PCB Trace Antenna

August 5, 2010 by Jakob Griffith 19 Comments

If you’re working on a device that includes RF wireless, [Colin’s] Guide to PCB Trace Antenna Design might clear some headaches when sending off for PCBs. While it is directed at devices transmitting at 2.4GHz, the techniques and recommended equipment (read: espresso smith charts and network analyzers) should work for almost any frequency. While trace antennas aren’t as easy to implement as a measured wire, the space benefits make up for the difficulty. Unless you don’t mind how larger your project is, did someone say cantenna?

Graphic Calculator As A Spectrum Analyzer

July 29, 2010 by Mike Szczys 9 Comments

[Michael Vincent] turned his TI-84 Plus into a spectrum analyzer. By running some assembly code on the device the link port can be used as an I2C bus (something we’ll have to keep in mind). After being inspired by the cell phone spectrum analyzer he set out to build a module compatible with the calculator by using an I2C port expander to interface with a radio receiver module. Now he can sniff out signals between 2.400 and 2.495 GHz and display the finds like in the image above.

[Thanks Cecil]

200 Mile RF Transmitter (and High Altitude Balloon)

July 27, 2010 by Jakob Griffith 48 Comments

If there is one thing we like, it’s a fellow hacker so enthusiastic about his or her work that they write the article practically for us by including as much detail and information as possible.

In this two part hack, [Scott] wrote in to let us know not only about a high school built high altitude balloon, but also his $5 long range RF transmitter. The former is simply GPS and video data logged over the flight, but [Scott’s] specialty comes in the latter. A 74HC240 octal buffer is using to amplify the signal (Morse code) from an ATTiny44a with a 29MHz oscillator, producing a usable signal as far away as 200 miles.

It is low bandwidth, but if you’re looking for a simple transmitter in your project and need something with more power (and a smaller package), this might be the ticket.

Alternative Morse Code Keys

July 25, 2010 by Mike Szczys 18 Comments

Add a bit of interest to your radio equipment with one of these unorthodox CW keys. [OH6DC] has been hard at work posting almost sixty of these hacks. Above you can see an alarm clock whose snooze button acts as the key, and a nail clipper used as a key. There’s a banana , a cross-country ski shoe , and a toaster key. The rest you’ll have to see for yourself. Any of these would work perfectly with that Morse code keyboard you’ve been wanting to build.

Terminal Node Controller In A Router

July 23, 2010 by Mike Szczys 17 Comments

[Andrew] used a DSL router to make his own Terminal Node Controller. This will become part of an APRS-IS network, an Internet-based network built by amateur radio operators. The router used here is a Dlink DSL-502T with an AVR based TNC module attached to the serial port header. The phone line connector and its accompanying hardware have been removed to make room for the TNC module, which is supplied with 12V via that red wire. When the router boots up it sends data to the serial port header so the firmware on the TNC needed some tweaking to accommodate this (yay for open source).

Want some more APRS goodness? Check out this AVR APRS tracker.

Wifi Hotspot Powered By Wind Turbine And Solar Panel

July 20, 2010 by Caleb Kraft 19 Comments

[youtube=http://www.youtube.com/watch?v=z-MZmQqxrYM]

Students at the Rochester Institute of technology have put together this WiFi hotspot that is powered by a wind turbine and a solar panel. It gets its signal through a parabolic antenna pointed at a near by building and repeats it for use in the vicinity. They are using a 30W solar panel, along with a 1/4 horse power 90V DC motor to charge two 6V batteries in series. On a windy day, the turbine has yielded 120W. Something interesting to note is a comment they made about blades. Though the ultimately decided to mimic a commercial design for wind turbines, they found the most efficient to be a single wood prop. Unfortunately, that prop was destroyed.

[via HackedGadgets]

Building A Remote Control

July 18, 2010 by Mike Szczys 12 Comments

Here’s a homebrew remote control that [Jad Berro] is developing. He’s using a tank robot to test it out but eventually he plans to use it to control an RC plane thanks the 434 MHz wireless module inside. There’s no shortage of input, with two analog sticks from a PlayStation controller, several momentary push buttons, and some toggle switches. Although it’s not shown in the picture above there is also a 16×2 character display that serves as part of the interface. With a navigable menu the only limit to what you can do is the programming space available on the ATmega168 that inhabits the homemade Arduino board at the heart of the system. It certainly would give the robot remote from Friday a run for its money.