Hackaday Links: November 22, 2015

There’s a new documentary series on Al Jazeera called Rebel Geeks that looks at the people who make the stuff everyone uses. The latest 25-minute part of the series is with [Massimo], chief of the arduino.cc camp. Upcoming episodes include Twitter co-creator [Evan Henshaw-Plath] and people in the Madrid government who are trying to build a direct democracy for the city on the Internet.

Despite being a WiFi device, the ESP8266 is surprisingly great at being an Internet of Thing. The only problem is the range. No worries; you can use the ESP as a WiFi repeater that will get you about 0.5km further for each additional repeater node. Power is of course required, but you can stuff everything inside a cell phone charger.

I’ve said it before and I’ll say it again: the most common use for the Raspberry Pi is a vintage console emulator. Now there’s a Kickstarter for a dedicated tabletop Raspi emulation case that actually looks good.

Pogo pins are the go-to solution for putting firmware on hundreds of boards. These tiny spring-loaded pins give you a programming rig that’s easy to attach and detach without any soldering whatsoever. [Tom] needed to program a few dozen boards in a short amount of time, didn’t have any pogo pins, and didn’t want to solder a header to each board. The solution? Pull the pins out of a female header. It works in a pinch, but you probably want a better solution for a more permanent setup.

Half of building a PCB is getting parts and pinouts right. [Josef] is working on a tool to at least semi-automate the importing of pinout tables from datasheets into KiCad. This is a very, very hard problem, and if it’s half right half the time, that’s a tremendous accomplishment.

Last summer, [Voja] wrote something for the blog on building enclosures from FR4. Over on Hackaday.io he’s working on a project, and it’s time for that project to get an enclosure. The results are amazing and leave us wondering why we don’t see this technique more often.

Hacklet 85: Alternative Audio Amplifiers

When you think of amplifiers, you’re probably thinking of audio or some big ‘ol power amps for radios. While interesting, there are some very interesting ‘alternative’ amplifiers floating around hackaday.io that are more than just power amps, and exceedingly useful, to boot.

1601181393316190625[Ronald] bought an XMS amplifier a few years ago, and although it worked well, every time he changed the input, the loudness had to be toggled. One thing led to another, and he realized this amplifier had a four-channel audio processor that could be controlled by I2C. This was the beginning of his Network Amplifier.

Inside the box is a Raspberry Pi that controls a PT2314-based amplifier. Also included is a 2×16 character LCD, a few LEDs, switches, and a rotary encoder.  There was an Android app that controlled the amplifier, but this was discarded for a better looking web-based solution. Now [Ronald] has every audio source available over WiFi.

973501443636885535What if you want an audio amplifier without a speaker? Wait, what? That’s what [DeepSOIC] is doing with his experiments in ion wind loudspeakers.

‘Ion wind lifters’ have been around for decades now, mostly in the labs of slightly off-kilter people who believe this is the technology aliens are using to visit earth. Nevertheless, ion wind lifters produce an airflow, and if you make that wind variable, you get sound. Pretty cool, huh?

The amplifier for this project uses a tube to modulate kilovolt supply through the ion ‘blower’. Does it work? Sure does. [DeepSOIC] got a piece of 0.2 mm nichrome wire to discharge ions into the air, after which the ions drift into the second electrode. The result is sound, and the entire project is built deadbug style. It really doesn’t get cooler than this.


2981611414932529525Continuing with the tube amp trend, [Marcel] built the cheapest little tube amp around.

The design of an audio tube amp is fairly simple business. First, you start with a big ‘ol transformer, and rectify the AC into DC. This gets fed into a preamp tube, and this is fed into a bigger power tube.

In about 50 years of development, tube designers had the technology down pat by the mid 1950s, and triode/pentode tubes were created. This allowed tube designers to condense two amplifier stages into a single tube. While this setup was usually used for cheap, toy-like electronics, you can still buy the ECL82 tube today.

[Marcel] took one of these tubes, added a rectifier tube, transformer, and big cap to create the simplest possible tube amp. Use it for guitars, use it for hi-fis, it’s all the same. It’s not going to sound great, but it is a very easy amp to build.

