Garage Monitor Has An Extra Arduino

December 14, 2010 by Devlin Thyne 57 Comments

[Jody] wanted to know when his garage door was open. He details his setup which uses a temperature sensor read by an Arduino to send over XBee radio to a computer running a Windows Service. We have seen this twice before, and is noteworthy as a lesson. The XBee radios have the ability to read analog data, relay digital signals, and a lot more. This means the Arduino is completely unnecessary. For example, the Tweet-a-Watt uses two of an XBee’s ADCs to measure voltage and current in a Kill-a-Watt power meter. Programming an XBee is really simple, with the help of tutorials from SparkFun and Adafruit. A bit of programming and soldering should get [Jody] back his Arduino. We hope this note will help you find more creative uses of XBees without microcontrollers.

[Via Make]

Thanksgiving Turkey Quadcopter Shenanigans

November 26, 2010 by Mike Szczys 9 Comments

The challenge: can you build a flying turkey that drops pumpkin pie bombs? That’s the question that Utah Aerials asked themselves and they did manage to make it happen. Of course they’re not starting from scratch, but adding a little holiday cheer to an existing quadcopter in the form of a spray painted turkey fuselage. The cheapest pumpkin pie they could find was hung from the copter with care, and dumped thanks to a servo motor. Check the video after the break to see if they were able to hit their balding-bullseye or not.

Seems like the wicked witch music should have been the background for that video.

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Your Mobile Phone, Now With 100% More RFID

November 7, 2010 by James Munns 15 Comments

More and more today, it is becoming harder to avoid having some sort of RFID tag in your wallet. [bunnie], of bunnie:studios decided to ease the clutter (and wireless interference) in his wallet by transplanting the RFID chip from one of his subway cards into his mobile phone. Rather than the tedious and possibly impossible task of yanking out the whole antenna, he instead pulled the antenna of a much more accessible wristband with an RFID chip of similar frequency instead. Nothing too technical in this hack, just a great idea and some steady handiwork. We recommend you try this out on a card you haven’t filled yet, just in case.

Plantenna: The Plant Antenna

October 20, 2010 by Jakob Griffith 37 Comments

The back story behind [Mike] experimenting with plants as AM radio transmission antennas antennae is rather interesting and worth the short read. But for those who just want the facts, [Mike] took an ATMega324, modified the PWM output into a sinusoidal AM signal (using a simple form of RLC circuitry), and connected the circuit to a plant no plants were harmed in the making of this project. The results? Well we’re not ones who would spoil the surprise, you’ll have to see for yourself in the video after the jump.

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Data Confirmation With RF Communications

October 18, 2010 by Mike Szczys 35 Comments

[Rafael] built a system that uses radio frequency for communications. The code he was using with the inexpensive receiver/transmitter pairs already had some error correction but from time to time an entire message would be missed by the receiver. He set out to make these RF communications more robust.

A little more than a year ago we looked at using these same transmitters with an Arduino. [Rafael] has a similar setup but since they are unidirectional he chose to use two pairs for bidirectional communication (each operating at a different frequency to avoid interference). On one end, a computer transmits data to the Arduino which is in a remote location. His confirmation protocol relies on a randomly generated message identifier. The computer will continually transmit the same message. The Arduino continually receives these messages, comparing them with the last successfully received message. If they match, it is considered a successful data transfer and the Arduino transmits a confirmation back to the computer which then starts transmitting the next message.

This isn’t an application-specific protocol. For demonstration purposes [Rafael] built a quick home automation setup that uses it to operate a house lamp.

Pulling Data From The IM-ME Spectrum Analyzer

October 9, 2010 by Mike Szczys 4 Comments

A small, cheap spectrum analyzer with an LCD can be a fun thing to play with. But to be truly usefully you need access to raw data, and lots of it. [Travis Goodspeed] set out to make that possible by pulling data with a GoodFET and a Python script.

He started with [Michael Ossmann’s] IM-ME spectrum analyzer, which uses a CC1110 chip. The two of them are giving a lecture at Toorcon 12 (called Real Men Carry Pink Pagers) and this will be used as a demonstration device. After studying the datasheet he found the starting RAM address and did some further work to deciphered how the data is stored in it. From there it was a matter of working out the timing for grabbing the data, and coding a method for storing it. Now he’s looking for brave souls to help him trailblaze with this newly-discovered tool. It seems that if you know what you are doing, and have abundant patience, you can use this for a bit of old-fashioned reverse engineering.

An Interesting Take On WEP Cracking

October 7, 2010 by Mike Szczys 19 Comments

[Ben Kurtz] is doing a little WEP cracking but in a bit of a different way than we’re used to. WEP cracking makes us think of war driving; driving around with your laptop open, looking for WiFi access points, and stopping to run some software when you find them. [Ben’s] way is similar but different in one key way, he’s using an iPhone as the frontend.

This started as a way to find a use for some leftover equipment. He threw together a Linux box and loaded up Aircrack-ng, the software we often see used in penetration testing. To remove himself from shady-looking activities in public he coded a web interface using the Python package Turbogears. It uses screen, a program often used with SSH to run services concurrently in different terminals, with the option to disconnect without stopping the processes. Now it’s just a matter of parking the hardware near an AP, and doing the work in a browser on your mobile device. You can check out the script he wrote, as well as installation instructions, in his post linked above.

[Thanks Tech B.]

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