Notes

GNU Radio Resources

I’ve been messing about with GNU radio using a ezcap DVB-T USB device which cost only about £10.

On Ubuntu I used this script. That took a while.

Then I used the GNU Radio Companion to make a Spectrum Analyser and a recorder using this and this as a reference.

Notes

Boilerplate Nginx Confg

Nginx is awesome. Fact. This is the a really simple config to just serve up files from  /usr/share/nginx/www

Notes

Books to read in 2013

One of my new years resolutions was to read more books (at least, less technically heavy books). The following is my list so I can review it at the end of 2013.

Cyber War: The Next Threat to National Security and What to Do About It

Beyond Good and Evil (Penguin Classics)

Clockwork Orange.

The Cathedral & the Bazaar

Flesh and Machines: How Robots Will Change Us

Buddhism

Game Theory: A Nontechnical Introduction

The War of the Worlds

How to Live Off-grid

Notes

Laser Cut Raspberry Pi Robot

Raspberry Pi Robot

Just awaiting a few more bits before I mount the Raspbery Pi on the top of this little robot I recently had laser cut by the awesome Razor Labs. I’ve got a webcam to attach to the servo which I intend to use to provide machine vision using OpenCV. Watch this space, everything to be uploaded to Github.

Notes

Raspberry Pi Pinout clarification

The Raspberry Pi Wiki provides a pinout which doesn’t seem to map what sysfs thinks. The link provides clarity, I’ve tested the information and it works.

Notes

Blink the Raspberry Pi OK LED

Notes

It’s arrived! The much awaited for Raspberry Pi. Time to get hacking!

It’s arrived! The much awaited for Raspberry Pi. Time to get hacking!

1 Notes

Sugru Bath time rescue

We lost the plug for our baby bath, whoops!

The thing is baby baths are very cheap as they are only a blow molded piece of plastic. As the plug is bespoke size and no one sells replacements the only options are to either replace the entire bath consigning the existing bath to recycling/landfill or to improvise a new plug.

Sugru Bathplug

I had been tempted to just buy another bath, after all they can be bought for <£10, which given I value my time more than money would previously of been the sensible option. I believe it is this logic that requires a quantum shift to reduce our over consumption of materials.

This is where Sugru solved the problem. I already had a pack but had yet to come up with an imaginative use. And thats the problem. As Sugru hasn’t hit critical mass like superglue its a tool you potentially leave for important jobs currently.

Sugru

The above fix took only a couple of minutes to fashion having molded the Sugru around an M10 Stainless steel nut. Once dry it produced a watertight seal and a happy clean baby.

I’ll be reaching for Sugru more readily now and suggest you do the same.

3 Notes

The Tortoise and the Hare (http://bit.ly/1afKiT). A laser cut dial gauge for monitoring the speed of things. Created using Ponoko/ Razor Labs (http://bit.ly/b8utIN). The dial moves by the rotation of a servo mounted behind the gauge. Controlled with an Arduino. Commands sent from a small python script which obtains data from Pachube (http://www.pachube.com). If you would like a gauge, get in touch.

The Tortoise and the Hare (http://bit.ly/1afKiT). A laser cut dial gauge for monitoring the speed of things. Created using Ponoko/ Razor Labs (http://bit.ly/b8utIN). The dial moves by the rotation of a servo mounted behind the gauge. Controlled with an Arduino. Commands sent from a small python script which obtains data from Pachube (http://www.pachube.com). If you would like a gauge, get in touch.

5 Notes

Using Python and an Arduino to get data from Pachube

The dial I created was mostly for server monitoring but before that I figured I would try and hook it up to Pachube to obtain the speed of something. I went hunting for something on Pachube that had a speed elements. I found that there is a plentiful supply of massive ships that post AIS data like this awesome tanker http://bit.ly/eARKxw and she has this Pachube feed http://bit.ly/fQMKQT. Cool.

The biggest thing with ships is a limited amount of variation in speed. Which makes testing really really boring. So having overlooked perhaps the largest contributor of data to Pachube, namely weather monitoring stations, I changed my plan and started to monitor the wind speed of a place in New Zealand. http://bit.ly/hcvkpq

The system is really simple. I get data from Pachube using their API with a simple python script this then talks via the serial port to the Arduino and changes the position of the gauge. Simple.

I’ve put all the code up on GitHub at https://github.com/gadgetlabs/DialGaugePachube

The code is simple but could benifit from additional error handling if you plan to use it properly. The Arduino code is based on code from Maurice Ribble http://bit.ly/tiHhK.

In terms of hardware I haven’t posted a diagram because it is really simple. I power the Arduino over USB. I share a ground with an external 5v power supply to drive the servo and connect one signal write between the Arduino and the servo. I actually have a Netduino so I’m going to make an ethernet controlled dial very soon.

I might try making other variants of the gauge at some point in the future because I’m hooked on Laser Cutters now.