Animated EV Charge Cable Enlightens Us

December 28, 2016 by Lewin Day 14 Comments

[ch00f] was searching for an idea to build for his father this Christmas, and cast his gaze across those novelty phone charging cables that have “flowing” LEDs along their length. Not one to stick to the small scale, he set out to create a flowing LED effect for a Tesla EV charger.

The basic components behind the build are a current transformer, a NeoPixel LED strip, and an ATtiny44 to run the show. But the quality of the build is where [ch00f]’s project really shines. The writeup is top notch — [ch00f] goes to great lengths showing every detail of the build. The project log covers the challenges of finding appropriate wiring & enclosures for the high power AC build, how to interface the current-sense transformer to the microcontroller, and shares [ch00f]’s techniques for testing the fit of components to ensure the best chance of getting the build right the first time. If you’ve ever gotten a breadboarded prototype humming along sweetly, only to suffer as you try to cram all the pieces into a tiny plastic box, you’ll definitely pick something up here.

Perhaps you’d like to check out this teardown of a Tesla Model S battery. Video after the break.

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The Tiny SCSI Emulator

December 25, 2016 by Lewin Day 36 Comments

For fans of vintage computers of the 80s and 90s, SCSI can be a real thorn in the side. The stock of functioning hard drives is dwindling, and mysterious termination issues are sure to have you cursing the SCSI voodoo before long. Over the years, this has led to various projects that aim to create new SCSI hardware to fill in where the original equipment is too broken to use, or too rare to find.

[David Kuder]’s tiny SCSI emulator is designed for just this purpose. [David] has combined a Teensy 3.5 with a NCR5380 SCSI interface chip to build his device. With a 120MHz clock and 192K of RAM, the Teensy provides plenty of horsepower to keep up with the SCSI signals, and its DMA features don’t hurt either.

Now, many earlier SCSI emulation or conversion projects have purely focused on storage – such as the SCSI2SD, which emulates a SCSI hard drive using a microSD card for storage. [David]’s pulled that off, maxing out the NCR5380’s throughput with plenty to spare on the SD card end of things. Future work looks to gain more speed through a SCSI controller upgrade.

But that’s not all SCSI’s good for. Back in the wild times that were the 80s, many computers, and particularly the early Macintosh line, were short on expansion options. This led to the development of SCSI Ethernet adapters, which [David] is also trying to emulate by adding a W5100 Ethernet shield to his project. So far the Cabletron EA412 driver [David] is using is causing the Macintosh SE test system to crash after initial setup, but debugging continues.

It’s always great to see projects that aim to keep vintage hardware alive — like this mass repair of six Commodore 64s.

Instant Camera With This Year’s Hottest Dithering Technique

December 24, 2016 by Lewin Day 25 Comments

Digital cameras are great, because you can take thousands of pictures without running out of film. But there’s something to be said for having a tangible image you can hold in your hand. The Polaroid cameras of yesteryear were great for this, but now they’re hard to find and the price per photograph is ludicrously expensive.

dither — Dithering allows the camera to print a much better image.

Over the past few years, a few people have sought a way to create printed photographs at a lower cost. One of the best ways to do this is to find something much cheaper than Polaroid film — like thermal paper.

[Fabien-Chouteau]’s thermal printing camera isn’t the first — you’ve got the Gameboy Camera/Printer and a few others to thank for that. But it’s a great example of the form. The camera combines an Adafruit thermal receipt printer with an OpenMV camera, both easily sourced, if not exactly cheap. It even adds a ST7735 LCD for live display of the camera’s image, just like consumer-grade cameras!

It’s not just a slapped together kludge of parts bin components, however. While the thermal printer is only capable of printing black or white pixels, its resolution is much higher than the image from the camera. This allows the camera to use a 3×3 block of printed pixels to represent a single pixel from the camera, and with some fancy dithering techniques, can emulate shades of grey quite effectively. It’s tricks like this that really add polish to a project, and make a big difference to the picture quality at the end of the day.

It’s not the first thermal printer camera we’ve seen – [Ch00f]’s woodgrain instant camera build highlighted the issues of careful camera selection when pursuing this type of build.

