Playing with the RTL SDR

Posted on 27/04/2012 by widget

So the hackerspace will imminently have a number of Realtek-based SDRs as demonstrated last meeting. An SDR, or Software-Defined Radio is a very flexible device, that performs the equivalent of a “raw recording” of a portion of the RF spectrum and then the raw samples can be processed in any way you like on your computer.

So for example, you can pick up FM radio, the pager network, transmissions from the ISS, or aircraft transponders. Working GRCs will be posted on the blog

We’re going to try doing some of these things in the space over the next few months, the exact dates will be discussed on the list. If you’d like to try this, here’s some links:

Gnuradio. You will probably need this build script for latest release
The RTL binary itself
The GnuRadio Companion source block for RTL

Another useful resource is the subreddit for it.

Minimus workshop #1

Posted on 06/03/2012 by widget

Monday was a good day for hacking; we had an impromptu Minimus workshop. This was surprisingly successful, attendees were able to get their boards programming in Windows or Linux as to their preference, and then start diving into code.

The devices aren’t as friendly as the Arduino boards, and the example source code will compile but not always run without extensive tweaking, but by the end of the session, in addition to a medley of flashing lights, we also had a one button keyboard and a virtual serial port that reported its button state.

Due to demand we will run another of these in April (2nd or 16th, TBC) and again will have Minimus boards available for use on the day or purchase. There’s no fixed cost for the workshop, but donations are appreciated. If you have a Minimus board or are interested in a step on from Arduinos, why not come past?

As a reminder to Northackton members who are also NSME members, their auction is on the 13th of March.

Layzor cutting

Posted on 22/02/2012 by widget

On Monday we visited Martin’s laser cutter, as once he installed it at his house with a water tank for cooling, it’s not particularly mobile. He showed us some of the many things he’s made for his blog, and his lightbox for photographing them.

Onto newer things, we printed a NortHACKton stamp for visiting passport-holders. After learning how to etch rubber, I then provided an object lesson in the power of cyanoacrylate glue by adhering to the stamp rather effectively.

Secondly I had made an SVG of a bokeh rig for my camera for Martin to convert and cut, which produced a passable first attempt at a kit that can fit to my D3100. Not all of the pictures were good, but it was certainly a learning experience. See Martin’s blog for the design, and the results are here, in the February pictures of this set.

March’s meetings – we meet in the space as normal for Monday 5th, and on the 19th there will be another pinball evening in Bedford. See the mailing list for more details.

TWENTY TWELVE

Posted on 10/01/2012 by widget

So, the first meet of the New Year was on the 9th January, and we all brought our presents along. I brought a model steam carriage kit, that was an exciting puzzle to solve as the instructions were particularly vague, and Alan brought polymorph to play with.

The polymorph was slightly more successful than the engine which due to some presumed error in construction, does not self-propel. This is due to the piston being unable to turn the flywheel, itself due to the axle somehow jamming in place. It still looks moderately elegant.

Next meeting 23rd January 2012.

A late chainmail writeup

Posted on 14/10/2011 by widget

This post is unfortunately almost two weeks late, but last Monday, Pat gave a chainmail workshop, similar to Martin’s at Nottinghack. This covered the easier European and Japanese styles and also how to make rings from fencing wire or similar. Many scraps of chainmail were produced, but nothing to rival Pat’s half-finished chainmail shirt!
Nick continued to resuscitate aging hardware in Linux and we discussed methods of supplying Internet to the NSME clubhouse. Via a landline this would be expensive, wireless access of the nearby BT Openzone hotspot, or 3G personal hotspot appear to be the more affordable ways forward…
Next date for the space: Monday 17th October.