Remoticon Video: Making Microphones And Finding Sound

December 8, 2020 by Mike Szczys 14 Comments

A yogurt lid and embroidery hoop are key components in building this microphone. It’s a super low tech, entry-level project to get into “found sound” and exactly what is needed to start hacking around in the audio world. This workshop presented by Helen Leigh and Robyn Hails shows you how to build a simple microphone and use it as the electronic gateway to all kinds of audio shenanigans.

Key to this build are the piezo element and an amp to process the signals it generates. All other materials are common around most households, but put them together as shown in this live hands-on seminar from the 2020 Hackaday Remoticon, and I think you’ll surprise yourself with how good the thing sounds!

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Exploring Custom Firmware On Xiaomi Thermometers

December 8, 2020 by Tom Nardi 55 Comments

If we’ve learned anything over the years, it’s that hackers love to know what the temperature is. Seriously. A stroll through the archives here at Hackaday uncovers an overwhelming number of bespoke gadgets for recording, displaying, and transmitting the current conditions. From outdoor weather stations to an ESP8266 with a DHT11 soldered on, there’s no shortage of prior art should you want to start collecting your own environmental data.

Now obviously we’re big fans of DIY it here, that’s sort of the point of the whole website. But there’s no denying that it can be hard to compete with the economies of scale, especially when dealing with imported goods. Even the most experienced hardware hacker would have trouble building something like the Xiaomi LYWSD03MMC. For as little as $4 USD each, you’ve got a slick energy efficient sensor with an integrated LCD that broadcasts the current temperature and humidity over Bluetooth Low Energy.

You could probably build your own…but why?

It’s pretty much the ideal platform for setting up a whole-house environmental monitoring system except for one detail: it’s designed to work as part of Xiaomi’s home automation system, and not necessarily the hacked-together setups that folks like us have going on at home. But that was before Aaron Christophel got on the case.

We first brought news of his ambitious project to create an open source firmware for these low-cost sensors last month, and unsurprisingly it generated quite a bit of interest. After all, folks taking existing pieces of hardware, making them better, and sharing how they did it with the world is a core tenet of this community.

Believing that such a well crafted projected deserved a second look, and frankly because I wanted to start monitoring the conditions in my own home on the cheap, I decided to order a pack of Xiaomi thermometers and dive in.

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How To Get Into Lost Wax Casting (with A Dash Of 3D Printing)

December 7, 2020 by Adam Zeloof 24 Comments

I’ve always thought that there are three things you can do with metal: cut it, bend it, and join it. Sure, I knew you could melt it, but that was always something that happened in big foundries- you design something and ship it off to be cast in some large angular building churning out smoke. After all, melting most metals is hard. Silver melts at 1,763 °F. Copper at 1,983 °F. Not only do you need to create an environment that can hit those temperatures, but you need to build it from materials that can withstand them.

Turns out, melting metal is not so bad. Surprisingly, I’ve found that the hardest part of the process for an engineer like myself at least, is creating the pattern to be replicated in metal. That part is pure art, but thankfully I learned that we can use technology to cheat a bit.

When I decided to take up casting earlier this year, I knew pretty much nothing about it. Before we dive into the details here, let’s go through a quick rundown to save you the first day I spent researching the process. At it’s core, here are the steps involved in lost wax, or investment, casting:

Make a pattern: a wax or plastic replica of the part you’d like to create in metal
Make a mold: pour plaster around the pattern, then burn out the wax to leave a hollow cavity
Pour the metal: melt some metal and pour it into the cavity

I had been kicking around the idea of trying this since last fall, but didn’t really know where to begin. There seemed to be a lot of equipment involved, and I’m no sculptor, so I knew that making patterns would be a challenge. I had heard that you could 3D-print wax patterns instead of carving them by hand, but the best machine for the job is an SLA printer which is prohibitively expensive, or so I thought. Continue reading “How To Get Into Lost Wax Casting (with A Dash Of 3D Printing)” →

Remoticon Video: How To Reverse Engineer A PCB

December 1, 2020 by Mike Szczys 4 Comments

You hold in your hand a circuit board from a product you didn’t make. How does the thing work? What a daunting question, but it’s both solvable and approachable if you know what you’re doing. The good news is that Eric Schlaepfer knows exactly what he’s doing and boiled down the process of reverse engineering printed circuit boards into this excellent workshop. It was presented live during the 2020 Hackaday Remoticon, and the edited video, which you’ll find below, was just published. Slides for the talk have been published on the workshop project page.

