Aspire One External Antenna

August 23, 2009 by Jakob Griffith 15 Comments

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External antennas on netbooks are notorious, from EEE PCs to the Panasonic CF-R1, but this is the first on an Acer Aspire One we’ve seen. [xRazorwirex] sent in his external antenna hack for the 802.11n capable D150, with the intention of increasing performance, but he says he can’t attest to any change. Unfortunately the lock slot had to be removed, but a small price to pay for a big increase in connectivity. The process seems simple enough, and could probably be done within a half an hour. Now that there is an external link why not build a Cantenna, hop in the car, and HeatMap the neighborhood!

Tunneling IP Traffic Over ICMP

August 21, 2009 by Matt Schulz 21 Comments

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We all hate it when we find an unencrypted WiFi network at our favorite coffee shop, restaurant, airport, or other venue, only to discover that there are traffic restrictions. Most limited networks allow HTTP and HTTPS traffic only, or so is the common misconception. In the majority of cases, ICMP traffic is also allowed, permitting the users to ping websites and IP addresses. You may be asking, “Ok, so why does that matter?” Well, all of your IP traffic can be piped through an ICMP tunnel, disguising all your surfing as simple ping packets. [Thomer] has a detailed guide on how to create and utilize such a tunnel using ICMPTX. So the next time you are at the local cafe and want to fire up VLC to watch TV shows from your home PC, give this guide a quick read.

WiFi Spectrum Analyzer

August 18, 2009 by Caleb Kraft 18 Comments

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[Tim] noticed a 2.4Ghz WiFi spectrum analyzer on thinkgeek a while ago and got curious. He knew that the spectrum analyzers with which he was familiar were giant expensive units, so he got curious what this little dongle was. It turns out, it really wasn’t much at all. Just a simple wireless receiver. He decided that rather than spending the $399 for one, he would toss one together using an Xbee. His total cost ended up at roughly $50 for basically the same unit. While he doesn’t give a schematic, you can download his source code on the site.

Droplet

August 7, 2009 by Caleb Kraft 16 Comments

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[Andrew Rapp] sent in this project called Droplet. He’s been doing work with Xbees and Arduinos together and built this little toy. He describes it as “sort of like a Chumby”. It has built in services for Twitter, Google Calendar, News, Gmail, etc. You can download the full source code and plans on his site. His next planned revisions include possibly running it from a sheevaplug, making a nice case for it, and utilizing the unused pins of the arduino.

BPSK On 433 MHz European ISM Band

August 3, 2009 by Steve Watkins 10 Comments

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[WaveRider] is using a type of phase shift keying called BPSK to transmit digital sound and video for remote telemetry. Though a higher signal to noise ratio (SNR) is generally sought after with communications, legal limitations are imposed on total radiated power. To balance the two headed beast, he opted out on frequency shift keying due to binary shift keying’s ability to work with lower SNR. This adds the difficulty of properly reconstructing the digital signal at the receiver. A PLL based carrier regeneration circuit is used to reconstruct the signal. Using the Rabit2000 processor as the host controller on both transmitter and receiver, 96KB/Sec serial data is obtained. On the other side of the spectrum is the Homemade regenerative tube radio.

Homemade Regenerative Tube Radio

July 13, 2009 by Steve Watkins 24 Comments

There are no microcontrollers in this project. In fact you wont find a single transistor. This classic regenerative tube radio, modeled after an early 20th century homebrew is complete with schematic and additional photos. For those who are not familiar with tube designs and for simplicity, the regeneration circuit can be thought of as feedback though this relation may be argued. Read the rest after the break which includes a crash course in tube operation. Continue reading “Homemade Regenerative Tube Radio” →

Various Cantenna Builds

July 7, 2009 by Steve Watkins 27 Comments

Here is a classic project used to increase wireless signal strength. Cantennas focus using a waveguide very much like a magnifying glass focuses light. [Robert] made a Natural Light beer cantenna, pictured in the upper left. His approach used three beer cans, a paper towel holder, and a shower curtain rod. On the tipline, he noted a signal boost from 11Mbps to 54Mbps. This is certainly something we can hack together if our room lacks adequate signal. Read about parabolic and seeking versions after the break.

Continue reading “Various Cantenna Builds” →