Author Archives: the machinegeek

GNU Radio demo: ultrasound data transmission via a laptop

Here the open source GNU Radio companion program is used to demonstrate the transmission of data from one laptop to another using frequency shift keying (FSK). They use an audio carrier frequency of 23 kHz. You can download the code for the GNU Radio companion flowgraph at Anfractuosity.com.

Convert optical mouse into Arduino web cam

Franci has written this tutorial describing the process used to convert a mouse into an Arduino web cam. In addition to the Arduino, all you need are an Ethernet shield, an optical mouse with ADNS-5020 sensor and a 10K ohm resistor. “An optical mouse uses a small camera that records the surface to calculate movements […]

MIT unveils Android App Inventor2

The App Inventor group at MIT have unveiled App Inventor2. You may be familiar with the App Inventor project when it was previously featured. (At that time it was known as Google App Inventor.) Essentially it helps you build Android apps using a graphical interface which is useful for quick coding and debugging, and is […]

Asterisk PBX on R-Pi

While you don’t hear quite as much as you did a few years ago about Asterisk, the free, open source framework for building communications applications, there’s still an active community developing and extending the code. The software essentially allows you to run your own VOIP Private Branch Exchange (PBX) on your home computer. The crew […]

Ham Radio Linux LiveDVD Ver. 14 supports RTL-SDR, HackRF and more

Andy, amateur radio operator KB1OIQ, has released the Version 14 of his Ham Radio Linux LiveDVD containing programs focused on amateur radio and SDR operations. This is a remastered version of Ubuntu Linux. As of version 13, there are 32-bit and 64-bit versions available, as well as an image for the PengPod 1000. This version […]

Linux SteamOS beta available for download

SteamOS is the currently-in-beta Linux-based operating system that will power Valve’s new gaming-PCs-turned-consoles. While the Steam crew has been busy readying 300 beta Steam Machines, they’ve taken the time to release the code for download by Linux enthusiasts. As they describe it, SteamOS Beta is the first public release of our Linux-based operating system. The […]

Android privacy controls appear, disappear in 4.3 – 4.4 transition

Apparently what “the Google” gives, “the Google” can take away. Recently Android was being lauded for adding additional privacy controls to Android 4.3+, allowing users to install apps while denying some of the apps’ attempts to collect the user’s data. This feature was accessible by installing a tool like App Ops Launcher (pictured above.) However, […]

Ford Traffic Tamer App challenge

Ford is currently sponsoring the Traffic Tamer App Challenge aimed at solving the issue of traffic congestion in the city of London. Part of this challenge encourages developers to use OpenXC in their solution to address the problem. Submissions are open until January 15th, 2014. The use of Ford’s OpenXC platform is encouraged, but not […]

MSP430TCH5E MCU integrates haptic and cap touch sensors

video platformvideo managementvideo solutionsvideo player TI has announced their new MSP430TCH5E microcontrollers which include haptics and capacitive touch capabilities on one chip. This allow users to add vibrational feedback on capacitive touch buttons, sliders and wheels, as well as capacitive touch screens in designs. The Immersion TouchSense technology enables 122 different haptics effects, including effect […]

HOPE-X half price tickets Wednesday

Our friends over at 2600 are once again offering a discount on tickets to their 2014 conference: In case you weren’t one of the lucky ones who managed to snag a discounted ticket in November, we’re having a special $99 ticket offer this Wednesday (December 11, 2013) at 2 pm ET. HOPE-X will be taking […]

Advanced Hard Drive Caching Techniques

Petros Koutoupis at Linux Journal posted detailed information regarding hard drive caching techniques. Users of traditional hard drives who’ve been considering a switch to a solid state drive (SSD) should find this particularly interesting. Petros describes, Even today, the consumer SSD cannot compare to the capacities provided by the magnetic hard disk drive (or HDD), […]

SkyJack open source drone hacking project

SamyKamkar developed this seriously cool project to wrest control of civilian drones away from their owners. SkyJack is a drone engineered to autonomously seek out, hack, and wirelessly take full control over any other drones within wireless or flying distance, creating an army of zombie drones under your control. Using a Parrot AR.Drone 2, a […]

Nooelec RTL-SDR giveaway at AmateurRadio.com

AmateurRadio.com has teamed up with Nooelec.com to give away RTL-SDR packages to 10 hams. To be eligible to enter the competition, you must be a registered amateur radio operator, and you must comment on the competition page. The prizes are: Two (2) Complete HF sets including NESDR Mini receiver and accessories; Two (2) Complete Touch […]

GRCon13 video: Some More of Your RFz Are Belong to Me

At the recent GRCon2013, SDR guru Balint Seeber delivered this presentation on using GNU Radio to create new blocks and prototype flowgraphs relating to FasTrak RFID (used in traffic toll collection system), MUltiple SIgnal Classification (MUSIC) Direction Finding, RADAR Detection and Multi-channel Decodings.

Rtl_fm Guide: The long lost documentation

Kyle Keen has written up documentation on his Rtl_fm utility, which enhances RTL-SDR operation on older PCs. Rtl_fm is a little utility I wrote for the RTL-SDR project. The program was made to fill a gap in software defined radio: all the computers weaker than a Pentium 4. Basically, an Atom processor processor does not […]

Decoding radio-controlled bus stop displays

Oona Räisänen (a/k/a Windytan) is a self-taught signals and electronics hacker from Helsinki, Finland, who is fascinated by mysteries, codes and ciphers, and vintage tech. She’s previously written regarding the use of digital transmissions carried on FM broadcast subcarriers as a means of supplying data to digital information signs used at bus stops.

Constant current circuit for IR LEDs

The crew from AnalysIR reports they have written up an article on constant current circuit for Infrared LEDs – similar to that in the USB IR Toy. They compare the various methods of driving IR LEDs, including a series resistor and a circuit driven by an NPN transistor, and how to design your circuit for […]

RTL-SDR + SDR Radio + Funcube Sat

Amateur radio operator N4JTC has written a blog post about his experiences using the RTL-SDR dongle to receive the Funcube Satellite. With the recent record number of cubesat launches this month most Amateur Radio enthusiasts been busy, myself included. There hasn’t been a better time to get into receiving these satellites. With the inexpensive hardware, […]