Category Archives: RF

Defcon 19: build your own radar system

At the Defcon 19 (2011) conference Michael Scarito demonstrated how to construct your own radar system. The project is based on a design by Dr. Greg Charvat from MIT and uses synthetic aperture techniques to generate a two- or three-dimensional image. (You can read Dr. Charvat’s research paper here.) The hardware operates in the 2.4 […]

How to find your location using GSM data

Boris Landoni writes to call attention to his interesting article in Open Electronics describing how to find your location using GSM Cell ID data: The radio mobile network is made up of a number of adjacent radio cells, each of which is characterized by an identifier consisting of four data: a progressive number (Cell ID), […]

SDR Sunday – monitor web SDRs and decode digital data

Want to try out software defined radio (SDR) before you buy or build a rig? Or do you just want to see what all the ham radio chatters about? Then check out the online SDRs available for your listening pleasure at WebSDR. This unique website lists dozens of online radios which you can click on […]

Adding Bluetooth to your MSP430 project

NJC’s MSP430 Launchpad Blog has posted this tutorial on how to add Bluetooth to an MSP430 project. He chose the RN-42 module and designed his own breakout board (shown above). He writes: The RN-42 module, which is available at SparkFun electronics and Mouser, is a very cheap and simple way to use Bluetooth in your […]

IM-ME jams APCO P25 digital comms

APCO Project 25 is a digital modulation protocol used by a growing number of public safety radio systems and to a limited extent by Amateur Radio Operators. APCO P25 radio transmissions are capable of being monitored by scanning receivers from Radio Shack, GRE and Uniden. That is, unless the agency monitored decides to encrypt their […]

RHINO

The University of Cape Town in South Africa is developing an open source SDR project known as RHINO, which stands for Reconfigurable Hardware Interface for computiNg and radiO. Reconfigurable Computing is an attractive computational technology, allowing an almost limitless set of possible solutions to any particular problem. It does this by providing an effective compromise […]

Arduino TNC

Amateur radio operators use various digital data modes for radio communications. One such mode is known as packet radio, which transmits data in groups or “packets” of bytes. As described by the ARRL, “packet radio allows improved throughput and error control. The basic protocol for packet radio is AX.25. Transmission speeds typically range from 300 […]

Bluetooth Morse keyboard assists the disabled

In an effort to assist computer users with disabilities limiting their keyboard dexterity, the crew at Zunkworks developed this wireless Morse code based keyboard interface device. The user keys in the desired characters using the “dot” and “dash” buttons on the left of the board and the Arduino based device converts these Morse code characters […]

ARISSat-1/KEDR test transmissions planned from ISS July 30-31

We know, we’ve been down this road before with the ARISSat-1, but this time they say it’ll work. Test transmissions from ARISSat-1/KEDR are scheduled to begin four days prior to deployment at 19:15 UTC on July 30 and then continue until 1430 UTC on July 31. The satellite will be connected to an external antenna […]

GNU Radio conference 2011

The GNU Radio project has announced plans for their first conference, to be held September 14-16, 2011 at the University of Pennsylvania. What is GNU Radio? GNU Radio is a free software development toolkit that provides the signal processing runtime and processing blocks to implement software radios using readily-available, low-cost external RF hardware and commodity […]

Video: DSP/SDR basics

Here’s Jeri Ellsworth’s latest video, explaining the basics of DSP and SDR for beginners, and how to build a digital direct conversion receiver (SDR) using sampling detectors and FPGA DSP processing. (If you want to skip the silly cat portion of the video, start at 1:25.) The links referred to in the video are below: […]

USRP 101: unlocking wireless PC locks (and freeing dolphins)

We’ve been interested in the Universal Software Radio Peripheral (USRP) SDR and the associated open source GNU Radio software for some time, but the $1500+ cost has kept the project on the back burner. Nevertheless, we always like a good story about RF hacking with the USRP. Corey and Max saw a wireless USB Proximity […]

Quick and easy wireless using R/C and PIC 18F452

Chris from PyroElectro writes to inform us of his new wireless project: It takes a standard hobby R/C radio transmitter/receiver system and interfaces it to a PIC microcontroller to control a Motor and LED brightness. Named the Quick and Easy Wireless system for it’s off-the-shelf style. Project details including schematic and C code can be […]

Freescale’s MC13260 two-way radio chip

Freescale’s MC13260 System-on-chip two-way radio is one chip to watch for. Now in the “introduction pending” stage and highlighted in this video from the recent FTF 2011 conference, it promises to be a one chip analog/digital radio solution. Preliminary design specs show RF coverage from 60-960 MHz, comprehensive digital radio mode coverage including DMR, dPMR, […]

Amateur radio study guide has much information about electronics

Ham radio is nothing new, however if your new to electronics, or interested  in becoming a ham, we suggest reading one of Dan’s self-study guides. The RMS value of an AC signal is the voltage that causes the same power dissipation as a DC voltage of the same value. (G5B07) For an AC signal with […]

XBee wireless interface tutorial

Chris from PyroElectro has posted this tutorial on interfacing with XBee. He writes: Getting started with XBee can be tricky, even though it shouldn’t be. Here is a drop-dead simple guide to using XBee modules out of the box. The tutorial shows you how to build a wireless interface with XBee modules between two PIC […]

App Note: wireless home security implementing KEELOQ® and PIC®

KEELOQ® is an authentication system designed by Microchip. It’s based on a proprietary, non-linear encryption algorithm that creates a unique transmission on every use, supposedly rendering RF replay attacks useless. The algorithm uses a programmable 64-bit encryption key unique to each device to generate 32-bit hopping code. In this new app note, Microchip presents a […]

Hacking a PIR RF signal with PIC 12F683

Deepak from Mindfront.net acquired a PIR alarm sensor module which transmitted a digital code over 433 MHz RF to signal an alarm receiver. The problem: he didn’t have the factory receiver. So he set out to sniff the transmitted RF signal using a RCR-433-AS receiver module with the data out fed into an oscilloscope. This […]