Building The Brightest Light Sabre In The World

October 25, 2016 by Jenny List 18 Comments

If you are looking for a Star Wars light sabre, sometimes your choices can be a little disappointing. “Replica” sabres from toy and novelty vendors may superficially look the part, but with their tinny speakers and lacklustre show of LEDs they often have less of the Force about them and more of the Farce.

[Jeremy Lee] offers a solution; he’s built what he claims to be the brightest light sabre in the world. That’s a bold assertion, and one which we think might even throw down a gauntlet to other sabre builders and spark an arms race among Jedi wannabes.

The super-bright sabre uses a 144 LED double-sided strip of Neopixels in a polycarbonate tube, with a DC to DC converter powered by a 1000mAH LiPo battery. Sound effects come from a SparkFun Pro Micro powering a 2W speaker through a small audio amplifier. The handle meanwhile is constructed from PVC pipe fittings.

His first attempt at the sabre had the LEDs at full power, and promptly melted his tube. Thus the final version runs at 40% of its maximum rating, with a “burst” mode for those moments at which combat demands it.

His write-up is a series of posts, with plenty of video at all points. It might seem odd to show you the shortest of them here at only a few seconds long, but since the unique selling point is its brightness we think the best way to show that is at night.

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A Vintage Single Transistor LED Blinker

October 17, 2016 by Rich Hawkes 19 Comments

[Eric Wasatonic] had a box of SWB2433 transistors that he had very little information about. In order to discover their properties, he fired up his curve tracer to compare these transistors with more common ones. He noticed the SWB2433 exhibited negative resistance while the similar curves of a 2n3904 didn’t. Then he reverse-biased the two transistors: the negative resistance region on the 2n3904 was less than that of the SWB2433, but it was there, and a 2n2222 had a bigger region. Using this knowledge, he developed a relaxation oscillator circuit which uses a negatively biased transistor.

Using one transistor, one resistor and one capacitor, he describes the circuit and how the components affect the frequency of the sawtooth wave the oscillator creates. [Eric] uses the oscillator to build a simple LED blinker and shows what happens when he changes the transistor and adjusts the voltage or resistance. He also shows the circuit as a tone generator and adjusts the tone by replacing the resistor with a potentiometer. And then, for fun, he modifies the circuit to show the oscillator as an AM transmitter. Check out his video after the break.

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Blinking An LED – Extreme Edition

October 13, 2016 by Nava Whiteford 57 Comments

This hacker’s video on blinking LEDs never got the recognition it deserves. At the time of writing clocking in at just 61 views, but it is indeed a work of art. Just trust me, scroll to the bottom of the article and watch it, you wont be disappointed.

Not convinced? OK, let me tell you about it and the world it has opened up in the Japanese maker scene. We’ve all blinked an LED. Maybe it was just to test a microcontroller, like the simplest Arduino example.

Or we’ve been a tad more old school and used the classic 555 to do it. Or maybe like me, you went through a phase of hacking together Phase Shift and other oscillators because well… it’s fun!

But [Junichi AKITA] has more extreme tastes, deciding that a custom IC layout is the way to go. [Junichi] designed a ring oscillator composed of flip-flops, then hand laid out each MOSFET placing each layer exactly where it should be fabricated.

The resulting design was then fabricated by an academic shuttle service in Japan (a bit like the well known MOSIS service). The result is a tiny circuit in the top right corner of the IC. Which of course [Junichi] then had to wirebond (check the video for a cool 1980s style Westbond machine which are still hugely popular in Japan).

IC Layout… by hand!

Optical image of the fabricated circuit.

[Junichi] bonded the die directly to a PCB (COB). I assume, purely for irony, a 555, and ATtiny based oscillator were also laid out on the board.

I guess you might have a couple of lingering questions. First you’ll likely bemoan your lack of your own fabrication facility (I’m still eyeing those used 1 micron fab lines that crop up on eBay from time to time). And secondly you might be asking yourself… why?

Both these questions are somewhat answers by the MakeLSI project. This growing project in Japan seems to have opened up semiconductor fabrication to all kinds of projects.

While my Japanese isn’t good enough to fully understand what’s happening it’s clear there are many awesome projects going on. Including joys such as IC layouts designed in vector graphics packages (Inkscape) and die images packed with interesting layouts, anime characters and QR codes.

For more awesome images and information (unfortunately all in Japanese) you can check them out on Facebook or on their homepage.