All of these interesting audio amplifier projects are curated on this new list! If you have a build that amplifies sound in an interesting way, don’t be shy, just drop [Adam] a message on Hackaday.io and he’ll add it. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

The Best Conference Badge Hacking You’ve Ever Seen

72EJpM5noCVCOQOeMV74_fmZeSQKcPxiqv70JYc9psgAs with any proper hardware con, the Hackaday Supercon needed a badge, and preferably one that was electronic. This conference centered around hardware creation, and the badge was no exception.

Designed on a tight timeline, it was possible to deliver a PCB badge for the attendees but it didn’t include microcontrollers, FPGAs, or software defined radios. This blank slate was the foundation for a completely unconstrained freestyle electronics soldering session.

The front of the badge includes a matte black solder mask with Truchet tiles of traces. Put multiple badges edge-to-edge and the pattern continues indefinitely. Inside of each curved trace is a through-hole via and those makes up a grid of holes on the back of the badge. On that back side there are also two rectangular grids that presented a nice area to which hackers soldered their components.

More than a few people took up the challenge of hacking their badge, and despite a strange pitch for the through holes (0.230″), and traces that didn’t go anywhere, there were some amazing builds. I would go so far to say that the badge hacking at the Supercon was the best I’ve ever seen, and this includes DEFCON and CCC.

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Code Craft-Embedding C++: Hidden Activities?

What is an embedded system? The general definition is a computer system dedicated to a specific purpose, i.e. not a general purpose system usable for different tasks. That is a very broad definition. I was just skimming the C++ coding guidelines for the Joint Strike Fighter. That’s a pretty big embedded system and the first DOD project that allowed C++! When you use an ATM to get money you’re using an embedded system. Those are basically hardened PCs. Then at the small end we have all the Internet of Things (IoT) gadgets.

The previous articles about embedding C++ discussing classes, virtual functions, and macros garnered many comments. I find both the positive and critical comments rewarding. More importantly, the critical comments point me toward issues or questions that need to be addressed, which is what got me onto the topic for this article. So thank you, all.

Let’s take a look at when embedded systems should or should not use C++, taking a hard look at the claim that there may be hidden activities ripe to upset your carefully planned code execution.

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Review: Voltera V-One PCB Printer

Back in Feburary, I was one of the first people to throw some cash at the Voltera V-One circuit board printer on Kickstarter. With an anticipated delivery date of Q4 2015, I sat back and waited. This week, my V-One arrived!

I’ll preface this article by pointing out that I do know the folks at Voltera as we went to university together. That being said, I did put down my own cash for the device, so I’ve bought the right to be critical. I also have no relationship with their company. In this article, we’ll go through unboxing and printing, then get into a review of the V-One based on what we’ve seen so far.

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ON Semiconductor Acquires Fairchild

In the continuing process of semiconductor companies buying each other up, ON Semiconductor has acquired Fairchild Semiconductor for $2.4 Billion.

ON Semi and Fairchild’s deal is only the latest in a long line of mergers and acquisitions. We’ve recently seen Dialog’s buyout of Atmel, Avago’s purchase of Broadcom,  NXP and Freescale’s merger, and soon might see TI buy Maxim. We’re currently in the great time of acquisition, with nearly $100 Billion flowing from company to company in just a few months.

Companies have cash to spend and costs to cut. This latest deal is expected to save $150 Million in annual costs.

Fairchild has a long and storied history in the semiconductor industry, with the first integrated circuit produced in a Fairchild lab in Palo Alto. [Bob Widlar] made Fairchild his home until famously leaving for National Semiconductor in 1965. Somewhat ironically, Fairchild Semiconductor was bought by National Semiconductor in 1987.

ON Semiconductor’s history is not nearly as interesting, being spun off of Motorola’s semiconductor business in 1999. Although ON’s main line of business was discrete components, ON also has a catalog of quite a few power management ICs.

Unfortunately, because ON Semi bought Fairchild and not the other way around, we’re stuck with what is probably the worst logo in the entire semiconductor industry: drop-shadowed balls are so mid-90s!

Simple Devices Protecting Our Water System

We are all used to turning on the faucet and having clean, drinkable water on demand. But think about what happens afterwards in your home: that water is used to wash dishes or water lawns and many other uses that render it undrinkable. What stops this nasty water from flowing back into your pipes and out of your kitchen faucet? A backflow preventer. This simple, but vital, part of your plumbing turns your water pipes into one-way systems that give out clean, drinkable water. This isn’t just about making your water taste nice: backflow preventers protect your water supply from things like brain-eating amoeba and E Coli that could kill.

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