State-Aware Foldable Electronics Enters The Third Dimension

July 5, 2015 by Sonya Vasquez No comments

Still working with PCBs in 2D? Not [Yoav]. With some clever twists on the way we fab PCBs, he’s managed to create a state-aware foldable circuit board that responds to different configurations.

From his paper [PDF warning], [Yoav] discusses two techniques for developing foldable circuits that may be used repeatedly. The first method involves printing the circuit onto a flexible circuit board material and then bound front-and-back between two sheets of acrylic. Valid folded edges are distinguished by the edges of individual acrylic pieces. The second method involves laying out circuits manually via conductive copper tape and then exposing pads to determine an open or closed state.

Reconfigurable foldable objects may open the door for many creative avenues; in the video (after the break), [Yoav] demonstrates the project’s state-awareness with a simple onscreen rendering that echoes its physical counterpart.

While these circuits are fabbed from a custom solution, not FR1 or FR4, don’t let that note hold your imagination back. In fact, If you’re interested with using PCB FR4 as a structural element, check out [Voja’s] comprehensive guide on the subject.

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Wood & Glue RepStrap Works Surprisingly Well

July 5, 2015 by Rich Bremer 7 Comments

Even with the cost of 3D Printers continually falling, entering the hobby still requires a significant investment. [Skeat] had some typical 3D Printer components available but didn’t have access to a printer for making the ever-so-common frame parts of typical RepRap designs.

[Skeat’s] plan was to cobble together a printer just good enough to print out parts for another, more robust one. The frame is made from wood, a very inexpensive and available material. The frame is not screwed together and doesn’t have any alignment tabs, it’s just hand cut pieces glued together. Each portion of the frame is laid out, aligned with a carpenter’s square and then glued together. This design and assembly method was intentional as [Skeat] didn’t have access to any precision tools. He stated that the only parts of the frame that had to be somewhat precise were the motor mount holes. The assembly process is well documented to aid anyone else looking to make something similar.

In addition to the wooden frame, all of the components are glued in place. That includes the bearings, rods, limit switches and even the Z axis motor! After seeing the photos of this printer, it would be easy to dismiss it as a poor performer. The below video shows that this printer’s print quality can keep up with any hobby level machine available. We wonder if [Skeat] is rethinking making another since this one works so well.

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Pico Space Balloon Circumnavigates The Globe, Twice

July 5, 2015 by Elliot Williams 13 Comments

We’ve reported on “space” balloons before. Heck, some of us have even launched a few. Usually they go way up in the air, take some cool pictures, and land within driving (and retrieving) distance the same afternoon. You get often amazing photos and bragging rights that you took them for the low, low price of a really big helium balloon and a fill.

But what if you shrunk everything down? Over the last few years, [Andy, VK3YT] has been launching ever smaller and lighter balloons with very low power ham radio payloads. So no camera and no photos, but the payback is that he’s launching payloads that weigh around thirteen grams complete with GPS, radio, solar cell, and batteries. They can stay up for weeks and go really far. We’d love to see some construction details beyond the minimalistic “Solar powered party balloon, 25mW TX”. But that about sums it up.

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Hackaday Prize Entry: Controlling Relays Over WiFi

July 4, 2015 by Brian Benchoff 1 Comment

It’s been less than a year since the ESP8266 WiFi Module was released. This is a chip whose original data sheets were only available in Chinese, could only be controlled through AT commands, and was (originally) only sold through Seeed Studio and other various Chinese retailers. It had one thing going for it: it was five dollars. For the price of a crappy sub, you can blink an LED from the Internet. Needless to say, the ESP8266 is now very popular.

There are a lot of ESP8266 projects in The Hackaday Prize this year, and [David]’s project is making great use of the relatively meager pinout of this module. He’s built an 8-channel relay controller with a WiFi interface to control industrial equipment. It’s a great project, but just of many ESP projects in the prize this year.

The ESP doesn’t have a huge number of pins, but there are enough for some serious work with the right hardware. He’s using the ESP-12 module to get the most pins, and using an SPI port expander to drive an octet of relays. It’s a simple board, but everything you need to control a bunch of relays over WiFi is right there: LEDs, reset buttons, and RS232 level conversion.

You can check out a pair of very satisfying videos of relays clicking below.

