Reverse Engineering Radio Controlled Outlets

January 26, 2011 by 31 Comments

[Chr] picked up a pack of remote control outlets in order to reverse engineer them and build control into his own projects. These can be plugged into outlets around your house and a relay inside each module will switch whatever device is plugged into it after receiving a command from the remote. Once he cracked open the control housing it was easy to find the data line for the RF module which was on its own board. He used a logic analyzer to capture data from various button presses and then spent some time deciphering the communication protocol. He used what he learned to roll the module and code into an interface box where an ATmega8 connects via USB and passes commands from a computer to the RF board. Now he’s added home automation via a computer quite inexpensively. After the break you can watch a clip of the outlets switched using a smartphone.

So why not just patch into the buttons on the remote? Well, this same project was attempted at our local hackerspace earlier this month and the buttons don’t just pull a pin to ground. They use tri-state logic and are arranged into a matrix that is a lot harder to mimic (if not impossible) with a microcontroller. Analyzing the communications going into the RF module is definitely the less labor-intensive of the two approaches.

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12 Foot LED Display Keeps Your Office Informed

January 26, 2011 by 20 Comments

Don’t reach for a sticky note when you need to leave a message for your office mates, write it down on a 12 foot LED marquee. [Kitesurfer1404] built this for his home office, but we’re sure he’ll find fun stuff to use it for. The display has 512 LEDs driven by plain old 595 shift registers for the high-side columns, with an ULN2803A Darlington Array to pull the eight rows to ground. The whole thing is controlled by an ATmega8 via a serial connection. Our compliments to the builder for accurately drilling a grid of 64×8 holes in each hardboard panel of the display. The buses for each row and column also look nice and clean. For the final look a 79% light transmittance frosted acrylic panel was added to diffuse the light.

We used the same method to build our LED pumpkin. Transistors ran the low side, and if we had needed more columns, shift registers are a popular go-to for I/O expansion. Check out that project to learn more about display multiplexing.

ROS Gains Full Body Telemetry

January 26, 2011 by 28 Comments

[Taylor Veldrop] has been playing with an NAO robot and ROS, mixed with a Kinect to get some pretty amazing results. The last time we saw any work done with ROS and the Kinect, it was allowing some basic telemetry using the PR2. [Tyler] has taken this a step further allowing for full body control of the NAO robot. Basic mimicking mixed with a little bit of autonomy allow the NAO to follow his steps around a room and even slice a bananna, or hammer nails. We think this is pretty impressive, especially if he were to mix it together with a motion tracking stereoscopic display. Follow along after the break to see it pull off some of these cool feats.

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Abusing HTTP Status Codes

January 25, 2011 by 25 Comments

Concerns over privacy online are an ever growing theme. Every day we see people complaining about the policies of facebook and the like. [Mike Cardwell] points out another method of gleaning a bit of personal data from you that you may not have seen yet. By embedding a hidden image or using some really simple javascript, he can tell if you are currently logged into Gmail, Twitter, Facebook, or Digg. While this could possibly be used for more nefarious things, he points out that you could also use it for customizing your website to better suit the experience of the browser. For example, if the “reader” is already logged into Gmail, you could have any email links automatically open a gmail instance instead of the local mail client.

Wireless Sniffing And Jamming Of Chronos And Iclicker

January 25, 2011 by 1 Comment

The ubiquitous presence of wireless devices combined with easy access to powerful RF development platforms makes the everyday world around us a wireless hacker’s playground. Yesterday [Travis Goodspeed] posted an article showing how goodfet.cc can be used to sniff wireless traffic and also to jam a given frequency. We’ve previously covered the work of [Travis] in pulling raw data from the IM-ME spectrum analyzer, which also uses goodfet.cc.

The Texas Instruments Chronos watch dev platform contains a C1110 chip, which among other things can provide accelerometer data from the watch to an interested sniffer. The i>clicker classroom response device (which houses a XE1203F chip) is also wide open to this, yielding juicy info about your classmates’ voting behaviour. There is still some work to be done to improve goodfet.cc, and [Travis] pays in beer–not in advance, mind you.

With products like the Chronos representing a move towards personal-area wireless networks, this sort of security hole might eventually have implications to individual privacy of, for example, biometric data–although how that might be exploited is another topic. Related to this idea is that of sniffable RFID card data. How does the increasing adoption of short-range wireless technologies affects us, both for good and bad? We invite you to share your ideas in the comments.

Inaccurate Breathalyzer Is Still Quite Nice

January 25, 2011 by 14 Comments

Sure, [Hunter Scott’s] Breathalyzer can only differentiate between hammer and sober, but look how nice it came out. He’s using an MQ-3 alcohol sensor which, from previous projects, we know is very difficult to accurately calibrate. But if you want to monkey around with embedded systems you’ve got to have a goal. [Hunter] chose a gorgeous aluminum project enclosure, adding a big LCD display to the to the lit. The switch on the bottom selects between on, off, and charging modes. He’s using a USB charger from Adafruit to top off the lithium battery inside. Everything runs on 3.3V with the exception of the sensor which gets its 5V supply from a boost converter. An Arduino is the brains that pulls everything together.

See [Hunter’s] video description of the project embedded after the break.

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Monocrome To Magnificent: Computer Display Chronology

January 25, 2011 by 45 Comments

Remember when CGA came out and made monocrome monitors look horrible? Well CGA is crap, VGA is where it’s at. Wait… weren’t there a couple of standards in between those two? Take a walk down memory lane and relive the evolution of computer display technology. You’ll start with displays that are more or less CRT oscilloscopes and end up in better than high-def territory. The article is an interesting read but for those with short attention spans jump to the fourth page and check out the chart of technologies, resolutions, and implementation dates. We’ve come a long way in a few short decades.