This Is Your Last Chance To Design The Greatest In Power Harvesting

July 13, 2018 by 17 Comments

This is your last weekend to get your project together for the Power Harvesting Challenge in this year’s Hackaday Prize. We’re looking for projects that harvest energy from the ether, and power electronics from solar, thermal, wind, light, or random electromagnetic fluctuations. Is it going to save the world? Maybe, but it’s a great excuse to build some really cool electronics. If you have an idea in mind, this is your last weekend to enter it in the Power Harvesting Challenge.

The Hackaday community has thrown itself full-force into the Hackaday Prize, and there are hundreds of projects entered in this year’s Prize. Next week, we’ll choose the top twenty projects entered during the Power Harvesting Challenge to advance to the finals. Each of those twenty projects will be awarded $1,000 and be in the running to win the Grand Prize of $50,000 and four other top cash prizes.

This is your last chance to get in on the Power Harvesting Challenge in this year’s Hackaday Prize. For this challenge, we’re looking for projects that harvest energy from any source. It could be a module, or as a distinct design easily incorporated into other builds. Don’t wait — start your entry now.

The Power Harvesting Challenge ends a 07:00 AM PDT on July 16th. Afterwards, we’ll be continuing on into Human-Computer Interface and Musical Instrument Challenges. This is your shot to get your project in the finals in the Hackaday Prize. Don’t miss out!

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ERRF 18: New Products Make Their Debut

July 13, 2018 by 6 Comments

While ostensibly the purpose of the recent East Coast RepRap Festival (ERRF) was to celebrate the 3D printing community and culture, it should come as no surprise that more than a few companies decided to use the event as an opportunity to publicly launch new products. Who can blame them? It’s not as if every day you have a captive audience of 3D printing aficionados; you might as well make the best of it.

Many creations were being shown off for the first time at ERRF, and we surely didn’t get a chance to see them all. There was simply too much going on at any given time to be sure no printed stone was left unturned. But the following printers, filaments, and accessories caught our attention long enough to warrant sharing with the good readers of Hackaday.

Keep in mind that much of this information is tentative at best, and things could easily change between now and when the products actually go on sale. These events serve as much as a sounding board for new products as they do a venue for advertising and selling them, so feedback received from show attendees may very well alter some of these products from what we saw at ERRF.

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Supersize DIY R/C Servos From Windscreen Wipers

July 13, 2018 by 26 Comments

We’re all familiar with the experience of buying hobby servos. The market is awash with cheap clones which have inflated specs and poor performance. Even branded servos often fail to deliver, and sometimes you just can’t get the required torque or speed from the small form factor of the typical hobby servo.

Enter [James Bruton] and his DIY RC servo from a windscreen wiper motor. Windscreen wiper motors are cheap as chips, and a classic salvage. The motor shaft is connected to a potentiometer via a pulley and some string, providing the necessary closed-loop feedback. Instead of using the traditional analog circuitry found inside a servo, an Arduino provides the brains. This means PID control can be implemented on the ‘duino, and tuned to get the best response from different load characteristics. There’s also the choice of different interfacing options: though [James]’ Arduino code accepts PWM signals for a drop-in R/C servo replacement, the addition of a microcontroller means many other input signal types and protocols are available. In fact, we recently wrote about serial bus servos and their numerous advantages.

We particularly love this because of the price barrier of industrial servomotors; sure, this kind of solution doesn’t have the precision or torque that off-the-shelf products provide, but would be sufficient for many hacks. Incidentally, this is what inspired one of our favourite open source projects: ODrive, which focuses on harnessing the power of cheap brushless motors for industrial use.

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Behind The Pin: How The Raspberry Pi Gets Its Audio

July 13, 2018 by 54 Comments

Single board computers have provided us with a revolution in the way we approach computing as hardware creators. We have grown accustomed to a world in which an entire microcomputer has become a component in its own right rather than a complex system, and we interface to them as amorphous entities through their exposed interfaces. But every pin or socket on a single board computer has something behind it, so following up on a recent news-inspired item in which we took a look at what lies behind the Ethernet jack on a Raspberry Pi, we’d like to continue that theme by looking behind more pins and interfaces. So today we’ll stay with the Raspberry Pi, and start with an easy target by taking a look down its audio jack.

