Retrotechtacular: History of the U.S. Antiballistic Missile Systems


On this installment of Retrotechtacular we’re taking a look at the history of the United States Antiballistic Missile System. The cold war was a huge driver of technological development, and this missile defense is a good example. At its most basic this is a radar system capable of tracking objects in three dimensions. It utilizes separate transmitters and receivers which are synchronized to rotate at the same time.

The movie, which is about forty-five minutes, came to our attention because of [Dammitd's] interest in the Luneburg Lens used by the system. At about 11:10 into the video after the break this component is discussed. Inside a dome like the one seen above is a reflector made of blocks of polystyrene foam which has been laced with bits of metal. This lens is stationary, with the receiver rotating around it to collect the transmitter’s waves as the echos bouncing off an object in the sky are focused by the lens.

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Sump pump alarm sends text message as water rises


We’ve got some friends who have two sump pumps. One is a backup and sounds an alarm when it is switched on. But this only works as long as they’re home to hear it. [Felix Rusu] came up with a solution what will text him if the sump pump fails. This way he can head home, or call someone to check in on the problem if he’s away.

We saw a pretty complicated monitoring system back in January. This one uses a single ultrasonic rangefinder which we think is much simpler. It’s accurate to about 1cm and is simple to use — it’s very popular with the hobby electronics crowd which helps with price and availability of sample code. We hem and haw about the use of a Raspberry Pi board with the project. On the one hand it’s a cheap way to get the sensor on the network and provides the infrastructure you need to send any number of alerts. On the other hand, it’s a lot of power for this particular application. But we figure it can be extended to monitor other utilities in [Felix's] home, like a sensor to alert him of a leaking water heater. And we think everyone can argue that a monitor like this is well worth the time and effort he spent to develop it.

Scratch-built 3D printer shows rock-solid performance


These days it’s super-easy (not super-cheap) to go out and buy a 3D printer. But if you’ve got the mad skills like [Mario Lukas] maybe you can build a 3D print using a bunch of scavenged parts (translated). He’s published six posts on the build, and put together an overview video which you can watch after the break.

A pile of salvaged parts were found in a scanner and four different printers. He’s also powering the thing with an old PC PSU. The hot bed and extruder are brand new, which is a wise investment. We’re not sure about the threaded rod and bearings but we’d bet those are new as well. When it came time to work on the electronics he chose an Arduino board as the go-between for the printer and computer. It uses four stepper motor driver boards to drive the axes. Connections can be a bit complicated and he actually ‘smoked’ one of the boards during the development phase.

One of the mechanical build posts shows a belt routed in a T-shape. We wonder if it’s function is similar to what this H-bot style printer uses?

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Sega controller houses auto-launch emulator


[Joe's] wife grew up playing Sega games and he wanted to help her unwind by reliving the experience. Since the work computer she uses when travelling isn’t a good place to install emulators he built this plug-and-play emulator inside of a Sega controller.

We’ve seen this type of thing a few times before (even with XBMC in a SNES controller) but there is one thing we hadn’t thought of lately. Newer versions of Windows have auto-launch disabled for USB drives. But [Joe] knew that there were still some USB sticks that manage to auto-launch anyway so he researched how those work. It turns out that they have two partitions, one is formatted as a CDFS which looks like a CD-ROM to Windows and allows auto-launch. He used this method of partitioning a USB stick, storing the ROMs on the mass storage partition and the emulator and the CDFS partition. To finish the hack he cracked open the controller and found room for a USB hub and the PCB from the thumb drive.

If you still have cartridges lying around you can pull the ROMs off of them over USB.

Wifi Pineapple project uses updated hardware for man-in-the-middle attacks


We’ve seen this small, cheap, and powerful WiFi router before. But this time it’s up to no good. [Andy] used a TP-Link WR703N to build an upgraded WiFi Pineapple hacking tool.

A WiFi Pineapple is a device spawned years ago by the Hak5 team (here’s a clip showing off the device). It uses a WiFi router that will answer to any SSID request. Basically if your computer or smart phone has an AP SSID saved and broadcasts a request to connect the pineapple will pretend to be that device and start the handshake. This provides the chance to sniff all the data passing through in a classic man-in-the-middle attack.

[Andy] is recreating the device but at a rock bottom price. He picked up this router for about $20 and added an $8 USB drive to it. The only other thing you would need is a power source and a way to hide the hardware. The code used in the Hak5 version is available for download and that’s what he worked on after flashing OpenWrt to the device.

[Thanks Midnite]

Chromebook hack controls your television


[Michael Kohn] only accomplished about half of what he set out to, but we still think his TV channel switcher from a Chromebook turned out nicely. When starting the project he wanted to include a grid of listing so that he could choose a specific program, but decided that scraping the data was too much work for this go-round.

The Chromebook doesn’t include an IR transmitter so he built one using an MSP430 chip. He had previously built a little transmitter around an AVR chip and was surprised to find that the internal oscillator on that was quite a bit more accurate than on the MSP430. Timing is everything with the Manchester encoded signals used for IR remote controls so he used his oscilloscope to tune the DCO as accurately as possible.

The app shown on the screen was written in Javascript. Google published some example code on using RS232 with the computer; [Michael] used this resource to provide communications between the computer and the microcontroller.

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Hackaday Links: Sunday, April 28th, 2013


Another week has gone by and we hope you’ve been happily hacking away in your underground lairs. If not, here’s some inspiration that didn’t quite make it to the front page this week:

[Razr] used a CFL ballast to replace the mechanical one in his fluorescent tube light fixture.

To make the drawers of his workbench more awesome [Rhys] used the faceplates from some servers.

This week saw some changes in the hobby PCB market. Looks like BatchPCB is being sold to OSH Park starting May 1st. [Thanks Brad]

[Rich Olson] shouldn’t have any trouble getting out of bed now that his alarm clock literally shreds cash if he doesn’t shut it off.

We faced the same problem as [Kremmel] when we first got a Raspberry Pi, no USB keyboard. We bought one but he simply hacked his laptop to work. [Thanks Roth]

You may remember that post about a self-propelled snowboard. Here’s a similar project that uses a screw-drive system.

And finally, if you need help reading a quadrature encoder from a microcontroller this lengthy technical post is the place to look.