Cheap Wireless For Microcontrollers

August 30, 2009 by Jakob Griffith 44 Comments

hr_RF_circuit

Everybody loves microcontrollers, including the Arduino, allowing you to create whatever you imagine. That is unless you want to hack together something wireless. Originally you had to rely on the expensive XBee protocol or other wireless options, but no longer. Hobby Robotics found an extremely cheap transmitter and receiver and wrote a quick guide for wiring them up to an Arduino. Now your wireless projects can come to life, as long as you are within 500 feet and don’t mind 2400bps; minor trade offs compared to the gains of wireless freedom. Final note: You aren’t limited to Arduino, we would love to see someone modify this to work with a PIC or other microcontroller.

Wireless Electricity

August 28, 2009 by Mike Szczys 78 Comments

[ted id=619]

[Eric Giler] has a talk available over at TED that discusses and demos delivering electricity without wires. Called WiTricity, these methods were developed by a team at MIT a few years ago who were working off of the concepts of Nicolai Tesla. The facts shared about our current energy delivery system are a bit shocking; we’ve spent over $1 trillion in infrastructure and produce more than 40 billion disposable batteries each year.

The demonstration in the video starts about 6:30 into it. At first we see a flat panel television powered wirelessly from about 6 feet away, then the T-Mobile G1 powered from the same distance. The thought of new TVs coming with WiFi and WiTricity standard would mean just hanging it on the wall with no cords to run. We can also image cellphones that have a battery only for backup purposes when you were not near a transmitter.

The power transfer occurs between two coils that resonate at the same frequency and only that frequency. This remind us a bit of Orson Scott Card’s fantasy communications device from the Ender’s Saga.

WiFi Mapping With A Smartphone

August 26, 2009 by Brett Haddock 16 Comments

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Not so long ago, mapping WiFi required a laptop, GPS, a big antenna and Kismet/NetStumbler. Today’s smartphones have replaced even this task. For those of us running a GPS and WiFi equipped Windows Mobile phone, WiFiFoFum is an excellent and simple solution, as well as a great companion for installing an AP. Continue reading “WiFi Mapping With A Smartphone” →

Adding A DisplayLink Monitor To A Linux Router

August 24, 2009 by Matt Schulz 14 Comments

slugterm_dl

Routers aren’t just for routing network traffic any more. With the help of alternative operating systems such as DD-WRT, Tomato, and OpenWrt, routers are now extremely customizable and can be utilized to suit a number of needs. The main issue with projects built around routers is the need to telnet or SSH into them to get to a console. [Sven Killig] came up with a useful solution that utilizes the USB ports available on an Asus router to display video on a DisplayLink device, allowing a user to sit down and use the device as though it were a physical terminal. This would be a good DIY alternative to commercially available routers that display network graphs, system information, incoming email, and other data.

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

icmptx

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

ez430 (Custom)

[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.