Here's a gem from hackaday that caught our eye. In the spirit of their Retrotechtacular series -- featuring David Richards' steam powered (and period-accurate) machine shop!

....It represents approximately what a 1920’s machine shop would look like in America. Not a single tool is newer than 1925. The whole shop is powered by a line shaft using steam power. A massive boiler provides steam for a Pennsylvania built 5 by 5 steam engine, dating back to approximately 1895. Using belts and clutches, it powers a few lathes, drill presses, a mill, and even a shaper — an identical machine to one in the Edison Museum!
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Forbes speaks with Jamie Hyneman from Mythbusters and Dale Dougherty from Make Magazine about the rise of the Maker Movement over the past 15 years and its impacts on business and mainstream culture in this interview with Dale Dougherty. This section discussing crowdfunding was of particular interest to us:

...Rather unsurprisingly, the rise of the makers has had a tremendous impact on innovation. While the Internet got people interested in building software and web applications, for many years the passion for building physical things lagged behind. The makers changed all of that.

This has resulted in a remarkable age where inventors and innovators have the perfect combination of computing (e.g. Raspberry Pi/Arduino and their sensors), software (Linux/Open Source/SDKs), manufacturing (3-D Printing/CNC), and data (e.g. Amazon Web Services/Big Data). What was still missing was the ability to get maker creations into the hands of others.

That changed with Kickstarter.

...Dougherty believes that this crowdfunding model has played a critical role in the growth of the maker movement.

“It’s really important. Last year, Kickstarter told us that 10% of the makers at Maker Faire had run a campaign, and collectively they had raised $23 million,” he says. “I was at Maker Faire Shenzhen last month and every Chinese maker who had a product had run a Kickstarter.”

“This means that makers have access to small amounts of capital to start product development,” Dougherty says. “But perhaps the most important thing that crowdfunding does is help to develop a community for a product — even before the product exists.” ....

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Sigzig shared the details of an experiment to calculate current by measuring input impedance. via dangerous prototype:

Input impedance on measurement equipment is usually kept as high as it can in an effort to prevent loading down the signals the equipment is measuring. For example most general purpose digital multimeters aim for an input impedance of at least 1M ohm. The Zig-4 has a lower input impedance of 330k ohms but this is still high enough for many/most situations. That being said it is still important to understand input impedance and its affect on your measurements.

In this post I thought it would be fun to actually take advantage of the 330k input impedance of the Zig-4 as a sort of low current sensing.

The goal: To see if we can use the Zig-4 to detect a change in current in the very low nA range.

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Jay Doscher does a thorough job of sharing details of his experiment to produce a RasPi 2 outdoor unit -- which he amusingly calls an "RPFU" -- including lessons learned from this round:

I've been working hard on a project that allows me to take a Raspberry Pi 2 into the wild outdoors.  While there are many cases out there that work fine in a cabinet or on a desk, I couldn't find one that would work outdoors.  I became familiar with weatherproof enclosures when I started tinkering with my Solarbot a couple years ago, but I needed more than a small plastic box this time.  This time around I wanted something that would support my Solar Robot 7 (which is live on Twitter here), a Raspberry Pi 2- powered solar tracker.  More on that soon! ....
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hackaday pointed out an interesting experiment at the heart of Dan Berard's latest project updates:

...In his search for a better actuator [Dan] thought he’d try using MLCC capacitors! While not known for their electromechanical properties, you may have encountered capacitors that appear to “sing” (PDF), emitting an audible tone. This is due to the piezoelectric properties of BaTiO3. Effectively the capacitor acts as a weak piezo electric speaker.
Using a 100V drive voltage [Dan] was able to get 300nm of deflection using the capacitor. To extend the range of the actuator he decided to ‘pole the ceramic dielectric’ this involved heating the capacitor above its Curie temperature of 120C. For this he used a transistor to heat the part as an ad-hoc hotplate. This increased the range of the actuator to 800nm, ideal for many STM (and other SPM) systems....
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Check out this round-up of types of audio amplifier circuit from eetimes:

