact with the pressure sensor, and he was well on his way to a wind instrument synthesizer.

The beauty of synthesizers is not just in their ability to match the look and sound of existing instruments but to do things beyond the realm of traditional instruments as well, sometimes for a greatly reduced price point.

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Rover V2 Handles Stairs As Easily As The Outdoors

August 15, 2018 by Donald Papp 10 Comments

Rover V2 is an open-source, 3D-printable robotic rover platform that has seen a lot of evolution and development from its creator, [tlalexander]. There are a number of interesting things about Rover V2’s design, such as the way the wheel hubs themselves contain motors and custom planetary gearboxes. This system is compact and keeps weight down low to the ground, which helps keep a rover stable. The platform is all wheel drive, and moving parts like the suspension are kept high up, as far away from the ground as possible. Software is a custom Python stack running on a Raspberry Pi that provides basic control.

The Rover V2 is a full mechanical redesign of the previous version, which caught our attention with its intricate planetary gearing inside the wheel hubs. [tlalexander]’s goal is to create a robust, reliable rover platform for development that, thanks to its design, can be mostly 3D printed and requires a minimum of specialized hardware.

Track Everything, Everywhere With An IoT Barcode Scanner

August 15, 2018 by Sean Boyce 33 Comments

I’ve always considered barcodes to be one of those invisible innovations that profoundly changed the world. What we might recognize as modern barcodes were originally designed as a labor-saving device in the rail and retail industries, but were quickly adopted by factories for automation, hospitals to help prevent medication errors, and a wide variety of other industries to track the movements of goods.

Medication errors in hospitals are serious and scary: enter the humble barcode to save lives. Source: The State and Trends of Barcode, RFID, Biometric and Pharmacy Automation Technologies in US Hospitals

The technology is accessible, since all you really need is a printer to make barcodes. If you’re already printing packaging for a product, it only costs you ink, or perhaps a small sticker. Barcodes are so ubiquitous that we’ve ceased noticing them; as an experiment I took a moment to count all of them on my (cluttered) desk – I found 43 and probably didn’t find them all.

Despite that, I’ve only used them in exactly one project: a consultant and friend of mine asked me to build a reference database out of his fairly extensive library. I had a tablet with a camera in 2011, and used it to scan the ISBN barcodes to a list. That list was used to get the information needed to automatically enter the reference to a simple database, all I had to do was quickly verify that it was correct.

While this saved me a lot of time, I learned that using tablet or smartphone cameras to scan barcodes was actually very cumbersome when you have a lot of them to process. And so I looked into what it takes to hack together a robust barcode system without breaking the bank.

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Friday Hack Chat: LED Diffusion

August 15, 2018 by Brian Benchoff 27 Comments

A decade ago, the first Arduino projects featuring addressable RGB LEDs came on the scene, and the world hasn’t been the same since. Now we have full wall video displays with WS2812s and APA102s, wearable blinky, and entire suits of armor made of LEDs. The future is bright, and in RGB.

For this week’s Hack Chat, we’re going to be talking all about how to maintain the blinky without eye-searing brightness. It’s the LED Diffusion Hack Chat, full of tips and tricks on how to get the glowey without it being imprinted on your retina.

Our guest for this week’s Hack Chat is the incredible Becky Stern. Becky is one of the most prolific makers around and has a long history of fabricating some really, really cool stuff. She’s published hundreds of tutorials on everything from microcontrollers to computerized knitting machines, and has been featured by dozens of media outlets including the BBC, CNN, The Late Show with Colbert, VICE, and Forbes. Right now, she’s working at Autodesk with Instructables.

During this Hack Chat, we’re going to be talking all about diffusing LEDs, with topics including:

Taking some sandpaper to LEDs
Light pipes
3D printed LED enclosures
Looking into a bright blue LED with your remaining eye

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the Hack Chat Event Page and we’ll put that in the queue for the Hack Chat discussion.

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This week is just like any other, and we’ll be gathering ’round our video terminals at noon, Pacific, on Friday, August 17th. Need a countdown timer? Here ‘ya go.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.