3D Mapping Of Rooms, Again

June 8, 2013 by Brian Benchoff 19 Comments

Last year we saw what may be the coolest application of a Kinect ever. It was called Kintinuous, and it’s back again, this time as Kintinuous 2.0, with new and improved features.

When we first learned of Kintinuous, we were blown away. The ability for a computer with a Kinect to map large-scale areas has applications as diverse as Google Street View, creating custom Counter-Strike maps, to archeological excavations. There was one problem with the Kintinuous 1.0, though: scanning a loop would create a disjointed map, where the beginning and end of a loop would be in a different place.

In the video for Kintinuous 2.0, you can see a huge scan over 300 meters in length with two loops automatically stitched back into a continuous scan. An amazing feat, especially considering the computer is processing seven million vertices in just a few seconds.

Unfortunately, it doesn’t look like there will be an official distribution of Kintinuous 2.0 anytime soon. The paper for this Kintinuous is still under review, and there are ‘issues’ surrounding the software that don’t allow an answer to the if and when question of release. Once the paper is out, though, anyone is free to reimplement it, and we’ll gladly leave that as an open challenge to our readers.

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USB Infrared Receiver Looks Good Sitting In Your Livingroom

June 8, 2013 by Mike Szczys 7 Comments

usb-ir-receiver

The problem with building your own electronics for the living room is that the final product may not fit your decorating style. This was true with [Itay’s] prototype of a universal USB IR receiver. So after testing it out for a few weeks he decided to build a final version that started by selecting an enclosure he could be proud of.

He came across an LED flash light at the dollar store which has an aluminum body. When we read about this we envisioned a cheap version of a Mag Light from which he removed the cylinder that holds the batteries. But actually, the pod seen above is the entire flashlight (with an added base). It forced him to design a tiny surface mount PCB to fit everything inside.

It’s not too much of a stretch since IR receivers tend to be small anyway. [Itay’s] design put a PIC 18F2553 on one side of the board. The other side hosted the through hole components: an IR receiver, LED for feedback, and the connections for the USB cable that exit through the rubber button cover that used to switch the flashlight on. He had a problem with one of the resistor values which took a while to figure out. But eventually he got it working. It’s been in use now for six months.

No Space In The Garage? Build A Lamborghini In The Basement

June 8, 2013 by Brian Benchoff 5 Comments

It took 17 years, but [Ken Imhoff] finally got the car of his dreams. This isn’t a, ‘go down to the dealership’ situation. No, [Ken] built a Lamborghini Countach by himself in his basement.

The build process started off by fabricating a wooden frame to which hand-crafted aluminum panels were attached. The frame of the car was welded out of tubular steel, and slowly, over the course of 17 years, a custom Lamborghini Countach took shape.

When the car was complete, there was one problem left to solve – how do you get a car out of a basement? Rent a backhoe and knock out a wall, of course. Replacing a few cinder blocks in a properly reinforced wall is a lot easier than cutting a Lambo chassis in half, it seems.

It’s an amazing piece of artistry that is a testament to [Ken]’s skill in metalworking, welding, and pretty much any other skill we can think of.

IOS Keyboard Exploit Allows Brute Force IPad Lock Screen Attack

June 7, 2013 by Mike Szczys 19 Comments

It’s quite common to have a timed lockout after entering several bad passwords. This simple form of security makes automated brute force attacks unfeasible by ballooning the time it would take to try every possible permutation. The lock screen on iOS devices like iPad and iPhone have this built in. Enter your code incorrectly several times and the system will make you wait 1, 5, 15, and 60 minutes between entries as you keep inputting the wrong code. But there is an exploit that gets around this. [Pierre Dandumont] is showing off his hardware-based iPad lock screen attack in the image above.

He was inspired to try this out after reading about some Mac EFI attacks using the Teensy 3. That approach used the microcontroller to spoof a keyboard to try every PIN combination possible. By using the camera kit for iPad [Pierre] was able to do the same. This technique lets you connect wired keyboards to the iPad, but apparently not the iPhone. A bluetooth keyboard can also be used. These external keyboards get around the timing lockout associated with the virtual lockscreen keyboard.

We’re of the opinion that this is indeed a security vulnerability. If you forget your passcode you can simply restore the device to remove it. That wipes all of your personal data which can then be loaded from an iTunes backup. Lockscreens are paramount if a device is stolen. They will give you the time you need to change any online credentials which might be remembered by the device.

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Smoothing PLA Printed Parts

June 7, 2013 by Brian Benchoff 40 Comments

We’ve seen a few advances in the finishing processes of 3D prints over the last few months that result in some very attractive parts that look like they were injection molded. Smoothing ABS prints is now a necessary skill for anyone looking to produce professional parts, but those of us using PLA for our RepRaps have been left in the cold. After some experimentation, the guys over at protoparadigm have come up with a way to smooth out those PLA prints, using the same technique and a chemical that’s just as safe as acetone.

Instead of acetone, the guys at protoparadigm are using tetrahydrofuran, or THF, as a solvent for PLA. Other PLA solvents aren’t friendly to living organisms or are somewhat hard to obtain. THF has neither of these qualities; you still need to use it in a well ventilated area with nitrile gloves, but the same precautions when using acetone or MEK still apply. It’s also easy to obtain, as well: you can grab some on Amazon, even.

The process for smoothing PLA prints with THF is the same as smoothing ABS prints with acetone. Just suspend the print in a glass container, pour in a tiny amount of the solvent, and (gently) heat it. The evaporated solvent will smooth all the ridges out of the print, leaving a shiny and smooth surface. You can, of course, hand polish it by dedicating a lint-free cloth and a pair of gloves to the task.

Apple MagSafe Protocol Hacking

June 7, 2013 by Mike Szczys 4 Comments

[Ken Shirriff] was interested in how the Apple MagSafe works. Specifically he wanted to know what controlled the LED on the connector itself so he tore one open to see what is inside. There’s a chip present and he didn’t waste time figuring out how the MagSafe communication protocol works.

The DS2413 chip he found on the MagSafe’s tiny little PCB has just six pins. Two of these control a pair of LEDs, which give the indicator its color range. Another pin is used for 1-wire communications. When polled the charger will return a 64-bit identification number that includes a variety of information. [Ken] looks into what data is offered from several different models of charger by using the Arduino setup above. But the results are not entirely straight-forward as he discusses in his article. The 1-wire protocol is also used to switch the LEDs. This process is the responsibility of the computer being charged, but [Ken] shows how the colors can be cycled using an Arduino (with a couple of 9-volts as a source instead of a connection to mains).