Year: 2020

An Open Source Tool To Document Your Wiring

June 23, 2020 by 29 Comments

Most of us are familiar with the tools available to create circuit diagrams, as generally that’s the first step towards producing a custom PCB. But that about the cables and wiring harnesses that don’t live on your board? How do you easily document the rat’s nest perfectly logical wiring of your latest and greatest creation?

That’s precisely the question that led [Daniel Rojas] to create WireViz. This open source Python tool takes human readable input files and turns them into attractive and functional visualizations of where all the wires in your project are going. It can even be used to generate a Bill of Materials that documents the lengths of wire required and types of connectors needed to hook everything up.

If you’re still using pre-made cables to connect all of your components together, than you might not immediately see the benefit of a tool like this. But as we’ve talked about in the past, the creation of custom wiring harnesses is something that serious hardware hackers should become familiar with. Yes it takes more effort, but the end result is worth it. With a tool like WireViz, the creation of a bespoke harness for your next project just got a little bit easier.

[Daniel] has done a fantastic job documenting this project, providing not only a tutorial on how to feed and care for your WireViz, but a gallery of examples that shows off the kind of complex wiring the tool can help make sense of. But there’s plenty more to be done, and he’s happy to get feedback or code contributions from anyone who wants to get involved.

Eico Signal Generator Gets A Repair

June 23, 2020 by 5 Comments

The Eico model 377 was a pretty common audio signal generator. [The Radio Mechanic] picked one up from 1956 that was in reasonably good shape, and shares a teardown and repair of the unit that you can see in the video below. The device could produce sine and square waves using a few tubes.

The unit was a bit different inside than expected because there were several versions made that shared the same model number. The bottom of the case had some goo in it, which is never a good sign. Unsurprisingly, the culprit was an old capacitor.

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Macros For A Mazda

June 23, 2020 by 16 Comments

[Arik Yavilevich] recently upgraded his second-gen Mazda’s control console, going from the stock busy box to an Android head unit that does it all on a nice big touchscreen. It can also take input from the handy steering wheel buttons — these are a great option for keeping your eyes on the road and occasionally startling your unsuspecting passengers when the radio station suddenly changes.

The only problem is that [Arik]’s stock steering wheel doesn’t have any media-specific buttons on it. After a short trip to the junkyard, [Arik] had a fancier wheel to go along with the new head unit.

[Arik] doesn’t use cruise control, and those particular buttons can’t be hooked up with reprogramming the car’s computer, so he made them into macro buttons that control the head unit over Bluetooth, using an STM32 black pill board stashed in the glove box.

[Arik] found out that the cruise control buttons don’t ride the CAN bus — they use a resistor ladder/voltage divider and go directly into the ECU. After that it was mostly a matter of finding the right wires and then cutting and re-routing them to make the buttons work on the ACC setting as well as ON. A brief demo video is idling after the break.

Have an old smart phone lying around? Of course you do. Why not make your own head unit?

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Building A Scooter Exhaust From Scrap Metal

June 23, 2020 by 20 Comments

When a part on a vehicle fails, oftentimes the response is to fit a new one fresh out the box. However, sometimes, whether by necessity or simply for the love of it, it’s possible to handcraft a solution instead. [Samodel] does just that when whipping up a new exhaust for his scooter out of scrap metal.

It’s a great example of classic backyard metalworking techniques. The flange is recreated using a cardboard template rubbed on the exhaust port, with the residual oil leaving a clear impression. Hard work with a grinder and drill get things started, with an insane amount of filing to finish the piece off nicely. A properly tuned pipe is then sketched out on the computer, and a paper template created. These templates are cut out of an old fridge to create the main muffler section.

There’s plenty of other hacks, too – from quick and dirty pipe bends to handy sheet forming techniques. It’s not the first time we’ve seen great metalworking with scrap material, either. Video after the break.

[Thanks to BrendaEM for the tip]

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Ask Hackaday: Is Our Power Grid Smart Enough To Know When There’s No Power?

June 23, 2020 by 63 Comments

Just to intensify the feeling of impending zombie apocalypse of the COVID-19 lockdown in the British countryside where I live, we had a power cut. It’s not an uncommon occurrence here at the end of a long rural power distribution network, and being prepared for a power outage is something I wrote about a few years ago. But this one was a bit larger than normal and took out much more than just our village. I feel very sorry for whichever farmer in another village managed to collide with an 11kV distribution pole.

What pops to mind for today’s article is the topic of outage monitoring. When plunged into darkness we all wonder if the power company knows about it. The most common reaction must be: “of course the power company knows the power is out, they’re the ones making it!”. But this can’t be the case as for decades, public service announcements have urge us to report power cuts right away.

In our very modern age, will the grid become smart enough to know when, and perhaps more importantly where, there are power cuts? Let’s check some background before throwing the question to you in the comments below.

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Chaotic Oscillator From Antique Logic

June 23, 2020 by 35 Comments

While working on recreating an “ancient” (read: 60-year-old) logic circuit type known as resistor-transistor logic, [Tim] stumbled across a circuit with an unexpected oscillation. The oscillation appeared to be random and had a wide range of frequency values. Not one to miss out on a serendipitous moment, he realized that the circuit he built could be used as a chaotic oscillator.

Chaotic systems can be used for, among other things, random number generation, so making sure that they do not repeat in a reliable way is a valuable property of a circuit. [Tim]’s design uses LEDs in series with the base of each of three transistors, with the output of each transistor feeding into the input of the next transistor in line, forming a ring. At certain voltages close to the switching voltages of the transistors, the behavior of the circuit changes unpredictably both in magnitude and frequency.

Building real-life systems that exhibit true randomness or chaotic behavior are surprisingly rare, and even things which seem random are often not random enough for certain applications. [Tim]’s design benefits from being relatively simple and inexpensive for how chaotic it behaves, and if you want to see his detailed analysis of the circuit be sure to visit his project’s page.

If you want to get your chaos the old fashioned way, with a Chua circuit, look out for counterfeit multipliers.

USB-C Is Taking Over… When, Exactly?

June 23, 2020 by 179 Comments

USB is one of the most beloved computer interfaces of all time. Developed in the mid-1990s, it undertook a slow but steady march to the top. Offering an interface with good speeds and a compact connector, it became the standard for hooking up interface devices, storage, and even became the de-facto way to talk old-school serial, too.

In late 2014, the USB Implementers Forum finalised the standard for the USB-C plug. Its first major application was on smartphones like the Nexus 5X, and it has come to dominate the smartphone market, at least if you leave aside the iPhone. However, it’s yet to truly send USB-A packing, especially on the desktop. What gives? Continue reading “USB-C Is Taking Over… When, Exactly?” →