All the main Raspberry Pi board releases since 2012 with the exception of the Pi Zero series, have featured a 3.5mm jack carrying line-level audio. The circuits are readily accessible via the Raspberry Pi website, and are easy enough to understand because of course all the really hard work is done within the silicon of the Broadcom system-on-chip. Looking at the audio circuitry, we’ll start by going back to the original Pi Model B from 2012 (PDF) because though more recent models have seen a few changes, this holds the essence of the circuitry.

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Replace Your Calipers With A Microscope And Image Analysis

July 13, 2018 by 19 Comments

Getting a good measurement is a matter of using the right tool for the job. A tape measure and a caliper are both useful tools, but they’re hardly interchangeable for every task. Some jobs call for a hands-off, indirect way to measure small distances, which is where this image analysis measuring technique can come in handy.

Although it appears [Saulius Lukse] purpose-built this rig, which consists of a microscopic lens on a digital camera mounted to the Z-axis of a small CNC machine, we suspect that anything capable of accurately and smoothly transitioning a camera vertically could be used. The idea is simple: the height of the camera over the object to be measured is increased in fine increments, with an image acquired in OpenCV at each stop. A Laplace transformation is performed to assess the sharpness of each image, which when plotted against the frame number shows peaks where the image is most in focus. If you know the distance the lens traveled between peaks, you can estimate the height of the object. [Salius] measured a coin using this technique and it was spot on compared to a caliper. We could see this method being useful for getting an accurate vertical profile of a more complex object.

From home-brew lidar to detecting lightning in video, [Saulius] has an interesting skill set at the intersection of optics and electronics. We’re looking forward to what he comes up with next.

Give The Clapper A Hand

July 13, 2018 by 8 Comments

While “The Clapper” probably first conjures images of low-budget commercials, it was still a useful way to remotely switch lights and other things around the house. But if the lights you want to switch weren’t plugged into the wall, like a ceiling fan, for example, The Clapper was not going to help you. To add some functionality to this infamous device, [Robin] built one from scratch that has all the extra features built in that you could ever want.

First, the new Clapper attaches to the light switch directly, favoring mechanical action of the switch itself rather than an electromechanical relay which requires wiring. With this setup, it would be easy to install even if you rent an apartment and can’t do things like rewire outlets and it has the advantage of being able to switch any device, even if it doesn’t plug into the wall. There’s also a built-in microphone to listen for claps, but since it’s open-source you could program it to actuate the switch when it hears any sound. It also includes the ability to be wired in to a home automation system as well.

If the reason you’ve stayed out of the home automation game is that you live in a rental and can’t make the necessary modifications to your home, [Robin]’s Clapper might be just the thing you need to finally automate your living space. All the files are available on the project site, including the 3D printing plans and the project code. Once you get started in home automation, though, there’s a lot more you can do with it.

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Old Time Traffic Signal Revived With A Raspberry Pi Controller

July 12, 2018 by 28 Comments

Anyone with even a passing familiarity with the classic animated shorts of the 1940s will recognize the traffic signal in the image above. Yes, such things actually existed in the real world, not just in the Looney world of [Bugs Bunny] et al. As sturdy as such devices were, they don’t last forever, though, which is why a restoration of this classic Acme traffic signal was necessary for a California museum. Yes, that Acme.

When you see a traffic signal from the early days of the automotive age like this one, it becomes quickly apparent how good the modern equivalent has become. Back in the day, with a mix of lights distributed all over the body of the signal, arms that extend out, and bells that ring when the state changes, it’s easy to see how things could get out of hand at an intersection. That complexity made the restoration project by [am1034481] and colleagues at the Southern California Traffic Museum all the more difficult. Each signal has three lights, a motor for the flag, and an annunciator bell, each requiring a relay. What’s more, the motor needs to run in both directions, so a reversing relay is needed, and the arm has a mechanism to keep it in position when motor power is removed, which needs yet another relay. With two signals, everything was doubled, so the new controller used a 16-channel relay board and a Raspberry Pi to run through various demos. To keep induced currents from wreaking havoc, zero-crossing solid state relays were used on the big AC motors and coils in the signal. It looks like a lot of work, but the end results are worth it.

Looking for more information on traffic signal controls? We talked about that a while back.