Month: April 2012

Electronic Table Top Catapult

April 30, 2012 by 14 Comments

[Unusualtravis] came up with this fairly slick electronic catapult. This easy to construct and moderately cheap rig has an arduino as the brains and controls for 3 servos. One is the release, another controls tension, and the third controls the angle. Both the circuit and the construction are very simple making this a perfect weekend project. He would have preferred it to be a bit smaller, so shoot him your design if you manage to shrink it.

We’ve always been rather fond of catapults of whatever complexity, so feel free to send in any variations you’ve worked on.

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6 Camera Face Scanning Rig

April 30, 2012 by 6 Comments

[Ajeromin] was asked to build something cool for a museum exhibit. He took the challenge, and with his facial capture device, we feel he delivered. The writeup is very short, most of the story is in the annotated images. After deciding he was going to do facial capture and convert it to 3d, he had to start planning. There are many ways to do this, but usually the person having their face captured isn’t an excited child at a museum. The presented some unique challenges in that he knew he would have to capture all the images at once, and quickly too. To do this, he lit the entire rig very well to reduce the amount of noise in the pictures and wired all 6 cameras up to snap at the same moment. He even encapsulated the circuit in a glass jar just so the kids could see more of the parts.

The next logical step would be to attach this to a 3d printer and let people buy 3d printed models of their face. The quality is certainly good enough as he shows in one of the final images.

Great job [Ajeromin]

 

Tindie: An Etsy For Electronics

April 30, 2012 by 39 Comments

If you have a finished project you’re now bored with, here’s Tindie. It’s a one-man operation headed b [emile] that hopes to connect makers with people who think DIY projects are really cool and have money.

There are already a few websites that cater to the builder who wants to sell projects: Kickstarter for one, but this is based on the concept of campaigns. Tindie aims to be a techie etsy, according to [emile]’s market research post on reddit;  a places for makers with a soldering iron to sell stuff, but who are baffled by the concept of knitting.

Right now there’s nothing to buy on Tindie – [emile] is looking for hackers to sell their projects so the store doesn’t launch with an empty stockroom. If you’ve got an old project sitting on your shelf that you’d like to sell, put it up. [emile] is only taking 5% of the sales – just enough to pay for the hosting. Hopefully it will be popular enough for the eventual Tindie/regretsy blog.

Quick And Easy Wildlife Camera

April 30, 2012 by 9 Comments

This wildlife camera is really easy to put together. You should keep it in mind if you’re ever tying to figure out what’s eating the heads off of all of your tulips. [Revoltlab] put it together, and although there’s one fatal flaw in this particular system, the concept is quite sound.

The build uses a camera, paired with an ultrasonic range finder. When something passes within the pre-set distance for the sensor, a servo motor clicks the shutter button on the camera. It’s all driven by an Arduino and powered from a 9V battery.

If you watch the video after the break you’ll discover the flaw we mentioned. This is a disposable film camera and requires winding between pictures. That hasn’t been implemented yet. But we’ve got an old digital camera with a broken LCD screen which would be perfect for the job. We’d have to do a bit more work to turn the camera on before taking the picture though.

There are a couple of possible upgrades to the idea. [Revoltlab] mentions removing the IR filter from the camera and adding an infrared flash for night-vision shots. But we would also recommend ditching the servo motor for a simple remote shutter solution as a way to avoid scaring the wildlife with the motor noise.

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Inconspicuous Guitar Hack Adds A Lot Of Control To Max/MSP

April 30, 2012 by 4 Comments

[Sam] is working on his Interactive Technology Degree and he made some alterations to this guitar as a class project. It doesn’t look much different, but closer inspection will reveal a handful of extra buttons, and a camera module. He actually added a Wii remote to the guitar which is used to control Max/MSP.

His pinky is pointing at one of the buttons. That one is red and triggers the Bluetooth sync function for the Wii remote. The other four buttons are wired to the up, down, A, and B buttons. In the video after the break [Sam] talks about the Max/MSP front-end which is used to connect the remote to the computer. Once communications are established the accelerometer sensor data is continuously streamed to the software, and the other four buttons are used for controlling the patches.

The camera module that is mounted in the guitar can be used to stream video but it appears to have no effect on the sound. In fact, the live video feed can be mixed with a waveform generation. Sound characteristics like volume affect the cross-fade between the two video signals. [Sam] talks about this feature, but when the playing demo starts about 6:10 into the clip we don’t seen any of the live video on the projection screen.

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Signal Sniffing Some Laundry Pay Cards

April 30, 2012 by 19 Comments

It seems that [Limpkin] was up to no good this weekend. He decided to snoop around inside a smart-card laundry machine. He posted about his larceny  adventure and shared the details about how card security works with this machine.

We’re shocked that the control hardware is not under lock and key. Two screws are all that secures the panel to which this PCB is mounted. We know that machines using coins have a key lock, but perhaps there isn’t much need for that if there’s no currency to steal. [Limpkin] made a pass-through connector for the ribbon cable coming in from the card reader. That’s the rainbow cable you can see above and it’s being fed to his logic sniffer. He used the ‘card detect’ signal as a trigger and captured enough data to take back to his lair for analysis. Using what he found and a Bus Pirate to test the smart card he laid bare all the data that’s being sent and received by the controller.

LED Clock Lights Up A Dead Mac Mini

April 30, 2012 by 6 Comments

[Professor Shadoko’s] Mac Mini died. But since the case designs on Apple products are half the reason to buy them, he decided to reuse the enclosure by turning it into this clock (translated).

As with the binary clock we saw yesterday, this one uses a bunch of LEDs to display the time, but it does it in a way that’s a bit more readable if you know what you’re looking for. The face has been divided up into two columns. On the left is hours, then minutes and seconds in increments of five. To the right is AM/PM, with minutes and seconds in increments of one. If we’re doing this right, the time seen above is 10:23:42 PM on April 28th, 2012. The white LEDs below the date act as a digital pendulum, scrolling left and right as the seconds tick by.

The display uses two MAX7219 LED drivers to control the grid which is build on a big hunk of protoboard. An Arduino ties the whole system together with a Chonodot for accurate time keeping. There’s even an ambient light sensor which adjusts the LED intensity to make this readable in direct sun, or the dark of night. See a demo clip embedded after the break.

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