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DDS Sine Sweeper

Submitted by Al on Thu, 02/21/2013 - 23:52

DDS Sine SweeperIt's about time for some hardware, so here is the DDS Sine Sweeper, a sine source which outputs a sine wave from 1Hz-40MHz.  It's cheap and easy to build and all the plans and software are freely available.

From time to time I found myself needing  a separate signal generator.  In the back of my head I was thinking of just something simple but I also wanted to play about with DDS (Direct Digital Synthesis), a method of creating a waveform digitally.  This allows precise control over the frequency from a microcontroller, allowing you to set the frequency and even jump to another very quickly.  Although it does have drawbacks the simplicity was a winner for me.

RTLSDR Scanner

Submitted by Al on Fri, 02/01/2013 - 23:50

Screenshot 1

Last year while developing Linux drivers for digital TV, Antti Palosaar noticed a hidden debug mode, which allowed you to sample relatively large chunks of radio spectrum.  Thanks to this the RTL-SDR library was born and Software Defined Radio was available on the cheap, after all these dongles tend to cost less than £20.

A little while ago I uploaded my contribution to this, a GUI called RTLSDR Scanner, to GitHub.

GPX Logger

Submitted by Al on Thu, 01/03/2013 - 18:20
Happy New Year!

GPX Logger is now available on Google Play for Android, it's a simple app to log GPS location data to a memory card. I've designed it as a data logger but it will also show your location on a map and display information about satellite signal strength.

If you use this app for anything out of the ordinary I would be interested to hear about it. Please let me know in the forums.

UK Quake

Submitted by Al on Tue, 12/18/2012 - 01:22

UK Quake Time for another Android app, this time it's UK Quake which maps out the recent earthquakes in and around the UK.

Now Fracking has been given the go-ahead in the UK will rumours about extra quakes come true? Track them using this app.

Cell Map

Submitted by Al on Thu, 12/06/2012 - 15:49

Cell Map I've just released Cell Map, and Android app that locates the cell towers your phone is connected to.

Designed for those who want to find a transmitter with a good signal or just the curious, I hope you find it useful.

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