The Flowing Pixels Of Time Wait For No Man

January 28, 2016 by Rud Merriam 14 Comments

The hourglass dramatically depicts the flow of time; gravity pulling grains of sand inevitably downward. So it is with the Bits of Time project by [Frank Andre]. The pixels drop, stopping only when the battery dies. Or, when your eggs are ready. (Pssst, it’s also on Hackaday.io.)

The project starts with a couple of [Frank’s] PixBlocks. A processor is added to one PixBlock to serve as the controller for both after they are connected via the serial bus. A tilt switch, with a debouncing circuit, is connected to an IO pin. This tells the processor the orientation of the box and therefore which way the pixels should flow.

Two switches set the duration of the timer in 15 second increments. A third starts the timer. When the box is rotated the pixels start flowing in the opposite direction. With code available on GitHub the system can be programmed for other effects such as changing colors, flickering, or even text display.

You’ll agree this is a bit less intimidating than the MacGyver-ish kitchen timer we covered last year.

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Super Slick, Super Portable Styrofoam Slicer

January 28, 2016 by Dan Maloney 12 Comments

[The King of Random] always seems to have something fun going on in his shop, and his builds tend to be impressively complete. No exception to that rule is his recent hot-wire foam cutter that looks like a ton of fun both to build and to use.

Starting with a simple PVC tubing frame to form the bow of the cutter, the rig ends up looking a little like a scroll saw when [Random] is done with it. A generous work surface sits atop a wood frame, which houses the electrics. A light dimmer and step-down transformer control the cutting wire’s temperature, and the bow even pivots to allow the wire to make miter cuts. A nice final touch is that the frame holding the bow detaches from and store inside the base, making the whole thing portable. It even runs off solar or batteries if you need to work off-grid, which might be handy for quick repairs on the R/C flight line.

Speaking of R/C, check out these hot-wire cut foam airplane wings. And the completeness of this build gets us thinking about the potential for CNC foam cutters.

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The Price Of Space

January 28, 2016 by Al Williams 61 Comments

Many engineers of a certain age have one thing in common: Their early interest in science and engineering came from watching the US and Russian space programs. To me, regardless of any other benefit from the space program (and there are many), that ability to inspire a future generation of engineers made the entire program worthwhile.

We live in a world where kids’ role models are more likely to be sports or entertainment figures that have regular visits to police stations, jails, and rehab centers. The value of having role models that “do science” is invaluable.

This time of the year is a dark time for NASA missions, though. On January 27, 1967, the Apollo I crew (Grissom, White, and Chaffee) died in a fire. The investigation led to NASA limiting how much Velcro you can use in a cabin and moving away from pure oxygen in the cabin.

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Two Portable Oscilloscopes: Shootout

January 28, 2016 by Al Williams 3 Comments

Last time I introduced you to two relatively inexpensive and somewhat portable scopes: the EM125, which is a cross between a digital voltmeter and an oscilloscope, and the Wave Rambler, which is a scope probe with a USB connector attached. Both of the devices cost about $100, and both have their plusses and minuses.

This time, though, I wanted actually to look at some real-world signals. To make that easy, I grabbed yet another scope-like thing I had handy: an Embedded Artists Labtool. This is an interesting board in its own right. It is an LPC-Link programmer attached to an LPC ARM board that has several high-speed A/D channels. However, I’m not using any of that capability for now. The board also has a cheap ARM processor (an LPC812) on it that serves only to generate test signals. The idea is you can use the Labtool in a classroom with no additional equipment.

The Labtool’s demo CPU generates a lot of different signals, but with only one channel on the test scopes, it didn’t make sense to look at, for example, I2C data. So I stuck with two different test signals: a varying pulse width modulation signals and a serial UART transmitter.

