Greece and the EU

Wed Jul 8, 2015 by brett

If there’s one other casualty of the current crisis in Greece, its my Euro-optimism. Over the past couple of weeks I’ve transformed from being optimistic about the Euro, to being totally pessimistic about it.

The only way the Euro can work is if there is a transfer of wealth from the richer members of the zone to the poorer members. In return, the richer members get a lower exchange rate, which is massively beneficial to their exporters. If this transfer doesn’t take place, then the Eurozone will collapse.

Python OAuth2 failing with X509 error

Mon Feb 9, 2015 by brett

I’ve just spent about 20 minutes trying to authenticate with Twitter using the Python OAuth2 module. I kept on getting an X509 error, specifically:

ssl.SSLError: [Errno 185090050] _ssl.c:343: error:0B084002:x509 certificate routines:X509_load_cert_crl_file:system lib

The solution to this is that the cacerts.txt file in the Python installation is only readable to the root user / wheel group. In order to fix that up, first find the cacerts.txt file:

find /Library/Python/ -name cacerts.txt

Then modify the permissions on the file:

sudo chmod 644 /Library/Python//2.7/site-packages/httplib2-0.7.7-py2.7.egg/httplib2/cacerts.txt

Note that the URL endpoints for twitter on the python-oauth2 Github page are currently wrong. To use the “Twitter Three-legged OAuth Example” change to, etc.

The Raspberry Pi 2

Sat Feb 7, 2015 by brett

The Raspberry Pi 2 was announced a week ago, and I decided to get one to use as a media centre. Mine arrived yesterday.


Back to blogging

Thu Feb 5, 2015 by brett

Well, it’s been a loooonnng time since my last blog entry. One of my resolutions for the new year was to do more blogging. Despite this, I haven’t blogged anything for the whole of January. OK, so this stops now. As of today I am starting to blog again. Even if it’s just a short and almost meaningless entry about how I’m going to start blogging again.


Fri Aug 22, 2014 by brett

Last Monday we bought a house in Brighton. I wasn’t sure it was going to happen. Genetically I’m predisposed to worry about stuff, and right until the last moment I was thinking of disaster possibilities. We were supposed to exchange contracts and settle at 2pm. We spoke to the vendors and they were saying that they couldn’t possibly be out of the place before 2pm, so we decided to travel down by train and get there around 3pm. We got final confirmation from our solicitor that the settlement had happened at 3pm, while we were still on the train. We got to the house, and the vendors were still in the process of moving out. We grabbed some keys and went and grabbed something to eat. By the time we came back, the vendors had left and the place was ours!

Jeremy Howard talk about the Data Science Revolution

Mon Aug 18, 2014 by brett

Here is a talk about machine learning given by Jeremy Howard which is part of the Exponential Finance Conference series which is well worth watching:

The Data Science Revolution (Jeremy Howard) - Exponential Finance 2014 from Exponential Conference Series on Vimeo.

OpenSCAD rocks the house!

Mon Aug 18, 2014 by brett

Last night I was trying to print a camera lens clip that allows you to clip your camera lens to your camera strap. Unfortunately the clip for the strap wasn’t wide enough. Fortunately the OpenSCAD files were included, and all the settings were in the file. It was simply a matter of changing the appropriate variables in the OpenSCAD file and then exporting the model.

The great thing about OpenSCAD is that it is like a programming language for your 3D models. As such it makes parameterising the important parts of the 3D model easy.

Da Vinci 3D Printer Arrives

Sun Aug 17, 2014 by brett

Yesterday my XYZ Da Vinci 3D Printer arrived. I had a really fun day setting it up and doing some test prints. The first print I made was the “key chain” print that is on the firmware. This created a rather lame “XYZ” logo that I assume you can attach to your keyring.

IMG_0099.JPGThe CD that came with the printer only has Windows versions of the XYZ Printer software, despite proclaiming Mac versions as well. Fortunately, the software is downloadable from their website.

Next, Helen created a model in XSI of an egg cup that looks like a bird’s nest. She exported it to Blender and then we created an STL file which we then imported into the XYZ Printer software. The print for this took about 3 hours, and the results were less than perfect. The egg cup still looks pretty cool though.


This morning I printed a 3D printed shell and ordered an Arduino so I could reset my filament cartridge as described here.


So far I’m pretty happy with the printer. It was pretty cheap at £500, and I’ve really enjoyed playing around with it. I’m keen learn a lot more about 3D printing, and I think that this printer is a great one to start with.

Configuring a Jaalee iBeacon Transmitter

Sat Jul 19, 2014 by brett

I received 5 iBeacon transmitter units from today. They arrived unassembled, so I put them together and configured their local names with my iPhone.

The first hurdle I found in setting them up was getting the battery in the right way around. Each unit comes with a watch battery, and you need to have the side with the plus sign facing away from the circuitry.

In order to see the device, install Jaalee’s eBeacon app onto your iPhone. When you run this app, you should see your iBeacon device with the name “jaalee”.

When you connect to the device it will prompt you for a password. The default password is ‘666666’.

You can change the local name for your iBeacon. I wrote a utility to help generate the code needed to change the name and have put it on Github here as “jaalee_rename”. I also have instructions in the README file explaining how to change the local name for the iBeacon.

The next steps for me are to write a simple app that uses my beacons. I am thinking of an app that will automatically let me team know via email if I am running late in the mornings.

Why US GDP is higher

Mon May 19, 2014 by brett

It seems that US GDP always seems higher than European GDP. A fact that US pundits always seem to crow about. It seems that there may be a reason for this (other than the fact that the US is a dynamic environment to work in). As Philip Greenspun reports on his blog, if health and education are privatized (as they are in the US), then there are some additional monetary of this reflected in the GDP numbers that are excluded in countries with socialized health and education programmes. A conclusion that Philip attributes to Piketty.

Another thing that inflates GDP is that Americans spend a lot more on litigation than Europeans.

I would be interested if someone did an analysis on how much of an effect this has on GDP.