Year: 2011

LED Wand For Light Painting Photography

July 11, 2011 by 8 Comments

[Michael Ross] is a photographer who has been getting into light painting recently. He’s come up with his own RGB light wand to create some amazing images, and also written a very, very thorough tutorial (PDF warning) on how to build your own light wand.

The light wand is based on an Arduino Mega board and uses an RGB LED strip based on the HL1606 controller chip. We’ve covered these LED strips before, and they’re very easy to use with the requisite library. So far, [Michael] has built a 48-LED light wand and a 16-LED wand with a 6-position program selector, making it easy to do awesome single-exposure photos like this.

[Michael] creates his images in an Excel spreadsheet – rows are which LED to address and columns are units of time. The picture data is then copied and pasted straight from the Excel worksheet to the Arduino source code. This in itself is a pretty clever use of Excel.

Check out the how [Michael] creates one of his light paintings here.

Scavenging Ambient Electromagnetic Energy

July 11, 2011 by 66 Comments

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At this very moment, unseen radio waves are bouncing off almost everything that surrounds you. Emitted by everything from radio and TV stations to cell phone networks and satellites, these waves are full of unharnessed energy. That is, until now. Researchers at the Georgia Tech School of Electrical and Computer Engineering have been working diligently to harness this unused energy, and recently unveiled their new antenna technology at the IEEE Antennas and Propagation Symposium.

The team, led by professor [Manos Tentzeris] has been working to develop ultra-wideband antennas to tap into the energy all around us. Using printers filled with a specially-formulated ink compound, they have been able to print these antennas on paper and polymer substrates. The antennas can harness energy stored in radio frequencies ranging from 100 MHz all the way up to 60 GHz, depending on the printing medium.

The team can currently power temperature sensors using television signals, and is preparing a demo in which they will power a microcontroller simply by holding it up in the air. The technology is still in its infancy, but the list of applications is almost endless. We doubt you’ll be powering your TV with this technology any time soon, but it definitely holds promise for things such as wireless sensor mesh networks and the like.

[Thanks, morganism]

Waterfall Signal Visualizer From Arduino And Cellphone LCD

July 11, 2011 by 12 Comments

[Leigh] is a HAM operator (you may know him as wa5znu). He is familiar with a signal visualization tool called a waterfall which plots signal strength and frequency over time. He wanted to build his own waterfall and ended up with this Arduino-based version which he calls Cascata. Cascata means waterfall in Italian which meshes nicely with Arduino’s country of origin

The display he chose is a Nokia LCD shield from SparkFun. It’s easy to plug in and there were already libraries available to drive the display. The audio input just connects to a headphone plug (you can just make it out at the bottom right in the image above) using some electrical tape. A free-formed resistor divider ensures that the signal is within a measurable range. [Leigh] found that signal noise was a bit of a problem but was able to improve his results by adding a capacitor to the Arduino headers between the VREF and GND pins.

See it in action after the break.

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How To Build Your Own Pulsed Laser Pistol

July 10, 2011 by 50 Comments

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Self-declared Mad Scientist and Instructables user [Trevor Nestor] recently built a pulse laser pistol and decided to share his build process, so that you too can build a ray gun at home. The gun is made up of mostly scavenged components, save for the Neodymium:YAG laser head, which he purchased on eBay for about $100. He does say however, that you can score an SSY-1 laser from an old rangefinder, providing you hang out near a stockpile of decommissioned Abrams tanks.

[Trevor] walks you through the process of recycling old disposable cameras to get enough components for a capacitor bank, as well as how the charging circuit should be constructed. He also discusses how the laser head needs to be wired, before showing off the finished laser pistol in a cheeky video, embedded below.

While the gun lacks the finish of this laser pistol we showed you, it’s no less potent when shooting through plastics, wood, and thin metals. It’s a great starting point if you are looking to build a laser of your own, leaving room for improvements, such as a faster charging circuit.

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Sound Card Microcontroller/PC Communication

July 10, 2011 by 40 Comments

The usual way send data from a microcontroller is either over RS-232 with MAX232 serial ICs, crystals, and a relatively ancient computer, or by bit-banging the USB protocol and worrying about driver issues. Not content with these solutions, [Scott] came up with sound card μC/PC communication that doesn’t require any extra components.

[Scott] bought a cheap USB sound card dongle on eBay (although a built-in sound card will do) and wired up the tip and ring of the plug to the microcontroller. The data is sent from the microcontroller a lot like Morse code – a short gap between pulses is a zero, a long gap is a one. This is parsed by a Python script using PyAudio. Synchronization, timing, and calibration is automatic because of a 10-bit ‘packet header’ explained in this video.

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A Homemade Electric Chair Reveals A Darker Side Of Hacking

July 10, 2011 by 77 Comments

Here is an example of what happens when someone is tempted to use their hacking skills for evil. Hopefully it goes without saying, but do NOT try this one at home.

When his wife asked for a divorce [Andrew Castle] obviously did not like the idea so got busy building himself a DIY electric chair, placing a metal chair in his garage he wired it up to a 240V 13 amp wall output with the intention of luring his wife to sit in the chair for “a chat”. Fortunately the story ends as well as any story involving something as foolish as a homemade electric chair can end. We are guessing that [Andrews] wife’s suspicions were initially aroused when she was invited to sit in the lone metal chair in the garage, whilst he stood behind her holding a rubber cudgel. After a brief struggle she managed to escape unharmed and [Andrew] is now facing 10 years in prison.

All questionable morals aside, from the brief description available it looks like there may have been a few holes in the logic (or lack of) behind the construction of the chair, for one circuit breakers come to mind.

Bubble Blowing Bot Blows Big Bouncy Bubbles

July 10, 2011 by 7 Comments

 

[Rob] Was cleaning out his car hole when he stumbled across a servo, a PC cooling fan, an Arduino and apparently a whole lot of bubble mixture. With all of this, some scrap timber and a few trips to the dollar store, he was able to whip up this bubble blowing bot to entertain his children. It looks like a fairly simple mechanism, the servo tips the old pipe bend into the sudds and the fan provides the air to blow the bubble. The size of the bubble is varied by altering the speed that the pipe bend tips.

The video after the break shows the robot blowing some nice big bubbles, and a quick view of the fan and servo mechanism. There is not a lot of information available but we find the motion of the pipe bend and the big bubbles it blows entertaining, you know the saying, “simple things…”

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