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Homemade Bulletproof Glass, Built And Tested

January 28, 2016 by Dan Maloney 35 Comments

Hackers tend to stash away lots of stuff that seems useless, right up until it saves the day. This includes not just junk in our parts bin but brains full of tips and tricks for the shop. With that in mind, you might want to file away a few of the tips in [AvE]’s video of how he made bulletproof glass for a rainy day.

By his own admission, [AvE]’s video is a little disjointed, and the topic of the bulletproof glass is only covered at the beginning and again briefly at the end. Most of the video concerns the machining of a stout stand for the glass for testing on the range. There’s plenty to learn from the machining, though, and [AvE] is always good for a laugh, so the video is worth a watch. The bulletproof glass itself is part of a long-term project that [AvE] is releasing first to his Patreon patrons – a ridiculously over-built flashlight dubbed “The Midnight Sun”. His first two tries at laminating the Lexan discs were less that optimal, as both brands of cyanoacrylate glue clouded the polycarbonate. Stay tuned to the end of the video for the secret of welding Lexan together into an optically clear sandwich.

As for testing under fire, [AvE] sent the rig off to buddy [TAOFLEDERMAUS] for the hot lead treatment. The video after the break shows that the glass is indeed bulletproof, as long as the bullet in question is a .22LR. Not so much for the 9mm, though – that was a clear punch-through. Still, pretty impressive performance for homebrew.

If you want something that can stop an arrow, there’s a lot of materials science to be learned from the ancient Greeks.

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Beautiful And Bizarre Boards

January 28, 2016 by Nava Whiteford 49 Comments

weirdboard — An odd board (piezo coupler), fabbed by OSHPark.

Recently I’ve been getting curious about interesting PCB shapes. In the past I’ve always used simple Polygons, perhaps rounding out the corners to make the design a little more aesthetically pleasing. The board to the right was my introduction to the possibilities of oddly shaped boards. It’s designed to couple with a piezo buzzer (used as an actuator). I’ve been planning to have it fabricated out of FPC (Flexible Printed Circuits), but with fabrication being so cheap I sent it to OSHPark to see what they’d make of it. OSHPark doesn’t have hard specs around internal routing, but in my experience they’re up to try anything (and they’re quality is always great). The width of the prongs on the PCB shown is 5mm. I figured it was a risk, and that it was likely the FR4 could break, but it came back great!

This has led me to the realization that my boards could look much more exciting than they do currently, and that our highly optimized modern PCB fabrication process provides a lot of room for experimentation. This article will discuss some of the options available when creating non-traditional PCBs.

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Rube Goldberg PC/Console Game Hack

January 28, 2016 by Elliot Williams 19 Comments

There’s no holy war holier than establishing whether PC games are superior to console games (they are). But even so, there’s no denying that there are some good console titles out there. What if you’d still like to play them using a mouse and keyboard? If you’re [Agent86], you’d build up the most ridiculous chain of fun electronics to get the job done.

Now there is an overpriced off-the-shelf solution for this problem, and a pre-existing open-source project that’ll get the same job done for only a few bucks in parts. But there’s nothing like the fun in solving a problem your own way, with your own tangle of wires, darn it all! The details of the build span four (4!) pages in [Agent86]’s blog, so settle down with a warm cup of coffee.

Here’s the summary: an Xbox 360 controller is taken apart and turned into an Xbox controller. The buttons and joysticks are put under computer control via a Teensy microcontroller. GPIOs press the controller’s buttons, and digipots replace the analog sticks. Software on the Teensy drives the digipots and presses the buttons, interpreting a custom protocol sent over USB from the computer, which also gets some custom software to send the signals.

So if you’re keeping score: a button press on a keyboard is converted to USB, sent to a PC, converted to a custom serial protocol, sent to a Teensy which emulates a human for a controller that then coverts the signals back into the Xbox’s USB protocol. Pshwew!

Along the way, there’s learning at every stage, which is really the point of an exercise like this. And [Agent86] says that it mostly works, with some glitches in the mouse-to-joystick mapping. But if you’re interested in any part of this crazy chain, you’ve now got a model for each of them.