The 2015 Hackaday Prize is sponsored by:

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High Voltage, Wood And Resin Result In Fractal Art

July 4, 2015 by Dan Maloney 37 Comments

Wood burning, which goes by pyrography when it’s feeling fancy, has been an art form for centuries. [PapaJ06] puts a new twist on it by using a microwave oven transformer to generate fractal patterns in wood. We’ve seen these Lichtenberg figures before, but generally as electric discharges in acrylic sheets or crystal balls using multi-mega-electron volt accelerators. [PapaJ06]’s technique is considerably simpler and well within the reach of most would-be fractal artists, relying as it does on a transformer salvaged from a $20 Craigslist microwave.

But the extra twist that really brings the wow factor to the fractal patterns burned into the wood is the addition of some phosphorescent resin to fill the valleys carved by the electric discharge. [PapaJ06] carefully prepares the wood, fills the burns with glow powder mixed with epoxy resin, and finishes with a little sanding, linseed oil and polyurethane. The contrast between the charred and intact wood, and the way the resin fills the voids really brings out the fractal nature of the Lichtenberg figures.

[PapaJ06] doesn’t really show us too much about his process, but luckily [TheBackyardScientist] recently posted a video of his process for riding the lightning. Check it out after the break.

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Exploding Multimeter Battle Royale

July 4, 2015 by Brian Benchoff 25 Comments

If you check out eBay, Amazon, or the other kinda-shady online retailers out there, you’ll quickly find you can buy a CAT III (600V) rated multimeter for under $50. If you think about it, this is incredible. There’s a lot of engineering that needs to go into a meter that is able to measure junction boxes, and factories in China are pushing these things out for an amazing price.

Over on the EEVBlog, these meters are being pushed to the limits. Last month, [joeqsmith] started a thread testing the theory that these cheap meters can handle extremely high voltages. A proper CAT III test requires a surge of electrons with a 6kV peak and a 2 ohm source. With a bunch of caps, bailing wire, JB Weld and zip ties, anyone can test if these meters are rated at what they say they are. Get a few people on the EEVBlog sending [joeqsmith] some cheapo meters, and you can have some real fun figuring out how these meters stack up.

The real experiments began with [joe smith]’s low energy surge generator, a beast of a machine that can be measured with an even beastlier high voltage scope probe. This is a machine that will send a voltage spike through anything to short out traces on poorly designed multimeters.

How did the cheapo meters fare? Not well, for the most part. There was, however, one exception: the Fluke 101. This is Fluke’s My First Multimeter, stuffed into a pocketable package. This meter is able to survive 12kV pulses when all but two of the other brands of meters would fail at 3kV.

What’s the secret to Fluke’s success? You only need to look at what the Fluke 101 can’t do. Fluke’s budget meter doesn’t measure current. If you ever look inside a meter, you’ll usually find two fuses, one for measuring Amps and the other for all the other functions on the scope. There’s quite a bit of engineering that goes into the current measurement of a meter, and when it goes wrong you have a bomb on your hands. Fluke engineers rather intelligently dropped current measurement from this budget meter, allowing them to save that much on their BOM.

There’s an impressive amount of data collected by [joeqsmith] and the other contributors in this thread, but don’t use this to decide on your next budget meter; This is more of an interesting discovery of how to make a product that meets specs: just cut out what can’t be done with the given budget.

Ducted Fan Drone Flies

July 4, 2015 by Anool Mahidharia 19 Comments

A while back, we wrote about the ducted fan, single rotor, VTOL drone that [Armin Strobel] was working on. It wasn’t quite finished then, and hadn’t got off the ground yet. He’s posted an update, and from the looks of it, he’s made tons of progress, including a first flight with successful take-off and landing.

The successful flight was no coincidence. Tuning any kind of ‘copter is a tricky business. Handling them manually during testing could be outright dangerous. So he built two different test-beds from pieces of wood, some 3D printed parts and bearings. One lets him mount the drone and tune its pitch (and roll), while the other lets him tune the yaw parameters. And just like they do in wind tunnel testing, he fixed short pieces of yarn at various points on the air frame to check for turbulence. Doing this also gave him some insight into how he could improve the 3D printed air-frame in the next iteration. He repeated the tests on the two test beds, going back and forth to make sure the tuning parameters were not interfering with each other. He also modified the landing gear to improve stability during take-off and landing and to prevent tipping. [Armin] is using the PixHawk PX4 for flight control and a BeagleBone Black for higher level functions and control.

Once the first flight showed that the drone could do stable flight, he attached a Go-Pro and recorded some nice video on subsequent flights. The next steps are to fine tune the flight control parameters to ensure stable hovering with position hold and way point following. He may also 3D print an improved air-frame. For details about the build, check out our earlier blog post on the Ducted Fan Drone. Check out the two videos below – one showing the first flight of the Drone, and the other one about the test beds being used for tuning.

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