Need proof that he has skills that we all want? Last year Eric successfully reverse-engineered the legendary Sound Blaster audio card and produced his own fully-functional drop-in replacement called the Snark Barker. And then re-engineered it to work with the ancient MCA bus architecture. Whoa.

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Spider Silk, Spider Silk, Made Using A Strain Of Yeast

November 6, 2020 by Brian McEvoy 25 Comments

Companies spend thousands developing a project for the market, hoping their investment will return big. Investing like this happens every day and won’t shock anyone. What may surprise you is someone who spends more than a decade and thousands of their own dollars to make an open-source version of a highly-marketable product. In this case, we’re talking about genetically modified yeast that produces spider silk. If that sounds like a lead-in to some Spiderman jokes and sci-fi references, you are correct on both accounts. [Justin Atkin] had some geneticist work under his belt when he started, so he planned to follow familiar procedures like extracting black widow DNA, isolating and copying the silk genes, and pasting them into a yeast strain. Easy peasy, right? Naturally, good science doesn’t happen overnight.

There are a few contenders for the strongest spider silk among which the golden silk orb-weaver gets the most attention, but the black widow’s webbing is nearly as strong, and [Justin] is happy to wear black widow inspired bling, whereas the golden orb-weaver looks like it crawled out of Starship Troopers. His first attempt to extract DNA starts with a vial of preserved ~~nightmare fuel~~ spider specimens because that is a thing you can just go online and buy. Sadly, they were candied in alcohol, and that obliterates DNA, so he moved to dried specimens from breeders, which also failed to produce results, and those were just the landmark hangups.

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Local And Remote Debugging With GDB

November 6, 2020 by Maya Posch 27 Comments

As a debugger, GDB is a veritable Swiss Army knife. And just like exploring all of the non-obvious uses of a those knives, your initial response to the scope of GDB’s feature set is likely to be one of bewilderment, subsequent confusion, and occasional laughter. This is an understandable reaction in the case of the Swiss Army knife as one is unlikely to be in the midst of an army campaign or trapped in the wilderness. Similarly, it takes a tricky debugging session to really learn to appreciate GDB’s feature set.

If you have already used GDB to debug some code, it was likely wrapped in the comfort blanket of an IDE. This is of course one way to use GDB, but limits the available features to what the IDE exposes. Fortunately, the command line interface (CLI) of GDB has no such limitations. Learning the CLI GDB commands also has the advantage that one can perform that critical remote debug session even in the field via an SSH session over the 9600 baud satellite modem inside your Swiss Army knife, Cyber Edition.

Have I carried this analogy too far? Probably. But learning the full potential of GDB is well worth your time so today, let’s dive in to sharpen our digital toolsets.

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DIY Braille Embosser Is Really Impressive

October 10, 2020 by Kristina Panos 21 Comments

We weren’t surprised to learn that Braille tools are quite expensive. But it’s interesting to hear that there’s another class of tools altogether, and they are very cheap and imprecise. In devising the Braille Embossing Experience, aka BEE, [alatorre] sought to find an open-source middle ground. We think they succeeded marvelously.

Another surprising thing — while handheld embossers do exist, there is no system for filling out an A4 sheet of paper, say, to write a letter.

For Braille to be readable, the characters and lines must be properly spaced, and this requires some kind of moveable type-like device to correctly register the characters onto paper. BEE fills this void as well. The amazing thing is, there’s not much more to it than a marked-up piece of aluminum and some clever 3D printing.

There are two parts to this system — the positioning rail, which includes a landing box for the embosser with six holes in the bottom. The other part is a pair of embossers, one for letters A-M, and another for letters N-Z. To use BEE, just slide the rail to the right and start embossing letters right to left, then flip the paper over when finished.

Need to create something more permanent? Make a Braille PCB.