Bits of SDR

The hackspace is a bit quiet at the moment, we’re waiting for some room to set up our laser cutter.  NSME are kindly giving us some space and have even provided some fire extinguishers, optimistic that they are.  Hopefully by the beginning of April we will have space for it.

In the meantime, I did some tooling around with the RTL SDR dongle, the software support for which has come on marvellously, and after some fun following some guides on the ‘net, we were able to pick up the ADS-B location broadcasts of airplanes overhead – albeit in a very small range, due to the antenna in use that isn’t designed for 1.09GHz.
For the curious, I originally started with the rtl_adsb library that comes with rtlsdr these days (also worth investigating the rtl_tcp server if you want to leave your dongle in an RPi…).  This puts out the decoded broadcasts to an almost human-readable level.  I then installed the VirtualRadar software (which is cross platform) . . . which didn’t decode the messages at all (linked together via netcat).  It confirmed it received messages, and that they were not badly formatted, but couldn’t decode them either.
I then tried using this guide and used the gr-air-modes application instead.  The script it recommends has been replaced with rx_modes instead but the syntax is the same.  This wasn’t too painful for me as I already had gnuradio installed.  For those that don’t though, the latest in Ubuntu 12.10 is compatible with the osmocom extra sources.

Light painting

A short and belated write-up of the light painting session we held Monday before last.

It wasn’t entirely dark:

There was a full moon and the sky was clear:

Nevertheless, a bunch of us gathered and ventured into the abyss of Delapre Park:

We played with torches:



We played with flashing lights:

We played with fire:

But soon we retreated to the warmth of the clubhouse at NSME:

Where there were plenty of trains:

And some shiny objects to laser:

Many more photos on Flickr, tagged northackton.

Site refresh

Those not following this site by RSS will have noticed the website has become a bit more stripped back recently. The latest version of WordPress doesn’t work so well with the old theme, so it’s had to leave us.

Any opinions on the new one? Too plain? Just the facts? Put them in the comments.

Regular pub meets

We’re going to start having regular pub meets to chat outside the clubhouse, where food and alcoholic drink are both available.  They will be every other month, starting Wednesday 13th February, at the Charles Bradlaugh pub.  See our Calendar or Facebook for details.  

Invite your friends!