In high-quality audio applications, an analog signal is elaborated to get to the output of a signal with the greatest power at the least possible distortion. There are several basic types of amplifier designs, each having advantages and disadvantages, although Class D amplifiers have emerged because of their low power consumption and low distortion....
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Check out Rulof's wildly inventive junkyard hard drive upcycling project -- he shows you how to turn a discarded HDD into a working microphone! Shared by hackaday:

The drive’s arm and voice coil actuator are the key parts of this project. It was modified with a metal extension so that a paper cone cut from an audio speaker could be attached, an idea used in microphone projects we’ve previously featured. Copper wire scavenged from the speaker was then soldered to voice coil on the arm as well as an audio jack. In the first version of the Hard Drive Microphone, the arm is held upright with a pair of springs and vibrates when the cone catches sound.
While the microphone worked, [Rulof] saw room for improvement. In the second version, he replaced the mechanical springs with magnets to keep the arm aloft. One pair was glued to the sides of the base, while another pair recovered from an old optical drive was affixed to the arm. He fabricated a larger paper cone and added a pop filter made out of pantyhose for good measure. The higher sound quality is definitely noticeable....
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Check out the Proto G's WiFi Smoke Detector tutorial, and read the comments below for discussions of other sensors/detection criteria that might apply to your specific workshop needs:

This is a simple WiFI Smoke Detector that texts me when it senses smoke. I made this for my battery storage area in case of a lithium polymer fire. I still have all of my regular smoke detectors installed and I don't suggest relying only on this, but rather as an extra layer of protection. If I had a house I would install a proper fire alarm system that calls the fire department, but I live in a small apartment so I can't. I can set this one to email and call the local fire department as well(local laws apply). In my county it is allowed as long as you register it with the fire department. Either way, I would rather call the fire department myself when I receive multiple texts.

This solution is much better than only using regular smoke detectors. If something happens while I'm a work, the whole place will burn down. Accidents happen, and when you live in an apartment complex, any one of your neighbors could cause a fire. I live a mile from work so if I receive a text, lives could potentially be saved....

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Chuck Stephens created a tutorial to show how he puts together a breadboard prototyping module to benefit from the advantages of quickly building a circuit on a breadboard with more stability to trusting that the circuit being prototyped hasn't shaken a patch wire or a component loose. Via hackaday.

Breadboards are great for building and modifying circuits. Being able to quickly switch out components helps you see how their values affect the rest of the circuit. Breadboards are an invaluable part of any electronic hobbyists education, but they have their drawbacks. For one thing, the small components used on breadboards are hard to work with. Trim pots, DIP switches and tiny momentary switches are finicky and often come loose at the worst times. I've spent lots of time trouble shooting a circuit only to discover the failure was due to a loose switch or trim pot.
The breadboard prototyping module gives you the versatility of breadboarding with the convenience and 'solidness' of the old style circuit building kits. Switches, pots and other panel mounted components can be easily connected to a breadboarded circuit with common jumper wires, making prototyping a breeze. Here's how to build your own....
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Checkout hipfan75's completed RasPi garage door controller PCB breakout design project. via Dangerous Prototypes.

...The board is a Raspberry Pi (v1, Model B, rev2) breakout also hosting an STM32F030 ARM microcontroller. The uC optionally connects to the Pi's UART with a couple of the Pi's GPIOs used to reset the uC and enter the bootloader. The uC GPIOs are also broken out.

A header connected to the Pi's SPI bus is wired for an NRF24L01+. There is also a header for a 12V boost converter which can power 315 and 433 MHz transmitters. The transmitters are driven by the microcontroller.

The board can get 5V from the Pi or via a micro-USB port. 3.3V is available from the Pi or from an optional ADP122/AP2112 connected to whatever 5V source is selected. There is also an option to drive the 315/433Mhz transmitters via 5V or 12V....

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