Video after the break.

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Lo-Fi Greeting Card Sampler

December 24, 2016 by Lewin Day 8 Comments

We’re all familiar with record-your-own-message greeting cards. Generally they’re little more than a cute gimmick for a friend’s birthday, but [dögenigt] saw that these cards had more potential.

After sourcing a couple of cheap modules from eBay, the first order of business was to replace the watch batteries with a DC power supply. Following the art of circuit bending, he then set about probing contacts on the board. Looking to control the pitch of the recorded message, [dögenigt] found two pads that when touched, changed the speed of playback. Wiring these two points to the ears of a potentiometer allowed the pitch to be varied continously. Not yet satisfied, [dögenigt] wanted to enable looped playback, and found a pin that went low when the message was finished playing. Wiring this back to the play button allowed the recording to loop continuously.

[dögenigt] now has a neat little sampler on his hands for less than $10 in parts. To top it off, he housed it all in a sweet 70s intercom enclosure, using the Call button to activate recording, and even made it light sensitive with an LDR.

We’ve seen a few interesting circuit bends over the years – check out this digitally bent Roland TR-626 or this classic hacked Furby.

Check out the video under the break.

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Raspberry Pi Camera Flash

December 22, 2016 by Lewin Day 9 Comments

The Raspberry Pi Camera is a great tool; it allows projects that require a camera to be put together quickly and on a budget. Plus, having a Linux back end for a little processing never hurt anybody. What can be difficult however, is imaging in low light conditions. Most smartphones have an LED flash built in for this purpose. [Wim Van Gool] decided to follow suit and build an LED flash for the Raspberry Pi.

The project consists of a custom PCB with surface-mount LEDs in an attractive concentric layout. This is a good way to get a nice even distribution of light, particularly when taking photos close up. The board is designed around the Texas Instruments TPS61169 LED driver, which is controlled by a PWM signal from the Raspberry Pi. The flash mounts as a Raspberry Pi HAT, and there’s a hole routed in the centre to allow the camera to fit in nice and snug when using standard 11mm standoffs. It might seem simple, but it’s an impressively tidy piece of engineering and a testament to [Wim]’s abilities.

The Raspberry Pi Camera turns up in all sorts of projects — like these far-seeing PiNoculars.

3D Printed Greeting Cards

December 20, 2016 by Lewin Day 8 Comments

T’is the season to hack, and the maker brigade won’t disappoint — there’s no better way to crank out a few cute holiday tchotchkes than to fire up the 3D printer. [Niklas Roy] has released gDraw, a software package that creates G-code to print out 2D drawings on your 3D printer.

The interface is simple, allowing the quick and easy creation of basic vector drawings. The program then converts the paths in the drawing to a G-code representation that your printer follows to squirt them out in plastic. Think of it as the 3D printed equivalent of the “Stroke Path” tool in Photoshop.

[Niklas] chose to demonstrate the software by creating some interesting greeting cards that Big Christmas is sure to rip off next year and sell for $30 a pop. The printed plastic drawings give a fun 3D effect to the cards, and we’d love to see more examples of art created with this technique. The software was designed to work with the Ultimaker 2, but with tweaks, it should be able to generate code for other printers, too.

We’ve seen plenty of great festive hacks over the years — like this awesome laser projection setup.

Hedgefund Startup Powered By Crowdsourced Code

December 19, 2016 by Lewin Day 17 Comments

In the financial sector, everyone is looking for a new way to get ahead. Since the invention of the personal computer, and perhaps even before, large financial institutions have been using software to guide all manner of investment decisions. The turn of the century saw the rise of High Frequency Trading, or HFT, in which highly optimized bots make millions of split-second transactions a day.

Recently, [Wired] reported on Numerai — a hedge fund founded on big data and crowdsourcing principles. The basic premise is thus — Numerai takes its transaction data, encrypts it in a manner that hides its true nature from competitors but remains computable, and shares it with anyone who cares to look. Data scientists then crunch the numbers and suggest potential trading algorithms, and those whose algorithms succeed are rewarded with cold, hard Bitcoin.

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