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Blooming Flower Lamp Will Test Your 3D Printer

October 11, 2016 by Gerrit Coetzee 11 Comments

[ossum] has a baby on the way. He admits that he got a bit carried away, brimming with parental excitement. What resulted is a fully articulated LED WiFi lamp that blooms and glows dramatically in the friendly confines of the oncoming baby’s room.

We’ve covered [ossum]’s work before. As usual, he started off by showing his complete mastery of Fusion360 and making the rest of us look bad. If you want to learn 360, we recommend scrobbing through his models to see how it’s done. The base encloses an ESP8266 and a hobby servo. A clever mechanism pulls down on a stranded steel cable that runs through the stem along with some control lines for the LEDS. This opens and closes the petals. The LEDs are all held in a 3D printed frame which produces a nice even glow.

If you’d like to build one yourself, there’s a full video viewable after the break. Files are available on Thingiverse. Just make sure you tune up your printer first, this is a tough one.

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64×16 LED MQTT Laundry Display

October 11, 2016 by Rich Hawkes 2 Comments

When you have an MQTT broker receiving messages, you want to be able to see them. [Xose Pérez] already had a system set up that sent him notifications, but he had a pair of 32×16 LED matrices, so he decided to make a big, bright sign to let him know when he got an important message sent to the broker.

[Xose Pérez] had already built a laundry monitor which was sending messages to an MQTT broker so he wouldn’t forget his laundry sitting in the washing machine. To communicate with the broker, he used an ESP-12. He had already ported an Arduino library for the Holtek HT1362C display drivers used by the matrices to work with his driver board.

He wanted to try out SMD soldering so he built a custom PCB to hold the ESP-12, power supply, passive components, and a connector and he describes his methods and results. Instead of hardcoded messages, he wanted the system to be configurable and display messages coming in, not only from his laundry system, but also from other sensors. A web interface, built with jQuery and WebSockets, running on the ESP-12 allows the user to subscribe to a topic on the broker and show a customized name and value on the display when a payload is available.

All-in-all, [Xose Pérez] has posted a great tutorial in which he goes over the hardware he built, the libraries he used, SMD soldering, how he made the enclosure, and even his choice in IDE (PlatformIO). He also posted the software, board designs and enclosure models software and hardware on bitbucket. The end result is a great looking LED matrix that displays not only his laundry’s status, but also anything else he wants to from his MQTT broker.

If you want to try your hand with MQTT, the ESP8266 is a wonderful device for sensor nodes, and any Linux box (like the Raspberry Pi) makes an easy broker. Check out [Elliot Williams’] Minimal MQTT series and you will be up and running in no time.

Slide Viewer Upgrade Is A Bright Idea

October 9, 2016 by Kristina Panos 6 Comments

[cunningfellow] has been putting LEDs in everything lately. That’s understandable. Most recently, he used them to drastically upgrade his father’s super-cool mid-century slide viewer.

The slide viewer used to use a flashlight bulb, but it didn’t light evenly at all. Not only that, it produced a dim, orange-ish light. [cunningfellow] happened to have an old Nokia N93 lying around and decided to cannibalize that strange, beautiful, swiveling flip phone for its backlight circuitry. Unfortunately, the 4 LEDs aren’t going to run on a pair of C cells like the flashlight bulb did. [cunningfellow] needed some kind of boost converter.

He found one in the form of a Nokia E73 LCD driver board created by [Andy Brown]. The LEDs are way brighter than that old incandescent bulb, and they draw about 10mA less to boot. We think [cunningfellow]’s father will be happy with the result.

If you have an old slide viewer and no slides, try using it as a project case. If this post makes you miss your View-Master (also understandable), you can always turn your phone into a stereopticon.

DIY Plant LED Light Prototype Lights Up The Winter

October 8, 2016 by Richard Baguley 25 Comments

With winter on the way, our thoughts turn to indoor hacks. And what could be better in the cold winter than fresh veggies? This can be done by replacing the sun with an LED light, and [Margaret Johnson], aka [Bitknitting] has been working on building her own LED plant light.

She’s using a combination of red and blue LEDs that produce the ratio of light frequencies that plants thrive on, and has been experimenting with how bright to make them and how long to run them. This combination of factors determines how much light the plants get every day, called the Daily Light Integral, or DLI, and has a huge effect on how well the plants grow.

Her latest prototype uses nine red and two blue 3 Watt LEDs which run for about twenty hours a day. These lights shine onto the growing area, a bucket filled with nutrient solution. [Margaret] has done an excellent job of outlining why and how she made the choices she did and providing lots of links to more information for the home grower. It’s a great place to start for anyone looking to get something growing indoors in the depths of winter.