Lighted Fan Pull Saves You From Flailing Around In The Dark

December 9, 2011 by Mike Nathan 25 Comments

lighted-fan-pull

Like many people, [yardleydobon] had a hard time locating his ceiling fan’s pull chain at night when his room is completely dark. Rather than continue to flail around blindly grasping for the chain, he decided to find a way to illuminate it instead.

He started off by disassembling a solar garden light, retaining the solar cell, photoresistor, and batteries. After paring down the electronics to the bare essentials, he mounted them inside a plastic battery storage case which he attached to the outside of the fan’s lamp. [yardleydobon] then ran a pair of wires from the electronics box down to end of the chain, where he added an LED and a translucent pull to diffuse the light.

He admits that it’s not the nicest looking modification around, but it does the job in a pinch. He has some ideas that he may put into play if he has the time to revise the design, and we bet that many of you do as well. If so, be sure to share them in the comments.

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Follow Up: Star Wars Tree Gets An Upgrade

December 9, 2011 by Mike Nathan 2 Comments

We asked, and [Zach] listened.

Earlier this week, we featured a circuit he built which allowed his tiny Star Wars Christmas tree to visually replicate the series’ theme song. Several of you, along with myself, thought it would be far cooler if the tree also played the music to accompany the light show, so [Zach] set off to add that functionality.

Worried that the music would get annoying if it played along with the lights constantly, he tweaked his circuit design to incorporate a piezo buzzer that could be easily switched on and off. After wiring it to the MSP430 driving the light show, he tweaked the program to output signals to both the light string and buzzer simultaneously.

While the light show accurately represented the song, he initially ignored flat and sharp notes as they would be indistinguishable to the eye. In audio form however, the missing notes would be glaringly obvious, so he re-transcribed the sheet music resulting in the video you see below.

If you happened to follow [Zach’s] lead and put one of these together in your own house, be sure to swing by his site and grab the latest code, complete with audio track.

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Color Sensing With An RGB LED And Photoresistor

December 8, 2011 by Mike Szczys 11 Comments

[Fjord Carver] brings together an RGB LED and CdS Photoresistor to make a color sensor. Those Cadmium Sulfide lights sensors usually have a very wide swing of resistance when exposed to varying levels of light sensitivity. That makes for great resolution when reading them using the ADC of a microcontroller. The LED comes into play by shining known wavelengths of light on the surface being measured. Three separate readings are taken with each of the LED’s different colors, then used to extrapolate the RGB value of the test material. We saw the very same method used a couple of years back. This time around it’s an Arduino doing the measuring instead of a PIC.

So why isn’t that sensor shown in this picture? It’s because we appreciate the application which [Fjord] is using for this sensor. He built a lamp that shines the same color as the surface on which it is placed.

The Force Is Strong With This Christmas Tree Light Show

December 5, 2011 by Mike Nathan 6 Comments

[Zach] is a huge Star Wars fan, and in addition to the array holiday decorations that adorn his house, he says that his wife is nice enough to let him put up a Christmas tree full of Star Wars ornaments. For the past few years, the tree sat in the corner of the room unlit, but his wife thought that it should have some lights this year.

His wife came home with a small string of battery-operated lights, but [Zach] wanted something with a bit more geek cred. He decided to program the lights to play the Star Wars theme song, translating the tune’s pitch to light intensity.

He dug through his bin of electronics and found an MSP430 along with a small target board that would do the job nicely. He sat down with some sheet music, translating the notes to PWM values, resulting in the light show you see below.

While his wife provided a lovely violin accompaniment to the tree, we think that a small audio module would make a great addition to the tree next year.

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10 Meter Long Moving Light Show Is Mesmerizing

December 3, 2011 by Mike Nathan 13 Comments

light-show

[Marcus] was recently commissioned to put together the electronics for a slick 10 meter long LED installation at the Hsinchu Biomedical Science Park Exhibition Center in Taiwan. While you might assume that he was asked to construct a large LED matrix, this project is a little bit different from what you probably expected.

The display is actually a long light tunnel made up of 30 moving triangles suspended from the ceiling. The triangle movement is governed by 60 separate stepper motors, while the lighting is provided by 30 HL1606 RGB LED strips he picked up from Adafruit. The display’s logic is handled completely by an XMOS controller, which is beefy enough to handle controlling all of the stepper motors and the LEDs simultaneously.

After he hand assembled all of the motor driver boards and tested things in his workshop, the whole lot was shipped over to Taiwan for assembly by the on-site crew. After a bit of troubleshooting, they were able to get things working properly, and the display looks great as you can see from the image above.

[Marcus] says that he doesn’t have video of the display in action just yet, though he will update his post whenever he does.

[Thanks, Paul]

Trying To Measure The Speed Of Light With An Arduino

December 1, 2011 by Brian Benchoff 63 Comments

We know that measuring the speed of light with an Arduino is possible. It’s just that the implementation is hard.

Last month we saw [Udo]’s blinkenlight shield that can be used as a line scan camera. It’s a neat piece of kit, but [Udo] really wants to submit something for the Buildlounge laser cutter giveaway, so he figured measuring the speed of light would be an easy project. If a kid and a chocolate bar can do it, surely it can’t be too hard.

[Udo] hit upon the idea of pulsing a laser pointer and measuring the time of the reflection. Because his blinkenlight shield can be used as a light sensor, all that’s needed is a mirror and a pretty long line of sight. There’s a few problems with the setup though: with the Arduino running at 16 MHz, a photon will travel 19 meters in one clock cycle.

Even with some very clever coding, we’re not really sure detecting an emitted photon is possible at such (relatively) slow clock speeds. We’re thinking [Udo] could source a few hundred meters of optic fiber so the entire experiment could fit on a desk, but feel free to drop a note in the comments if you’ve got a better idea. [Udo]’s demo of his blinkenlight/laser mashup is after the break.

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Custom Massive LED Panel Lights Up The Party

November 30, 2011 by Mike Nathan 12 Comments

giant-led-sign

The guys at BuildLounge wrote us to share a giant LED sign they came across in the submission pile for their “Win a Laser Cutter” contest that’s currently under way. [Stephen Shaffer] helps run a huge party called Fantastic Planet, for which the group typically outsources the lighting arrangements. They got tired of hiring light guys several times a year and built their own mega display for the festivities instead.

The LED sign consists of 1,474 LEDs that output well over 10,000 lumens. The sign was produced for just about $800, which is very reasonable for a display of its size. The whole thing is controlled by a pair of Arduinos paired with 34 MIC5891 shift registers, all mounted on custom designed PCBs that the group produced in-house.

The display looks great, but don’t take our word for it – check out the video below to see it in action.

If you are interested in taking a closer look at how it was built, swing by the build thread to see more details.

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