Circuit Playground – An Electronics Reference App From Adafruit

February 7, 2012 by Mike Nathan 36 Comments

It’s not everyday that we review software around here, but the folks at Adafruit recently put together an iOS app that I figured might be of interest. Their iPad/iPhone compatible application is called “Circuit Playground”, and it includes all sorts of handy electronics reference tools. For the context of this review, it should be noted that I paid for the application myself, and that I have had no communication with the Adafruit team regarding my assessment of the app.

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Tweets Send Your Balls Flying (on TV)

February 7, 2012 by Mike Szczys 7 Comments

Members from the London Hackerspace recently got a little on-air time with a ping pong ball launcher. They were invited to build something for the Click show on BBC. The launcher that they built responds to hash tags on Twitter by barraging the audience with balls.

The hardware was built in two parts. The first is a dispenser that responds to incoming Tweets by releasing one ball onto a set of staging ramps. The other portion is the launcher itself. Building it like this makes it a rapid fire device, as the spinning wheels of the launcher make quick work of several dozen balls just waiting to be let loose. Check out some footage from the show after the jump.

We like this one just as much as that remote controlled launcher. We’re glad to have seen these both because we happen to have a surplus of the balls lying around since we built that clock and we’re not about to undertake some of the more dangerous ping pong based projects we’ve seen. Continue reading “Tweets Send Your Balls Flying (on TV)” →

Color Sensor Gives The RGB Values Of Anything

February 7, 2012 by Brian Benchoff 28 Comments

[Rick Osgood] wanted to build a color sensor that could be held up to any object to get RGB color values. He originally started with a photoresistor and a few LEDs, but couldn’t get that to work reliably. [Rick] finally completed his color sensor after finding a digital luminosity sensor on Adafruit, ending up with a pretty accurate piece of hardware to judge the color of something.

The idea behind the color sensor is to light up red, green, and blue LEDs and see how much light is reflected back from the object with a luminosity sensor. [Rick] chose an Arduino to do all the heavy lifting for the light sensor and activating the LEDs.

After a few tests [Rick] got his color sensor working, but it’s not up to par with what he had expected. This isn’t really a problem: the LEDs probably don’t have the same brightness and the luminosity sensor doesn’t respond evenly across the entire rainbow. Those things can always be fixed in software, though. It’s a nice project that could serve as part of a prototype for this color picker pen.

Beer Mini-kegs Turned Into A Cyclonic Dust Collector

February 7, 2012 by Mike Szczys 19 Comments

[Darrell] made his own cyclonic dust separator which connects to a shop vac. We’re amused by his poke at Dyson’s marketing machine where he mentions that the ads say it took years to perfect those vacuum cleaners and he managed to put his together in a few hours…. from trash/recyclables no less!

Two mini-kegs are used as the separating vessel. The only other parts are some PVC plumbing fittings which help to direct the air and give him a way to attach the collector to the shop vac. The top keg is where all of the magic happens. Air and debris is sucked in through the hose coming in the side wall. A 45 degree elbow directs it downward and to the side, which starts the cyclonic action. The shop vac is attached to the tube in the top, with a cylinder extending into the keg. The spinning air must make a sharp turn to get into that cylinder; it’s at this point the debris drops out into the lower keg. See for yourself in the clip after the break.

This isn’t the first time we’ve seen dust collectors that use this concept. [Darrell] pointed out this one made out of plastic cups, and this other made from a 5-gallon bucket.

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Building LED Walls On The Cheap

February 6, 2012 by Brian Benchoff 7 Comments

Around this time last year, [KopfKopfKopfAffe] was enlisted as a set designer and was told to build some sort of light effects for electronic music parties. The budget for the project wasn’t much at 200 Euros, but he did manage to build decent 5×5 RGB LED matrix that is fully controllable by a computer.

[KopfKopfKopfAffe] didn’t have the time or money to wait for manufactured PCBs, so a bunch of perfboard was placed in a CNC mill with a pen to act as a plotter. All the lines that needed soldered were drawn on by the mill, a feat that probably saved hours of looking at the design before committing solder to iron.

A total of five boards were constructed, each one capable of controlling five RGB LEDs. Each board can be dasiy-chained with an RS-232 serial connection for further expansion. The only thing that’s needed to control the matrix is 17 bits that includes an address and RGB color data for each LED. The system only cost about 10 Euros per node, but we think that could be significantly reduced by leaving out the Molex and DB-9 connectors. [Kopf] project turned out very nice, check it out after the break.

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Play Hide-and-go-seek With Infrared LEDs

February 6, 2012 by Brian Benchoff 16 Comments

Although we’re sure they exist, we wouldn’t want to meet anybody that can’t look back fondly on the halcyon days of youth that included playing hide-and-go-seek. Some kids never grow up and continue the tradition with geocaching or orienteering, but that sense of limitless discovery wanes over time. [Kurt] came up with a small scavenger hunt beacon that brings back the unending wonder that accompanies the unknown.

The beacon is just a simple ATtiny13 that flashes a message with an invisible IR LED. To receive the messages, [Kurt] made a scavenger decoder shield for an Arduino. The decoder includes a phototransistor and a 20×4 LCD display. All [Kurt] needs to do is hold the decoder up to the beacon for the text in the firmware of the ATtiny to be displayed. The beacon is only one inch square and powered by a watch battery, so it can be hidden anywhere.

[Kurt] suggests that the text of one beacon should provide the clue to the next. We’re thinking this is just a great excuse for a walk in the park. You can check out [Kurt]’s IR decoder getting data from a beacon after the break.

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Replacing A Phantom Limb With A Kinect

February 6, 2012 by Brian Benchoff 6 Comments

Nearly everyone has heard of phantom limb syndrome. It occurs sometimes after a limb is amputated, but the mind of the patient still thinks that the limb is attached. Generally regarded as a mix-up in the wiring of the damaged nerves, a phantom limb can be very painful. [Ben] has been working on a way to alleviate some of the pain and frustration associated with a phantom limb and fortunately for us he went for a Kinect, VR goggles, and gyroscope build.

Today, most therapies for phantom limb syndrome use a Ramachandran Mirror Box. The theory behind the mirror box is pretty simple – if someone recently lost a hand, just insert one hand in one side of the box and the arm stump on the other side. Looking into the box from the side with the good hand will trick the patient’s brain into thinking the amputated hand is still there. It’s a good therapy that has been very successful, but [Ben] thought he could do something that is a little more immersive.

[Ben]’s project uses a Kinect and VR goggles to put the patient in a virtual environment. With the help of a few gyroscopes, the patient gets a virtual representation of their whole self projected into their goggles. The technique isn’t terribly different from VR phobia treatment, although there’s much more electronics and math involved in [Ben]’s build. The first test subject said his pain was going down, so it looks like he might have a success on his hand (no pun intended).

Check out the demos of [Ben]’s treatment plan after the break.

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